My 76 pinto has recently developed a problem that ive had in the past and cured once before. It'll do just fine in town, but get out on the highway about 50 or faster...and it will run fine for a mile or two, but then all of a sudden it starts misfiring real bad and losing speed, even with the pedal to the floor, and after downshifting...get down to a certain speed and it will be fine again....until you reach the normal highway speeds again. Â Ive replaced both fuel filters (the one behind the electric fuel pump i had to install, and the one up by the carb. Like i said its done this be before and i cured it with a fresh tune up. New plugs, wires, cap, rotor and filters. But, that has only been 6 months and maybe 5,000 miles ago. Theres no reason i should need to replace that stuff again already. Theoretically it shouldnt be fuel related, because you use more fuel in town than on the highway. The plus wires havnt layed on the hot exhaust manifolds and burned the insulation or anything like that. The only thing i can think of is, there is a burnt valve in cylinder number three. Maybe it has fouled. I dont know why the plug would make it do this, but its the only thing i can think of that could be solved by giving it a tuneup, and the burnt valve is the only thing i can think of that would have already fouled up something that is new. Whats odd is it never did this before the last time it happened and its been 2.5 years now and i know its had the burnt valve this whole time and its been on the highway alot. I just cant figure it out. The *only* way i can see it being fuel related is if the pump is weak to keep up with the CONSTANT demand of fuel on the highway, instead of the the inconsistant use of fuel intown...everytime the clutch is pushed in it would give the fuel pump a chance to refill the float bowl in the carb. Just a thought. Anyone have any ideas? Ive got a new head for my car just havnt got the time to put it on yet.
My 79 race car did something like that, but it was the pump. It checked fine for pressure, but did not do the CFM. Changed it, and it was fine. Was the stock mech. pump.
Do you have a vented gas cap?
Bill
No i lost the original cap and replaced it with a brand new locking gas cap. I think I still had the stock cap on it when it did it before tho. I dont think the new one is vented, not even sure the original one was either, but i dont know.
Hi...
I agree with the gas cap theory...try that first ...if the cap is not vented it can create a vacuum of sort`s after high fuel consumption and as a result ...fuel starving...as you slow down the tank has time to vent as consumption decrease`s...also you say it mis-fire`s...doe`s it pop back or start to surge or bog down? Just some thought`s...Hope they help! ;D
73pintogeek
No surging, it does pop real loud under the breather when i put my foot to the floor. It just starts misfiring real bad and bogging down and losing speed pretty bad, even with my foor to the floor. Im not sure that my putting the pedal to the metal doesnt actually make it lose speed faster....because it might, i didnt pay much attention to that. How do i make the gas cap vent if it is unventented? I can remove the cap and try running it that way, but if thats the problem how do i solve it? Drill a hole in the *top* of the cap?
The gas cap is something you should check, correct it by buying a cap made for your car. Another thing to check is if the distributer is advancing. Sometimes when you start the car, it is fine, because you aren't really putting any real demand on the engine. But then you get it out on the highway, and the distributer needs to advance, and it is stuck in it's original postion, and can't utilize the fuel now being introduced. Many times the vacuum advance is not working any more. Check it with a vacuum gauge, or take it off the distributer and zoop through it- if it doesn't move, it is inop. Also, check your coil, they can make a car behave badly-good luck
This cap was bought at the parts store for a 76 pinto sedan. The coil is about 2.5 yrs old, but it was a cheapie. Vac advance worked last i checked, i'll check it again. If the timing belt was off could that do it? I think my belt is old...
If the belt was out of time you would have less power overall, depending on the setting. If it runs fine then has issues, chances are it is not the belt. In the mid 70's car makers were forced to use a "self contained" venting systems. What this did was basicly vent into the intake or charcoal canister. When they did that, they stopped venting the gas caps. If your venting system has been messed with and you use a non-vented cap, there is potential for a problem. Check to see if the vent hose is not plugged or kinked.
You stated that you have an electric pump. Is a return line installed? Are you using the return as a vent? I know on my pintos the mech. pump has two fittings, one is a return to the tank.
Will the car have its problem if you stay in a lower gear and keep the rpms up?
Bill
I bet thats the problem right there. I plugged the return line. Ive used this electric pump now for about 2 years....had the car a lil over 2.5 years. The problem with that is it hasnt done it every time im on the highway, after i gave it a fresh tune up i went to kansas city the very next day and it ran fine. Thats about 200 miles each way. It made 27.2 mpg and had more power than its ever had before. Now the gas milage has dropped some and it doesnt have near the power. It was amazing what the tuneup did for it, but its a shame that power didnt last long. The reason i plugged the return line is because it was leaking gas out of it. is there another way to vent the tank? I havent checked to see if it still misfires if i leave it in a lower gear...dont see why it wouldnt tho. There are no charcoal canisters or anything on this car...no vents into the intake either except for the PCV system.
I would think about running a stock pump and lines, and replace the bad section of return line. It is all low pressure stuff, easy. The pump is a pain with that sheild, but with all the stock stuff it should run right. If you don't want to go thru that, you might want to get a reg. with a bypass (return). This might sound funny, but maybe you are getting too much gas. I doubt it, but maybe.
My vent line has a fuel filter on it and I have not had any problems (EFI).
Bill
I put an electric pump on it because mechanical pumps would work for about a thousand miles and then quit. I went thru 5 or 6 brand new mechanical pumps and finally the last one would not work at all. Thats when i got fed up with it, and put in the mechanical pump. I too wonder if im getting too much fuel. It's a possibility, but i think it is burning everything it gets, theres no black smoke. There is blue smoke when i rev it up, due to valve guides and a burnt valve, but i have never seen any black. I might try the regulator thing, i dont know. Going to clean that one spark plug too for sure.
Did you get all those pumps at the same place? I have never had any problems like that. You might have a problem with the fuel strainer in the tank, rust in the tank, or a bad fuel hose.
How do the plugs look?
That valve might not be helping either.
Bill
I didn't read about you having an electric fuel pump my first post-but my son had a similar problem with cheapie electric fuel pump- we replace it with a Holley and never had any other problems, but did you know the electric fuel pumps must be mounted lower than the gas tank? Even Holley suggests this mounting location. Check your pressure, along with all the other suggestions these guys have made, surely one of these solutions will work-- ;D
Good point ST!!! Some in line pumps don't like to pull the gas up out of the tank.
Bill
The fuel pump is mounted back by the fuel tank and yes is it below the fuel tank level. The first time the problem came up was long after the electric pump was installed. I gave it a tune up and that fixed it. Now then 5k miles or so later its doing it again. I think the pump is getting weak or as suggested is unable to pump because of a lack of venting. I dont know. 77Turbo - Yes all the pumps came from the same place (oreilly auto) but it tried 3 different brands. The last one was a carter which is a name brand. I think the lobe on the auxillary shaft that drives the pump is just bad, and that it has enough lift on it to run the pump until it wears out a little, and then thats it. Also, back when i was having problems with the mechanical pumps, i took the lines all off, and the tank and made sure everything was all clear. Also, when i replaced the filter behind the fuel pump here a week or so ago, fuel was gravity flowing out of the line when i removed the line from the fiilter. i had to plug the line because it wouldnt stop (that should verify the pump is in a good spot right there) and so that tells me the lines and strainer are clear, atleast up to there. I Guess i should check on that from there, but i really think the problem is ignition related. Anyone know how much volume i need to properly run a 2.3L? I think its providing plenty (if not too much, as suggested. This pump is supposed to put out 5 to 7 PSI, and i think i only need 4 to 6 PSI) Not sure on the volume. I'd like to go back to a mechanical pump, but im afraid i'd have problems every thousand miles again like before. I do have a spare motor that i am thinking about putting in soon. Maybe the mechanical pump will be fine after that (i hope! tho i do really like the electric pump for some reason) It's only got to last me until i get the rest of the parts and the motor for my 2.3 Turbo swap. Probably gonna be a while tho unfortunatly, and i need this car until then. My park avenue with 240k on its 3800 V6 just spun a rod bearing, and id rather have my pinto anyways!
Hey I still think it is your coil-see if it has oil residue on it, and it gets real hot--if you get an odor like a flourescent lamp ballast burning out, it is your coil--also, take your distributer cap off and push the shaft around, see if it moves--it it moves, you willscatter spark at rpm--be sure and keep us posted so we can see if we helped!!
Wow, thats..... I too have a daily driver park ave.
I have a good spare engine I would give you if you were closer. Well, you can have it anyway, just might not be cost effective.
There was a aux. shaft on ebay not long ago, might still be there.
Yes, please keep us posted, and good luck.
Bill
I pulled the spark plugs today. All of them have a little bit of a white powder looking substance on them. Its normal i think. I checked the fuel pump volume...in just the 5 seconds or so that i had it on, i filled up about 1/3rd of a 20 oz coke bottle. The pressure i cant test right now.but if its got the volume surly it has the pressure too? I havnt got to check the coil yet, or the distributor as suggested before. Is there anything in the carburetor that could make it do this? i am not a professional carburetor guy.........i dont know too much about carbs but i rebuilt this carb by myself, and adjsuted it with a vacuum guage. I checked the float level andall tht good stuff. Also, i dont know if this tells you anything or not but here goes. I had this problem before, and then on june 3rd i tuned it up. Never tested it or anything to make sure i have fixed the problem. Bravely the next day i took it on a 200 mile trip to kansas city. It ran like a striped butt ape. I would NEVER have guessed this thing to run like this. Pulling 80 mph on a hill and not even on the floorboard, and still gaining speed, and other things that just totally blew my mind. It had a TON more power. However that only lasted a few weeks and then it went away. Does this sound like a problem or is that just the new ness of the tuneup wearing off? If its a problem it might explain the misfiring problem.
That is kind of weird, seems like maybe you moved a vacuum line around and plugged a leak accidently when you did the tune up, then later the vac line slipped to its old leaking position. Vac lines are cheap, just replace them all to eliminate them. Also, how is your pcv valve? They can affect performance too. Make sure your distributer is tightend down also, your timing could be sliding around. There are so many silly things it could be, it's sometimes just a matter of spending a lot of time, just kind of pawing around on the thing til you see something amiss. I bet when you find this, it will make you want to slap your head! I've done it many times, I just understand myself better now, know I can overlook easy stuff by assuming it to be good.
Ive been there done that before. Anytime im under the hoodi kinda tinkering around. checking this and checking that. PCV valve is new, as are the vacuum lines. I kinda went on a spree and over the last 3 years, ive replaced just about everthing under the hood, except the motor itself, and the heater hoses (doesnt that just sound like fun? you know you want to replace the hoses for me..... ;D lol) I'll let you know what all i find. Im gonna see about the coil and have the control module tested too. I replaced it a few years ago when i got the car. It wouldnt start and the module was the problem. However i used the cheapest part i could find. Oops.
Hey my brain just squirted another possibility--is your carb tightend down? Check the bolts between the carb base and the carb! I overhauled a carb once and left those screws about finger tight- ran good for about 2 years and developed a very vexing problem, no power on the highway, hard to start. I was checking it out and when I removed the air cleaner element I bumped the carb and it shifted about 1/4 inch? Major forehead slap! Took off the carb, tighted the screws and then tightened the carb back down. Now it runs like a champ!
I'll check that but im pretty sure its tight. Im going to take my plug wires back to the parts store tomorrow and get them warrantied....awful funny it went away after giving it a tuneup last time. However, i did fill the gas tank up totally full tonite (i dont usually) and it is overfull (i "topped it off") and started smelling gas real bad. I went and looked and there is a little bit of a fuel leak back there. May just be because its filled to the brim with fuel, because it usually doesnt leak and its been so long since its been full. Could this have anything to do with my problem? I dont really think so, but if it is in one of the fuel lines back there (not likly tho since it doesnt leak all the time) it could be sucking air alongside the fuel and causing fuel starvation at speed (float bowl going dry). It could still possibly free flow the proper volume that way with no load on it (not pushing against the needle/seat) and then have problems again under load. Just a thought. I need to check it out too i guess. Geeze whats next i wonder. LOL. thanks guys. Ill keep trying stuff.
Keep in mind when trouble shooting this stuff- air, fuel , spark and compression must all be consistently present for good things to happen. If you have done a compression check and are satisfied with that, then go to the next item, and check that--consistensy is key here. Also, as you mentioned, how strong is the spark? How much flow to the carb? How much air gets in? Is the timing of all this correct? Then after you have chased down all these items, you have to go through the sub-items on each. With each new discovery, start it up and see the results. I'll keep thinking!
It hit me when you said you rebuilt the carb. the gasket for the cover that goes over the float bowl. The gasket kits dont contain the correct gasket for some models of carb. the gasket needs to be trimmed around where the float sits. I had the same problems you are describing it drove me nuts. The gasket wont let the float work right, some days it would work fine some days it wouldn't. Like you said it would run perfect just sitting there, i could dead rev it, fine, i could putt around with it, fine. I could open it up for a little while, fine. then when I would really get on it, it would cough and sputter and everything you described. until i slowed back down, then it would run again.
It was that top gasket(runs the whole way around the top of the carb). When i first rebuilt the carb, it worked great, but as time went on the gasket got stiff and staring keeping the float closed. I trimmed the gasket out to the edges of the float bowl, so that there was no material to hit the float, and have had no troubles since.
Hope this helps.
I'll check that. I think i kinda remember what your talking about. Somone also suggested the mixture adjustment could be too lean. Could this be possible? I pulled the spark plugs and they all 4 have a little white ash looking substance on them. But they look good. Does this say anything?
Could be. You should be getting a tan -light tan look on your plugs, not white. That is classic "lean". You can burn your pistons if you run like that.Did you change the jets on your carb, or needles? Because if you leave the stock jets and needles in it, it is usually close enough to run. And you never step more than two sizes in any direction when you change them.
Sound like someone tried to maximize economy and got carried away. You may have the solution.. :)
I left the jets alone, tho somone said i needed to lean it out because the egr is gone. Sounds like I might have hit the jackpot. I'll try the mixture adjustment and then the carb gasket. Thanks!
I raised the float a little on the carb and screwed the mixture adjustment screw in the base of the carb out one full turn. It did better i think but still wouldnt come above 60mph in 3rd gear (4500 rpm) then it started acting up, not anywhere near as bad but it still did. I think the float is too high now but im not sure. When looking down the throat of the carb and revving the motor (2500 to 3000 rpm id guess) i can see fuel spraying like a TBI unit. In a cone shape. Is that normal? I dont see any fuel spilling over the top, into the jets on the top of the carb body, or anything close the the gasket level so i think it is ok. I tested the spark with a tester from autozone tonite. It clamps on the block, and the plug or coil wire plugs into the other end. it allows you to adjust the distance for the spark to gap and tells you how far it needs to be set at for each application. For duaraspark its was like a 30mm or something like that... its got a lil guage in the bottom so you can tell where its at. Anyways i set it where it was supposed to be and from the coil wire it jumped a nice big blue spark about an inch or so long (however long 30mm is). Id say the coil is fine. I also bought 4 new bosch platnum spark plugs. I know alot of people say not to use them but i have AC delcos in now, and ive had alot of problems with delco plugs latly. The platnums always seem to work fine in 4 cylinders for me, but they zoop in V6's and V8's that ive tried them in. Kinda odd, anyways theyve always worked great in my 2.3s and the 2.5 gm that i had before so im going back to them. I'll keep you all informed. thx again for your help.
I too had this problem with my '74 when i got it. It turned out that the pickup "sock" in the tank was stopped up with rust. I could motor around all day in town, but as soon as I'd pulled 3-4 miles on the hwy it'd bog & pop. Have you checked the tank? Is it rusty inside? That'd also tell why you were ruining mech. fuel pumps. Rust has a way of building up in the lines & filters.
OK, you might find a little success with your adjustments, but remember your float adjustments are really for starting and idle. If you float is too low, it will die when you lift off the gas for a stop sign. The reservoir of fuel that is controlled by the float is for instantaneous response when you gas it, your accelerator pump is right there for that reason. And yes, when the accelerator pump is doing its job, it shoots out a cone shape, easy to atomize spray into the air stream of the intake.
And your coil sounds like it might be ok, but how you find out is let it warm up and see if you still get the blue spark. If it turn yellow, you know the coil is bad, under heat.
Keep messing with the float, and make sure your gaskets are all still good. Also,, one way to check plugs for high speed condition- clean your plugs, then warm up the car,, and take it out about as fast as it will go for several miles, then kill the ignition push your clutch in and let it coast to a stop. When you pull the plugs then, you will have a snapshot of their true high speed condition. Be sure and don't lock up the steering though when you turn off the engine.
Bosch plugs are good in Fords, and also Autolite, but stay away from Delco and Champion, they have a very short life in a Ford for some reason.
You said the car used to run great, so I'm guessing the carb jets are the same ones in it now as when it ran well, so you may have some debris in the jets, or a bent needle.
You have been very good at checking this all out, I know its about licked ;D keep us informed.
The cone shaped fuel was coming out of the venturi (the round thing in the middle of the barrel, atleast thats what i think is the venturi) and a steady stream was coming out of the nozzle for the accelerator pump. The cone shape and the stream from the pump nozzle are consistand while the speed is held consistant at 3000 rpm or so. It looks right, but im just trying to make sure that i havnt got a high float. I may recheck that tomorrow. The coil i tested right in autozones parking lot after i went in and bought the tester. Drove the car over there so it should have been hot. The carb jets i removed today and checked them for blockage. Everything seemed to be ok. Delco plugs is what i have in this thing and im not impressed so i am going back to the bosch's. Ive never rejetted the carb, even after removal of the EGR. So it should be the same as the factory installed. I also checked for blockage in/around the needle/seat by removing it and making sure it was all clean.
Hey I should have mentioned you can get the tiny numbers off the jets when you have them out next time,, and find out what size was originally in it. At this rate you might as well get some wingnuts for the carb and other pieces! You ought to know that carb really well by now. :embarrassed:
Everyone is going to have some suggestions for you, you just have to wade through them all. By that time you should have a new engine, carb, fuel system and electrical. :D
Yeah ive seen the little numbers before. i want to say they both said 22 on them but im thinking they were 32 and 36. Not sure.
I changed to bosch platnum spark plugs today and it made no difference. Does seem to idle smoother tho. Honestly i didnt check the fuel pressure, only the volume, when i checked on the pump. If the volume is fine can the presure still be low and will that cause the problem im having ?
I'd like to say that statement is true, but if you assume that, it might lead you astray. Adequate fuel at idle may fall way off at high speed. So it is best to know what your pressure is--a fuel pressure regulator might be a way to find out about your fuel pressure, see how it affect performance. They aren't too expensive and you can use them in other vehicles too. I really don't think that is your problem though. :-\
Here's a quick and dirty way to find out about your fuel tank cleanliness- if you have access to an air compressor, get a garden hose and a wet red mechanic rag. Put the hose in the gas tank to the bottom of the tank, cram the rag in around it to seal it up the best you can, and then stick the air hose nozzle in next to the rag, tightly as you can get it, and apply some air pressure. If you have a clean towel or white rag of some sort wrapped around the other end of the hose and in a catch bucket, you can get a real good idea about how clean the gas is. When you stop applying the air pressure, the fuel stops. Look and see if you have rust or debris particles floating around. DANGER!!! Take all precautions to keep ignition sources away from the are while you do this! Obviously, if your clean catch rag has debris in it, then do yourself a favor and have your tank boiled out. This method sure beats having to pull the tank if it isn't necessary.
I know theres all kinds of rust in the tank, i dump all kinds of rust out of the fuel filters every time i change them. I also find it in the bottom of the float bowl of the carb too (how it gets thru TWO fuel filters ill never know, but it does) altho its not thick enough in the bottom that it gets up into the small jets in the bottom/side of the float bowl. I really need a new tank, as mine is pushed up in the bottom....i guess somone backed into something and it hit the tank and bent the bottom of it in. Happened before i got the car. Anyways i guess it needs boiled out because i know theres tons of stuff in the tank. But, it doesnt seem to be restricting flow any, i mean the volume was great...even without the pump....it flowed really well by gravity. When i took the line loose from behind the pump (electic pump, close to the tank) to replace the filter that is attached to the rear of the pump. It flowed fuel like crazy. i had to put a plug in it because it wouldnt stop lol. I did have the tank off before, thinking i had a fuel line blockage only to find out everything was clear. I tried then to remove the sending unit to remove the sock but i had no sucess. I assume no one makes a new pinto fuel tank anymore? LOL. (i sure cant find one). If i have to use a fuel cell can i keep my fuel guage and keep it working? Anyone done this? Anways this is a little off topic since i think this has nothing to do with my problem. But its an idea, kinda spawned off my problem. Somone suggestd the pickup coil in the distributor and the stator/armature could be bad or out of adjustment. Does this sound like it could cause the problem?
You should just replace those, if you haven't done it in the last couple years. One thing you should do is check distributer play. Take the cap off and push on the shaft, back and forth, see if there is any play. If you get ANY play you rebuild or buy a re-built distributer. Just a tiny amount of movement can give bad fire. There is no allowance for movement at all.
I dont think that stuffs ever been replaced on mine. LOL. A new distributor would have all that new in it right? I checked for play on the distributor already, i dont beleive there was any front to back movement of the shaft but it would move up and down probably a 16th or an 8th of an inch. I'm thinking about a new distributor anyways. I think i looked and a new dizzy was like $46? Thats not too bad.
I don't know about up/down movement. Some may allowable? :-\ But I know there is a gas tank repair person out there, he's kind of expensive but guarantees his work--he' in Kentucky I believe. It's been a while since I got his info, if I find it I will forward it. Unless you have major rust-holes you probably need to get it boiled out, ask the guy who does it to stomp most of the dent out if he can. Some shops can take apart the tanks to do this repair. Unless you are going for a show car look!
I'm not going quite to the show car look on this car but i will make it really nice looking. I tested the fuel pressure today and it was 7 psi at the carburetor. Thats actually a hair on the high side. It needs only 4 to 6 psi.
I replaced the entire distributor and it ended my problem. Even brought back a little power. I had to try two distributors.....the first one was fine for a day or two...the second one has been in since the day after the first new one quit (i put the first one in on the 18th of january) and so far havnt had anymore problems. However. The gap between the armature and stator on my old distributor is very very close......the gap on the new one is a TON bigger on the old one, and the new one has a larger gap at the top than at the bottom (or maybe its the other way around, i forget now). Either way it doesnt look right. Should i be concerned with this? I mean, afterall it is what tells the coil to fire...i dont want my car to come in on the tow truck AGAIN because of this freggin distributor...
Well, if you dont get all that rust cleaned out of your fuel tank, you aren't going to have to worry about it. You already stated that you were finding peices of rust in the float bowl. What do you think that stuff does to your cylinder walls, and piston rings. Let alone your valve seats. :idea: