I am finally getting around to getting to tuning up my motor for the first time. I have a 71 Pinto with a stock 2000cc motor (at least I am pretty sure it is stock).
Anyway, for the first time today I adjusted my valves. Most of them were too tight (according to my do-it-yourself pinto care book). Now i have more alve noise but a smoother runnign engine, but I still have a noticeable vibration in the motor.
This is my first 2000cc motor so I don't know what is "normal". Should I expect some valvetrain noise and vibration from the motor? Would a video help?
gee i dont know that one i always ask my dad or pintony
What did you set the valve lash at? I always ran mine at .010" on the intake and exhaust, but that was an aftermarket racing cam. IIRC the stock spec was .010" intake and .012" exhaust. At any rate there should be almost no valvetrain noise, and what is there should be uniform. In other words, no tap-tap-tap noises. Did you happen to pop the rockers off and check for wear? What about the cam lobes? They should be perfectly smooth, no grooves or scratch marks.
As far as the vibration, do you mean when it is idling the engine is shaking? That could be carb adjustment out of wack. If it is really bad you could have a burnt valve. A compression test could be in order. And yes, a video might help a lot.
I set the valves to the stock specs- .008 exhaust and .010 intake. The valvetrain noise is definitely not uniform and is very audible. The cam lobes looked okay, but I wasn't paying close attention.
The motor is actually shaking at idle. Adjusting the curb idle screw and the idle speed does significantly affect it.
This morning, I adjusted the float in order to get the car running again. I thought the float level was wrong because no gas was getting to the carb, but it turned out the fuel line had a clog. Once I got the car running again I learned that I had misadjusted the float and the car ran for a few second then stalled out. I readjusted the float and the car ran, but roughly.
I discovered that the curb idle mixture screw was 2.5 turns out. I turned it back in to 3/8 of a turn out and the car idle much better, but still has a definite shake at idle.
I will redjust the valves tomorrow, double check the float setting, and do a compression check.
Here are some videos of the car.
The first is cold startup and ile, the next few are idle where I tried to show the vibration and the noise, and the last is idle and revving and the car dying (with a brief shot of me at the end). :'( Never died when I revved it before....
I think I need to really get into the carb and make sure all adjustments are correct.
Cold start:
(http://img.photobucket.com/albums/v484/slantsixgoon/Pinto/th_coldstart.jpg) (http://smg.photobucket.com/albums/v484/slantsixgoon/Pinto/?action=view¤t=coldstart.flv)
Idle 1:
(http://img.photobucket.com/albums/v484/slantsixgoon/Pinto/th_idle1.jpg) (http://smg.photobucket.com/albums/v484/slantsixgoon/Pinto/?action=view¤t=idle1.flv)
Idle 2:
(http://img.photobucket.com/albums/v484/slantsixgoon/Pinto/th_idle2.jpg) (http://smg.photobucket.com/albums/v484/slantsixgoon/Pinto/?action=view¤t=idle2.flv)
Revving:
(http://img.photobucket.com/albums/v484/slantsixgoon/Pinto/th_revanddie.jpg) (http://smg.photobucket.com/albums/v484/slantsixgoon/Pinto/?action=view¤t=revanddie.flv)
The video quality is pretty crappy so you can't see how it shakes. I tried to zoom in on the clea gas filter so you can see the gas jiggling in there and get an idea of the vibration.
It's possible you have a vacuum leak. Check all of your lines to the carb and intake and make sure there are no uncapped ports. Take some carb cleaner and spray around the base of the carb and where the intake bolts to the head. If it picks up speed or smooths out there is the leak. Take the filter off and spray a fine mist directly into the carb. It should try to choke out, (adding more fuel should make it flood out) if it smooths out the carb could be way lean. If you still have a points dist. check and adjust the points (.025" i think is the spec) and set the base timing. I always ran mine at 10* BTDC. The 5200 carbs are decent carbs but the best thing I ever did to my stock 2.0 was to put an adaptor on the stock intake and use a Holley 350 2bbl. It ran way better, really increased the throttle response and power, and believe it or not, got better MPG.
Oh yea, when you check the valve lash again, look closely at the cam lobes. If any show signs of wear, pop the rocker off and I'll bet it has a nasty groove worn in it. I have taken emory cloth and polished the lobe and put on a new rocker and it was OK. To get the rocker off, make sure the lobe is sticking straight up, take the mousetrap spring off, put a large screwdriver under it from the adjustment side and pry it off. To put it back on, put it on as far as it will go from the valve spring side and wack it with a small hammer. It will pop right back on.
Be careful when you set the valves. The adjustment tends to change when you tighten the lock nut. It's easier with two people, one to use the feeler gauge and the other to work the wrenches to hold the adjustment and tighten the lock nut. BTW, you are taking the mousetrap springs off the rocker when checking and adjusting lash, right?
Quote from: 71pintoracer on September 20, 2008, 09:32:00 AM
It's possible you have a vacuum leak. Check all of your lines to the carb and intake and make sure there are no uncapped ports. Take some carb cleaner and spray around the base of the carb and where the intake bolts to the head. If it picks up speed or smooths out there is the leak. Take the filter off and spray a fine mist directly into the carb. It should try to choke out, (adding more fuel should make it flood out) if it smooths out the carb could be way lean.
I will check for a vacuum leak. I do know that if I turn the idle mixture screw much beyond 3/8 of a turn out that the engine starts to idle very rough. There is one uncapped port right next to the idle mixture screw.
Quote from: 71pintoracer on September 20, 2008, 09:32:00 AMIf you still have a points dist. check and adjust the points (.025" i think is the spec) and set the base timing. I always ran mine at 10* BTDC.
I switched out the points to Pertronix and I am running a Mallory Voltsmaster coil. Pluggs are gapped to .045 (and when I pulled the plugs they were very sooty). Timing is set to 6BTDC, as per factory specs.
Quote from: 71pintoracer on September 20, 2008, 09:32:00 AMThe 5200 carbs are decent carbs but the best thing I ever did to my stock 2.0 was to put an adaptor on the stock intake and use a Holley 350 2bbl. It ran way better, really increased the throttle response and power, and believe it or not, got better MPG.
For now, I want to keep the staged two barrel and get an Offy dual port intake. I am trying to maximize fuel efficiency. I may start playing with other carbs later, but I want to get the stock system working right first.
Quote from: 71pintoracer on September 20, 2008, 09:32:00 AMOh yea, when you check the valve lash again, look closely at the cam lobes. If any show signs of wear, pop the rocker off and I'll bet it has a nasty groove worn in it. I have taken emory cloth and polished the lobe and put on a new rocker and it was OK. To get the rocker off, make sure the lobe is sticking straight up, take the mousetrap spring off, put a large screwdriver under it from the adjustment side and pry it off. To put it back on, put it on as far as it will go from the valve spring side and wack it with a small hammer. It will pop right back on.
Be careful when you set the valves. The adjustment tends to change when you tighten the lock nut. It's easier with two people, one to use the feeler gauge and the other to work the wrenches to hold the adjustment and tighten the lock nut. BTW, you are taking the mousetrap springs off the rocker when checking and adjusting lash, right?
Nope, I am not taking the springs off the rockers. I followed the procedure given in the "How to maintain your Pinto" book I found in the glove box. I just turn the motor by hand until the correct lobe was pointed down, then adjusted the correct valves. I have adjust valves on a slant six many times before, but this is my first time working on a 2000cc. I have a bunch of learning to do.
Thanks for the help!
you might check the plug wires too.
Plug wires are new 7mm high-suppression wires. The previous owner had them installed.
Problem solved! I went out tonight and readjusted the valves. All were very loose. I think I adjusted the valves wrong and I think that the valves should be adjusted when the motor is cold. Last night I adjusted the valves when the motor was hot, and I think the clearances were off.
It is running much quieter and smoother now. :afro:
Glad to hear you got it straightened out. I should have mentioned to adjust them cold!! BTW, I looked at my service manual and it shows the springs left on. I don't think it matters one way or the other, I removed them all and then put them back on one by one as I adjusted each valve. That way I could keep track of which ones were done so I didn't miss any.
I tried taking the springs off on a couple valves, but one rocker fell off and the springs kept getting in the way. So I ended up leaving them all on. Also, the manual says the valves can be set with the motor hot or cold, but obviously cold is preferred.
Thanks for the tips!