PINTO CAR CLUB of AMERICA

Welcome to FordPinto.com, The home of the PCCA => General Help- Ask the Experts... => Topic started by: Jef_Leppard on July 26, 2017, 06:18:40 PM

Title: 2.3 Backfiring, no power
Post by: Jef_Leppard on July 26, 2017, 06:18:40 PM
Hoping I can get some help with a little problem!

My 77 wagon has a pretty basic 2300 motor with a Holly 500cfm carb.

The other day it suddenly started sounding different and I found that when I tried to accelerate, it would hesitate and backfire from the tailpipe.
I could barely limp it along and found that it couldn't get up enough power to go up an incline. Had to leave it and come back with a towtruck.
Anyway, I've been trying to solve this problem with no luck.

So far I have replaced the plugs and wires. Checked the cap and rotor... they seem okay.
I took off the carb and did a bit of disassembly and cleaning. Not thorough but it actually seemed quite clean inside. I can see that fuel is squirting inside.
Checked the timing belt. It didn't jump.
Disconnected the fuel lines and blew through them with an air compressor.

I'm not sure what to try next.  Any help would be appreciated!
Title: Re: 2.3 Backfiring, no power
Post by: r4pinto on July 26, 2017, 06:23:07 PM
How is your fuel output? May want to do a volume test to see if it's getting enough fuel.

Title: Re: 2.3 Backfiring, no power
Post by: TIGGER on July 26, 2017, 09:16:16 PM
Maybe check your ignition because in my experience tail pipe backfires are usually due to ignition.  Years ago, I had an ignition module go bad and the car would hesitate, buck, and backfire when driving but would idle fine.  I chased my tail for a couple weeks and finally figured it out when I had a dwell meter connected.  I bumped the throttle and dwell was all over the place when the car would come down to idle and then it would stabilize again.  I replaced the module and things were good.  Hopefully you figure it out.
Title: Re: 2.3 Backfiring, no power
Post by: dick1172762 on July 27, 2017, 01:36:11 PM
Timing belt may have slipped a tooth or two.
Title: Re: 2.3 Backfiring, no power
Post by: one2.34me on July 27, 2017, 02:55:16 PM

This'll sound ridiculous, but it happened to me. Way back when,  I was driving my 2.3, 1979 Pinto home from work, when I hit a hill the engine would shut down and barely crawl. Down the hill it ran fine. It turns out that when the tank got to a quarter full and I went up an incline something was floating in the tank that would block the fuel line. From that point on, I didn't let the fuel get to a quarter of a tank. I never had another problem with it.


No laughing, it really happened.
Title: Re: 2.3 Backfiring, no power
Post by: dick1172762 on July 27, 2017, 03:09:44 PM
Had that too but with a battery. My driveway was down hill so the parked cars were at an angle. Every day I had to jump the battery on my car, but when I would get off work it would start right up. The problem? Low acid in the battery causing no connection on a hill. Toped off the battery and all was ok.
Title: Re: 2.3 Backfiring, no power
Post by: Jef_Leppard on July 27, 2017, 03:14:03 PM
Thanks for the help. Being able to go to a place like this and brainstorm is really valuable for keeping this old car running, especially with my somewhat limited mechanical experience.

Actually Tigger's suggestion to look at the ignition gave me the idea to recheck the distributor and it was looking like maybe the cap was more beat than I thought when I first checked.

Surprisingly my local O'Reilley's had one dusty distributor cap left on a shelf and even a rotor to go with it.  So $14.00 later, vroom!  Back on the road.

Anyway, feel dumb for overlooking something like that but glad that's all there was to deal with. Thanks again!
Title: Re: 2.3 Backfiring, no power
Post by: dick1172762 on July 27, 2017, 03:48:33 PM
Help on a Pinto problem is what we're here for among other Pinto things.
Title: Re: 2.3 Backfiring, no power
Post by: one2.34me on July 28, 2017, 01:41:52 PM

 Glad it was a simple inexpensive fix.
Title: Re: 2.3 Backfiring, no power
Post by: dick1172762 on July 28, 2017, 02:47:12 PM
Jack! New picture of your Pinto looks GREAT! Nice and low like a Pinto should be. Keep up the good work.
Title: Re: 2.3 Backfiring, no power
Post by: Billnparts on July 29, 2017, 02:28:20 AM
Swap out the ignition box.


Sent from my iPad using Tapatalk
Title: Re: 2.3 Backfiring, no power
Post by: one2.34me on July 29, 2017, 01:03:30 PM
Jack! New picture of your Pinto looks GREAT! Nice and low like a Pinto should be. Keep up the good work.

Thanks Dick, I appreciate it! A photographer was taking pics as cars were idling by to get into this years Fabulous Fords Forever in Buena Park. Needs some Aero wheels with less offset and to get the air dam closer to the pavement.
Title: Re: 2.3 Backfiring, no power
Post by: 65ShelbyClone on July 29, 2017, 02:50:42 PM
Is there anywhere to find more info or photos on your car? I like the stance and am shopping for Aero or Bassett wheels now, just need to figure out what is going to fit.
Title: Re: 2.3 Backfiring, no power
Post by: dick1172762 on July 29, 2017, 03:05:38 PM
Jack has built a very nice Pinto street racer while watching were the $$$$ should be spent. GREAT car.
Title: Re: 2.3 Backfiring, no power
Post by: one2.34me on July 30, 2017, 04:08:36 PM

Thanks for the compliments, this is basically what I've done to the suspension,

Tires -BFG Sportcomp2's  195/55-15
Wheels- Mustang 10 hole, 4x4.25", 15x7" (getting these was a big mistake, it took 5/16th spacers and a lot of trimming to clear the wheels from the upper A frames, which are now rubbing again. Looking at 4x4.25", 15x7", 3" back space Aero wheels)

Rear,
Rock Auto-YBKG5514 Gas-A-Just shocks
1" lowering block
Addco  #345 Rear sway bar kit

Front,
Rock Auto-YBKG4511 Gas-A-Just shocks
Spring shop cut coils approximately 2", Still didn't look low enough, so I cut another half coil.
Addco  #184 Front sway bar kit
5/16" wheel spacers.


I'm not sure what the issue was, but both sway bar kits required a lot of cutting and fabricating to get the sway bars to mount to the front and rear chassis and A frames.
Title: Re: 2.3 Backfiring, no power
Post by: Jef_Leppard on August 09, 2017, 04:45:01 PM
So I thought this was case closed but NOPE!

After replacing the distributor cap and rotor, it ran normal for two days, including an 80 mile drive. Then I noticed it seemed to be starting harder, taking longer cranking to get it to fire up and then once started, it would just barely idle.  Got stranded in a parking lot again. I was able to advance the timing enough to limp it slowly home but again, if I tried to speed up it would stumble and almost stall out.

Now I'm wondering if maybe replacing the cap and rotor really didn't do anything but rather it was some intermittent electrical problem that randomly went away at the time?

I didn't have much in the way of testing equipment but I thought to run a timing light gun connected to each of the cables. I found that all of them had very intermittent spark.

I replaced the coil and also the ignition control module but then it seemed like it was actually getting worse. I tried replacing the connectors on the coil harness and still no improvement.

I tried disconnecting the tachometer connector inside the dash because it had long been acting weird with a bouncing needle... wondered if maybe that wiring could be messing with it somehow. No luck.

From there, I don't know where to go next. I don't understand the electrical system enough to not feel like I might just create new problems if I start digging around. Actually, I'm worried now that I already may have, messing with the coil connectors and tach.  It currently has no spark at all.  It's been at a garage for a couple days and they haven't been able to figure it out either. 

Help??
Title: Re: 2.3 Backfiring, no power
Post by: Pintosopher on August 09, 2017, 07:44:38 PM
My Two cents..
 Have you considered the Intermediate shaft that drives the Distributor. If the Shaft has cracked and sheared then the rotor would not rotate consistently. Likewise the gear on the bottom of the Distributor that meshes with the Intermediate shaft may have worked loose or stripped the teeth, and again , lost consistent ignition timing. This would also affect the oil pump drive too, and that is critical ,even if it did run enough to show some oil pressure. Worth crossing off the checklist before launching into electrical diagnosis.

 Pintosopher... Pennies of concern where Dollars fear to tread
Title: Re: 2.3 Backfiring, no power
Post by: Jef_Leppard on August 09, 2017, 07:51:39 PM
Yeah I actually have had what you're talking about happen before.

With this, there is no spark happening at the coil. It's a new coil and I replaced the control module with it.  It seems like there is no electric reaching the coil....
Title: Re: 2.3 Backfiring, no power
Post by: TIGGER on August 10, 2017, 02:58:07 PM
Maybe try and run power from the pos battery terminal to the positive side of the coil and see if it fires.  That would tell you if you had an electrical problem VS a mechanical one.
Title: Re: 2.3 Backfiring, no power
Post by: r4pinto on August 11, 2017, 08:23:51 AM
One suggestion I have. Get a spark tester from the auto parts store. They hook in line of the spark plug wire. Start the car and observe the spark if you're able to get it started. You can then see what it looks like color wise to give an idea of what is going on. It will also tell you if the wires are even firing. Have someone crank the car or use a remote starter at the solenoid. Just make sure it's in neutral if manual. That'll give you an idea of the kind of spark and if a cylinder isn't firing.

Also go ahead and take the module to the auto parts store and have them test it. Just because it's a new part doesn't mean it's not bad. Check the coil resistance as well. I don't recall the specs but go from terminal to terminal on the coil, then terminal to the tower the wire plugs in to. It's possible the coil or module have gone bad.

Of course double check your cam timing. If it's off, even one tooth it can give issues.
Title: Re: 2.3 Backfiring, no power
Post by: dick1172762 on August 13, 2017, 11:52:55 AM
Try pulling one of the plug wires off while it running. Look at the color of the spark. It should be a very nice blue color. If the color is white, you do have something wrong in your electric system. Most likely the coil.