Engine choking?

[daveydalton]

Hey, guys, I'm no mechanic but was wondering if anyone has had the same problem and how to fix it.

I have a 93' Mustang LX 2.3, no turbo.
My car hits phases where the engine will start shaking like it's choked or something, and will accelerate extremely SLOW and the gears will jerk. And when I shut it off, I usually have to let it sit for several hours before it will crank back up, which it will run fine again. It randomly happens, I'm not sure what the cause of it is. Occasionally, if I drive it long enough and can keep it from dying, it will eventually work itself out of it? But while its doing this, if I put in reverse it will usually die, but if I put it in nuetral and the shaking will stop. A mechanic recently told me a bad fuel filter was probably sending bad gas through the engine and causing it to stammer so bad, so I replaced it and it ran great again for a couple of days and started to do the same thing again. If anyone could help, please let me know!

 

[Delray Dude]

Things to check:

coil packs. They are known to crap out and work sometimes and crappy at others. You have two coil packs - one could be completely dead and the other misfiring at times. easy way to confirm a dead coil pack is to unplug the connector on the front one and see if the engine runs. if so, plug it back in and unplug the back one. if you unplug one of the packs and get no fire - then the plugged in pack is bad.

IAC: Idle Air can be sticking and cause all sorts of idle problems.

DIS module. Does the tach do funky things when it's running like crap? The next thing to usually go is the DIS module. it is mounted on the front of the lower intake right behind the alternator. it has a plug in on the top and one on the bottom. 3 small nuts screw it in.

The computer: This could be your problem. I had very similiar symptoms and 1 had a dead pack and one that would misfire until it warmed up. replaced it and the thing ran great for a few months. then my DIS went out - the tach was reading like 2500 rpm at idle, and the thing ran crappy. replaced it and it ran fine for a few months. then i had issues similiar again, wouldn't run - or start then would start and run fine. thought it was filter - replaced (it was needed) did not solve the issue. replaced the fuel pressure regulator - wasn't problem. replaced the fuel pump. still not the problem. finally replaced the computer (found a great one in the junkyard) - replaced and the car came back to life. well over 15,000 miles ago.

other things it could be is a clogged IAC (Idle Air Control) or the EGR is sticking open. personally I'd block off the EGR tube and stop dumping crap back into the engine - also makes removing the upper intake much more easy.


once you figure it out - you should be golden. but check the packs 1st then the DIS. I think autozone will test the DIS for free - but i wouldn't trust them - i brought in two different 3G alternators and they said both were bad. i hooked both of them up to the engine and at idle they both produced 14.4 volts. I turned on the a/c, lights, wipers, stereo, my aftermarket fan, and they both were rock solid on 14.4. but if they say DIS is good then I'd suspect the computer is giving you your problem.

 

[Delray Dude]

also,

it is a good idea to kill the computer memory and let it re-learn itself. it does take a few drives for it to re-learn it's idle settings - it'll act like it wants to die and then will idle up.