Random stumble from idle to ~3000RPM 1994 ATX 3.2 SOLVED!!!!

[b1lk1]

OK, just got this car from the original owner. 211,000KM on it, this guy did not have any receipts or idea what services took place and when. He did keep it up, but it is in obvious need of love.

Has a random miss/stumble, have to really push the pedal to get it to come to life, but when it does it is very strong. Idle is off and on wonky too. I'm gonna clean the MAF, throttle body and swap in some new plugs, anything I'm overlooking? I also plan on doing the big service on the timing belt very very soon, owner is not even sure he ever had it done.

 

[msteiny]

your off to a good start. Check for vacuum leaks as well, like the intake couplers. They get brittle over time.

 

[3d914]

Ditto on the leaks. Anything with rubber, including injector seals, is a candidate to look at. When you pull the plugs look for signs of oil leaks from valve seals. If you can do a compression check that will help you evaluate the motor further.

And have fun

 

[zblackbeast]

Check your spark plugs too. They could be fouling out. The higher the rev and harder the throttle load the more intense the spark will be which is typically when it will fire.. From my experience when mine was backfiring and sputtering and running like dog shit until i buried my foot, it was the plugs. Use autolite 3924's.

 

[Carmievg]

I'd bet you half a donut that when you pull your plug wires you'll find a bunch of oil in the wells around the plugs. That issue had me scratching my head for quite a while. Tried all the usual suspects; Bad gas, dirty air or fuel filter, throttle body dirt, TPS, all kinds of things. I resisted changing the plugs because the three on the back side can be a mite annoying to get at. Decided one day screw it, I've tried everything else, must do the plugs. The two inches of oil in the wells was indeed shorting the plugs out. Cleaned the oil from the three front wells with a shop vac and some compressed air (a little squirt of brake cleaner to thin the oil seemed to have helped), and just for giggles spun the motor. Worked like a champ. Ended up putting the old plugs back in. They were fine.

I tend to get a bit long-winded, and for that I apologize. But that's probably what's making your car run like crap in the low RPM range.

 

[rubydist]

check your codes first.

before you do anything, check your codes.

always check the codes so you are not guessing at the problems.

get the message?



let us know what codes you have and we'll steer you in the right direction.

 

[b1lk1]

I get the feeling I need to check for codes, lol.

Funny thing you say that, I spent 10 minutes looking for the OBD port under the dash before I remembered that there is no such creature in this car.

 

[b1lk1]

No code reading yet, but 3 spark plug tubes full of oil were found. Cleaned them out, runs mint, only problem is that the plug wires have been ruined and eventually pop out. Time for some gasket work and a tune up. Gotta get this thing to pass the emissions testing, already failed once.

 

[rubydist]

it will fail from the miss due to the oil in the plug wells and the resulting bad plug and wire - they will short to the head rather than fire.

BUT, do not change plugs and wires without changing valve cover gaskets, because the oil will return and ruin the new plugs and wires.

 

[jimtash]

Put RTV on the spark plug tube gaskets as an extra precaution. Never had any leak since doing that.

 

[3d914]

Put RTV on the spark plug tube gaskets as an extra precaution. Never had any leak since doing that.

Ditto. Grey RTV is my best oil-leak prevention buddy

 

[sho'noff]

Ditto. Grey RTV is my best oil-leak prevention buddy

good idea, shucks will want a hundred dollars for the valve cover gasket and spark plug oil seals.

 

[jimtash]

Rockauto is your firend. So is Advance. Excellent deals if you search around and use their coupons.

 

[b1lk1]

Yeah, back 3 holes full of oil too. I'm changing just the plugs and wires just to get my emissions testing done, Then I can get my plate sticker, then I am doing the valve cover gaskets, timing belt and whatever else needs doing. I am gonna do a trans flush, new rad hoses and a coolant flush. This car is a complete money pit, not sure why I am rescuing it, but I do really like the car.

It needs both rockers, part of the passenger rear quarter has a hole, moonroof does not work, needs full paint...

Gonna be into this thing for an easy $5K before long, oh well, I hate watching cars like this go to the yard. It runs SO beautiful, it is worth the effort.

 

[b1lk1]

OK, having failed the second Etest even worse than the first after the tuneup, I knew I was pooched. SOOOOoooo, pulled codes:

172, 173, 176, 332, 336, 337 and 543

Also used the scantool to get a live datastream, it was amazing to see how much data you can get out of this car. Anyhow, found the rear O2 was not doing anything, fuel trims were in outerspace, running pig rich. 2 new O2 sensors and a cleaning of the EGR to free it up and it is seemingly running very good. All misses and such gone, gonna try one more time to pass the etest, but now with functioning O2 sensors and an EGR that does not hang up.

I realize what the other codes are pointing towards, but I hope I got it nailed for the Etest.

PS: Also smoked the intake for leaks, it is 100%.

 

[SHOdded]

Nothing like smoker's lung to make you wanna punch yourself. Good luck!

 

[sho'noff]

Maybe the fuel injection needs to be cleared out, go to shucks and find some of the cleaner that you pour in the gas tank and run it through with a half tank.

 

[3d914]

OK, having failed the second Etest even worse than the first after the tuneup, I knew I was pooched. SOOOOoooo, pulled codes:

172, 173, 176, 332, 336, 337 and 543

Also used the scantool to get a live datastream, it was amazing to see how much data you can get out of this car. Anyhow, found the rear O2 was not doing anything, fuel trims were in outerspace, running pig rich. 2 new O2 sensors and a cleaning of the EGR to free it up and it is seemingly running very good. All misses and such gone, gonna try one more time to pass the etest, but now with functioning O2 sensors and an EGR that does not hang up.

I realize what the other codes are pointing towards, but I hope I got it nailed for the Etest.

PS: Also smoked the intake for leaks, it is 100%.

Making progress. Congrats! Can you tell me more about the scan tool? Where and how might one acquire, borrow, steal one?

 

[sho'noff]

your local auto parts store will have a ford code reader for the non obd vehicles get the one with the digital screen, there is nothing worse than counting the blinking light.

 

[b1lk1]

I used an OTC Genesis shop tool, probably a $2-3K tool, not something to buy just to have it. Lucky for me I am a mechanic and my buddy has a pretty well equipped shop so the scanner and smoker were free to use.

As for the injectors, I have run a full bottle of Seafoam through the tank.

I just gave it a quick cold start this morning, still seems to be cooperating, it drove beautifully for a few hours last night, all part throttle issues were gone, idle was smooth as glass and rock steady, did not hunt once.

I will say this, the best possible advice IS to scan first, throw parts second. I knew my car needed a tuneup no matter what so that was a no brainer, but I could have started wasting good money if I weren't careful.

I'll report back if it passes the Etest today.