Engine Cutting out

[ratorrey]

Someone else has seen this I know it. Hopefully!!!

1990 Festiva, Auto with AC & 74000 mile. Driving down the road 45ish @ 2200rpm the engine will start too cut out,(would stall if I let it) if you feather the gas a little it will stay running and as long as you keep the rpm's up it appears to be OK. Engine is not overheating (according to the dash temp gauge) and the cooling fan comes on and off as it has ever since I have owned the car

I have swapped known good working parts from my 1993.

VAF
TPS

I have replaced with new.

Plugs
Cap/Rotor
PCV
Air Cleaner
Fuel Filter

Now the weird. If I unplug the Radiator Fan Contol Switch and let the fan run all the time the issue goes away

Thanx

Richard

[Movin]

No check engine light? Sounds like you may have bad grounds..on the engine
and the body. Bad grounds can make the o2 readings at the computer wrong.

[ratorrey]

No check engine light? Sounds like you may have bad grounds..on the engine
and the body. Bad grounds can make the o2 readings at the computer wrong.

Willing to check anything at this point.. Where is the groung you are referring to?? Why would the fan running all the time make it better??

Richard

[ratorrey]

No check engine light? Sounds like you may have bad grounds..on the engine
and the body. Bad grounds can make the o2 readings at the computer wrong.

Sorry, Correct no check engine light ever..

[FestYboy]

noticed you didn't change your wires, also look for carbon tracking arround the ign coil tower.

[ratorrey]

noticed you didn't change your wires, also look for carbon tracking arround the ign coil tower.

No I did not change my wires but poking arouind last night I noticed that the firing order was set for 1432. I checked my 93 and found it set at 1342 so I started researching what the true firing order should be(posted here and google)the majority say 1342 so I switched that. I replaced the cap a few weeks back and am pretty sure I did not swap 3 & 4. What really confuses me is that with 3 & 4 crossed it ran and I was still getting 35mpg. I have looked at the coil a couple times and saw nothing obvious but can say I may have looked right past it..

Thanx..

[Flyin4stroke]

Sounds like a ground to me.

Wiggle test the engine harness.

[Movin]

firing order wrong should produce results far different than you described.
Not sure exactly where the grounds are on the auto, I can look them up later
if need be, but find them and pull the bolt, clean the threads and mating
surfaces so that the computer has a clean playing field.

Your description sounds like it runs great then loses power until it would
even die if you didn't wiggle the throttle some causing fuel enrichment
then it will run some more..leading to why the computer is causing lean
out.

Also a slightly restricted cat can cause to much EGR with similar results
but no computer problems..and no light. Unplug the coolant temp and the
computer will turn on the fan and turn off EGR..Over heat logic.

[georgeb]

VAF would have beat itself to death with incorrect firing order.

[ratorrey]

Follow up

Ok. Car would not barely even idle last night on the way home, it was late I was tired so I had it towed. Went out this morning cranked it 2 or 3 times did not want to run. So I swapped the fuel pump. No luck. So I switched geard and started on electical.

Pulled (main)fuseable link plugged back in and the car starts. Runs 20 minutes and comes up to temp then starts cutting out even at idle. Now I start looking at grounds. Found 3 under the hood.

Negative cable at battery, frame and transmission.

Head to Passangers strut mount

Engine harness to metal plate close to where the radiator fan plug in.

I cleaned all and put it back together. It has been running in the driveway now for over an hour perfectly. I have more question.

Negative battery cable was on upside down and barely tight, was this my issue all along?

Who can tell me where to look for more grounds?

Does the ecm ground under the dash or on the firewall?

Richard

[watermellon]

what is an engine harness?
what's a VAF?

I'm not familiar with either one of these term. Is a VAF the same thing as a MAF?

[windy1]

fuel system?

Either a clogged cat , fuel filter or fuel pump sock, might cause your problem.

[DON SVO]

Good chance that your fusible links are grounding out. see if there is any bare wires on them, Personally I'd replace them with plug-in fuses just by proxy.

[windy1]

Either a clogged cat , fuel filter or fuel pump sock, might cause your problem.

SVO might be right.Adding : have you ever pulled all your wiring connections in engine bay. And cleaned them? Even add an xtra ground connection .

[miami man]

as i have said on this forum before years ago my 91 had a really bad idle sometimes and after replacing almost everything easy i accidently droped a wrench and it landed on the vaf meter box wiring and it changed the idle so i shook that wire up and down and that was the problem all along so now i shake wires to so if it is a problem...easy fix sometimes.