Ok first of all i did do a search and most of them didnt give me an answer and not the same symptoms..
My 91 rs 3.1 falls on its face with WOT and even 1/4 throttle.. i have to drive like a grandma just to go but still wont get over 30mph.. First it did it only after bout 30 min. of driving and now does it all the time.. I push the throttle anywhere further than 1/4 and the car stumbles untill i let off.
If i hold the gas down in gear and even N or P then i get a backfire through the intake . And during the whole time the car will hit 4500 rpm then drop to 1500 till i let off.. I just replaced the wires, plugs, cap and rotor and still the same thing .. The plugs were white and the cap had white on all the contacts. Not sure what this means but can anyone shine a little light on the matter.. This is my 3rd car in a month, The others just died and I gave up which is about the same for the camaro

 

Replace fuel filter and get your catalytic converter checked. Sounds like a fuel issue.

 

Fbod nailed it.

What is happening is your catalytic convertor is busted inside (honey comb is twisted up sideways). When this is getting hot, it is expanding and plugging off the exit port of the convertor (to the tail pipe) and is restricting airlow out of the engine (air doesn't flow out will also prevent air flowing in) This is why your car starts to rev and then plugs up and falls on its face. The ol potato in the tail pipe syndrome. Check that first definately, you most likely need to pull it and get a new one, or just gut the remaining broken honeycomb ceramic out of it to regain flow as long as you do not lve in the great BS state of Calif where cats are required for smog checks.

 

Thanks for the replies.. im going to take it now to get a new cat installed and ill i'll let ya'll know what happeneds.. thanks again

 

time for a tune up. probably bad wires. Dont matter if they are newer, change em.

 

The convertor might be it; but I don't think it'd allow him to be okay if he starts off like grandma, and cause him to stall. It'll be interesting to hear the results tho- I've only driven in ONE f-body with a clogged cat- the car would steadily move forward at the same RPM no matter how far the gas pedal was pushed down. It was like the car had one speed, "forward", and that was it.

Glad to hear you checked the plugs. The white stuff (ash deposits) could be oil burning, or show excessive use of cleaners (like injector cleaner or tuneup gas additives)- but on plugs, those ash deposits shouldn't affect ignition that badly. You could probably clean them, re-gap to 0.045, and put them back in.

On the other hand, the white stuff on the cap and rotor contacts is called carbon tracking; enough of a buildup will cause a bad misfire! I had that happen once to me.

Like Gumby hinted at, after the catalytic convertor is checked/repaired, you basically should run thru the major tuneup list (see https://www.thirdgen.org/techbb2/sho...hreadid=162251 ) and first, concentrate on your ignition parts - and don't forget the timing!! (A lot of people ignore the timing.)

One more thing- you mentioned two other f-bodies dying on you recently. Was this '91 sitting for a lonnng time? If it was, the gas might've just gone bad. My car wouldn't start up after it was stting for about a month! The tank was almost empty tho (nearly on "E").

 

Is it still doing it???

Next time it happens, turn the car right off and then back on. If it run fine after that, its fixed.

Before you leave next time turn your car on and off a time or two before it fires. I bet it will never happen again.

 

Ok this is Some major .. i Said fck it and took it to a shop close to my house.. ASE certified machanics (sp?) told me that i had a bad ignition coil and a stopped up cat.. So i replace the ignition coil and nothing changed.. Then i took the Cat completely off, which was stopped up. but still did nothing at all.. So now im down to replacing in the last week, Plugs,Wires, cap, rotor, coil, and cat.. Im completely broke now and still have no car.. It's not throwning any codes at all.. And the car wasnt sitting at all so no bad gas. Also i've been putting b-12 in the gas to clean the injectors and stuff.. But the "ASE" people timed it,checked fuel pressure and all that good stuff.. So now im back to point one.

 

tps?

 

still doing it???

Did ya try turning the key on and off a few time befor you start it???

Give it a try.

is your colum lose???

 

i tried what you said gumby but it was a no go.. the colum is not loose at all.. i guess i could go get a new tps.. hell everything else is getting replaced

 

Sorry to hear it is still giving you problems, but I suggested above to check the cat first, not necessarily replace it, just inspect if it was broken up and loose internally. Did the shop you took it to to "replace" it show you the old cat they took off to verify it was bad? Was the new one needed or did they just tell you that and not show you the part. Always demand that you see the bad parts that were replaced on your car ANYTIME you have work performed.

Now, with what you just stated in your last post-
"ASE certified machanics (sp?) told me that i had a bad ignition coil and a stopped up cat.. So i replace the ignition coil and nothing changed."

Did he proform the work? or did he just tell you what he thought and them you took it upon yourself to change things?

Reason why I ask is if he did it, the car would not leave the shop unless you paid for the work performed and no one in their right mind would pay for worked performed to get a car running when it still didn't run. This leads me to believe you took it upon yourself to change the ignition coil. Problem here is- I really don't think the mechanic told you "ignition coil", he probably said to you the "pick-up coil was bad and you just thought "oh, the coil, I can do that"

Sorry to say to you that it sounded that you possibly had multiple problems with the car and I was trying to help you sort them out one thing at a time by checking the cat first (I am still banking that it was definately bad and causing at least part of the problem when the car would fall on its face after 30 mins.

The next thing after verifying the cat was flowing (not broken up and loose inside) is to pull the distributor out of the car and have a shop rebuild the "Pick-up Coil"- housed inside the distributor cap. Heat produced from the straining motor propably lilled the pickup coil (This in NOT the ignition coil- 2 different things) That being bad will cause the car to "feel" like it isn't getting fuel, backfire ocationally, and just flat out notclimb much above an idle rpm at all. When it finally just goes, the timing will be so far out of wack from the pick-up coil not reading correctly the cylinder firing points that the car will eventually not even stay running when starting it.

The pick-up coil is what indicates cylinder firing points and is the trigger for the igniton module. This is your major timing advance indicator when the engine revs and it is not functioning properly.

 

"Did the shop you took it to to "replace" it show you the old cat they took off to verify it was bad? Was the new one needed or did they just tell you that and not show you the part. "

They said the cat was clogged so i replaced it myself.. But i just cut the cat out and replaced it with some expandable pipe for now since i dont have the money for a new cat right now.


"Now, with what you just stated in your last post-
"ASE certified machanics (sp?) told me that i had a bad ignition coil and a stopped up cat.. So i replace the ignition coil and nothing changed."

Did he proform the work? or did he just tell you what he thought and them you took it upon yourself to change things?"

He told me that the ignition coil was really weak and needed to be replaced so i replaced it after i paid for the diagnosis...
So i guess ill take the ditrib. and go get it rebuilt.. more money i dont have.. Thanks for the reply though

 

mine backfired through the nitake when my mas air flow sensor was dirty, i cleared it out with compressd air. i also had this symptom when my timing was off

 

well i believe 91-92 cmaros dont have a MAF.. And the place i took it to retimed it

 

damn im out of solutions

 

I explained the very high probability of what it is in my last post- I am giving this recommendation based on first hand experience. I have had both problems of-
1)a cat plugging up and killing any power to the car after it gets heated for about 10-30 mins of driving (Based on freeway or surface street driving. ex; alot of idling or not will change the time frame due to exhaust heat levels). I have had this happen a few times on different vehicles.

2) the radical power loss and stumbling when pressing the gas pedal above idle raising rpm levels and resuling in a fluctuation lag and an occational intermittent backfire. An ignition module will react close to the same but will backfire much more and still run fairly decent at times until it just flat out dies. The pick-up coil will react like the engine is starving of fuel when you try and raise the rpms. It will fell like the timming is jumping all over the place and run very erratic with no power. I have had this also happen to me twice, once on two different cars.

 

ok thanks for all the comments.. and vsixtoy i already did #1, i just cut the cat out and i've done half of #2. I replace the ignition coil yesterday and im in the middle of the pick-up coil. i pulled out the distrib. and i lost the damn bolt. I've already replced the pick-up coil but cant put the distributor back in untill i find or buy another bolt.. but we shall see what the outcome is tomorrow

 

ok so i just got done installing the distributor and nothing has changed.. Still does the exact same thing.. So now i replaced:

Cap
Rotor
Wires
Plugs
Ignition coil
Pick-up Coil

But now it seems to be back firing alot more than previous..And its still backfiring through the intake.. Im all out of ideas. Do ya'll have any more ideas on what it could be?

 

Do you have the capability to take a picture of your distributor assembly without the cap on? I would be great if I could see the condition of the contact points and the assembly in general.

Is it possible the guys timed your car wrong and moved things way out of wack trying to correct the bad timing reading.

You are going to have to static time the motor. Put the #1 cylinder on TDC (Make sure its not 360* off and sitting on #4). Now move the crank to 10* on the timing mark.

Next mark the base of the distributor with a marking pen just under tthe #1 plug wire on the cap so you have a reference point towards #1 without the cap on. Then insert the distributor into the block all the way making sure the oilpump gear is properly mated to the distributor shaft end. Now with the rotor on the shaft, spin the base around and tighten it down with the rotor pointing directly at the mark on the base- Its timed.

Put the cap on with plugwires attached properly and all other connections, Then connect the battery and try it. lets see what you have at that point. There ar times when things are messed with that aren't the problem to begin with and then everything can get out of wack and be misleading.

Also, when you had the distributor out for rebuilding, did you bother having the module tested- almost any store or mechanic will do this free standard practice when rebuilding the distributor- you didn't mention if that was checked in the rebuild process.

 

I want to add by repeating again to you that you have a high probability of having multiple problems and that I am trying to weed them out for you without costing you an arm and a leg.

The problem with most do it yourselvers on a budget is (please take no offence, everyone of us is either the same boat, or at least have been it that same position at one time in life) that the car is generally being drivin as far as it can possibly go until it dies. Most often always showing codes or sensor problems that are just ignored as long as the car still just gets you where you have to go.

Now when multiple things are bad, and even professional hook things up to inspect the system on a diagnostic, even they can not accurately pinpoint the exact problem if many things have been neglected. This is why I above stated to you to "take the distributor to a shop and have them rebuild it". They have the electronics to verify of that particlular part is in 100%working order and is rebuilt properly. I have done mechanical work on my own vehicles for 25years- however, there are certain things when it comes to electric componants that you should always have professionally done on a distributor wheel and verified. I have many many times in my life bought a brand new part that was bad from the get go even. They could check the old parts also beforehand and verify if it needed replacing, or maybe a contact point of two were bent etc... and if the module was insulated properly on the last install, slop in the housing too much, there is alot of little things that if you are not savy to can be overlooked. Sometimes you just HAVE to break down and have a shop do it for you or it will cost you more in the long run than if they inspected things one by one first.

The fact that you say now the car is backfiring more than before tells me that this pick-up coil if replaced correctly did cure part of the problem because it changed the characteristics of what the car was doing even more if everything was put back exactly the same, but with a new pickup coil- See my point?

I still believe that you must have originally had a cat plugging on you, and as you continued to ry and use the car the engine bay heat got sohot from the exhaust (from plugged cat retaining heat in the exhuast manifold) that you have overheated and burned up many of you electronics in your ignition. Your O2 could even be fried, but a very slim possibilty- this the car would still run, just not efficiently.

I still suggest to take the distributor back out and take it to a professional to have it inspected- but only after you try to static time the motor first to rule that out.

 

ok one quic question before i do all of that.. ok the contact points your talking about is the star shape thats under the cap right? 6 points? is every point suppost to barely touch or come close.. because i noticed when i took it out that 3 points came very close to touch(if not touch) but yet the other 3 had a gap in them

 

My Camaro did all that when the timing was off. Make sure you are disconnecting the est wire when you are timing it that was what I was doing wrong. I kept trying to time it by ear and it would never work until I diconnected it est wire and it ran great for a week till my ECM went. how does it idle. does the exhaust sound wierd at all. did you change your fuel filter.

 

It idles fine ( at around 700 rpm). and no i havn't done anything with any feul componets yet.. i need to go invest in a timing light

 

Don't got waisting you money right away. A timing light is good to have around but they can be pricy. Just disconnect you Est wire and turn the distributor alittle bit at a time and see if it get any better. Make sure you put a DRY rag or something over the distributor when you turn it or you'll get shocked and that no fun. Do this while the car is running

 

now school me on the est wire? im stupid when it comes to this

 

I don't have the pic on this PC its on my moms laptop that about 3.5 hrs away from me. Its on the passenger side of the engine bay on the firewall I for get the color. I am sure someone here has a pic or you could even do a search on it.

 

ok so just to update the problem... My ecu is going out.. the shop said they hooked up a laptop to it and when the problem started to happen, it would shut down the laptop.. So i should be getting the car back in a couple days and i'll see how it runs

 

ok so that fell through to.. I give up..