MParks

Car: 1987 Camaro IROC LB9 TPI

Parts replaced: TPS, O2 sensor, cleaned IAC, fuel filter

Hey guys,

I need help BAD, ive been going nuts trying to figure out whats up with my car. The problem is when started the idle will be fine but then lower to about 500. When i go to accelerate the car stumbles and surges really bad theres a huge lack of power with these surges.

The engine light will come on but then it will go off for a long period of time. When the car hits operating temperature, it will bog out A LOT, when you step on the gas hard there is no power, but when you lightly accelerate it takes awhile to get up to speed.

I cleaned out my IAC but maybe the motor is shot who knows, help!!

LWCS561

i have somewhat of the same problem. i dont get any check engine lights. under acceleration the car will have no power whatsoever, and will backfire

Batass

What condition is the exhaust in? Clogged cat?

Sounds like rich symptoms, stuck injector maybe? Faulty MAF?

LWCS561

the exhaust is fine. cat is relatively new

firehawk1724

hey i have a 89 trans am 5.7 tpi and i have some of the same symptoms..sometimes when i go to accelerate it will bog down no power at all and wont go until i let off the pedal..also its hard to start at times and u smell gas out the exhaust very strong. and my also backfires a lil bit at idle(intermittent) and will also do so when it bogs down..

LWCS561

i think ill change the fuel filter and pump relay tonight and see what that does

Batass

It sounds like you are all are too rich. A bad fuel filter restricts fuel.

Any engine codes? Have a practical way of telling if the ecm is in "open loop mode"?.
Bad O2 sensor, stuck injector, bad MAF (if equipped) are the common things off the top of my head that will make it too rich. Also a bad coolant temp sensor will make it rich. If the ecm thinks the motor is still cold and is throwing extra fuel for "choke mode", it will be rich.

O2 sensor is a great thing to do if it hasnt been done in a while. Excess fuel in the exhaust can run them down quick too. Ignition problems can also make rich fuel symptoms. Corroded cap and rotor, bad wires, bad plugs, bad coil. Look under the hood at nightime and look for spark arcing.

LWCS561

well whats the proper way of replacing the fuel filter on one of these? ive never done one on this type of car before

Batass

Its in the manual.

firehawk1724

well i dont have a check engine light on at all...but this rich condition for me seems to get worse as the car is driven throughout the day...if it sits for hours i can start it up almost at first turn of ignition...as the day progresses it gets harder to start i have to pump the pedal and poof black smoke and smell of gas out the exhaust

MParks

Hey man, sorry i was at the cottage for the weekend and couldnt reply. The exhaust is in good condition, it has a gutted cat so its not clogged. We checked fuel pressure and its normal. Fuel pressure goes up when its bogging out. MAF was replaced about 2 years ago. Could a fuse cause these problems?

maybe one thats slighty out of the holder? Obviously a fuse is the a link between connections so i dont know, because to start the car theres a fuse near the battery in a single holder. What amp should it be? I took it out and switched it with another one and the car ran fine, even took it for a 30 min drive no problems right till i got home, ill take it for another drive tonight and let you know how it goes. The problem might still be there.

Anything else i should check? Ing cap is good, wires are new, plugs are new NGK's

MParks

Unhook the connector above the rear axle, turn over the car until it drains the lines, have a cup ready for the fuel to go into it, swap the filters, put connector back in. good to go, i just did it recently it was easy, this is the way your suppose to do it but i just worked really fast.

Batass

I'm not sure what that fuse is for, but I'm thinking head lights. Pull it and see what turns off.

Richer and richer throughout the day? Thats weird. I haven't spent much time on these cars stock. Does the fuel pressure regulator have a vacuum line on it? I have heard of the regulators going bad and the motor sucks fuel through the vacuum line.

Take the car out and run it hard and check every one of the plugs. Try to keep the time between the problem running and shutoff to a minimum. Immediate shutdown will be the most accurate. See if all the plugs are the same color or just certain ones. It can really narrow down the problem.

MParks

I yanked it and it shut off the car, ive been pushing my car pretty hard just to see if the problem comes back and it hasnt, but i think its because ive been driving it at night and it keeps the engine cool. I think its when my car overheats a little bit for example in the city. so maybe a temp sensor of some sort is faulty? ill post up if the problem comes back.

MParks

Alrighty, so i took it for a cruise today and the problems back, i bought a coolant temp sensor for 20 bucks, im going in for a diagnostic test tomorrow to get some codes.

ninetyone

iTrader: (2)

sounds like you may have one or more bad injectors.no codes for this one. also check your cts.what codes do you have?

ninetyone

iTrader: (2)

why not use a paperclip to see what codes you have. also a bad fuel pressure reg. is probably not the prob. your car will run good still even with a torn diaphram,just a little leaner (it will feel quicker when lean!)

ninetyone

iTrader: (2)

get the codes w/ a paperclip and i will help you

ninetyone

iTrader: (2)

https://www.thirdgen.org/service-eng...ht-error-codes

firehawk1724

So my car seems to run rich and hard to start as the day progresses...if it sits for hours starts right up..when I start it when its been driven I have to pump the pedal for it start...also I smell very strong gas fumes out the exhaust and black smoke...why would that be?

MParks

Hey man, ya i know about the paperclip thing, i tried it and my fan comes on and doesnt show codes, i put in a new CTS and so far so good. The surging or stumbling went away a long time ago.

Another reason why i think it might have been the CTS is, it would only bog out during the day when its really hot. Lately ive been driving it at night, good 30 min drives and it doesnt bog out at all, and the bogging was probably when it got hot, couldnt read the temp and made my car run rich as said before because when i stepped on the gas peddle it would just chug and i would smell gas. SO i replaced it, and will take it for a drive tomorrow and see how it goes. Im not saying it fixed it, but i damn well hope so!!!!!!

MParks

Im trying to get these codes from my car, Im doing it right but my damn fan keeps coming on and doesnt show codes!?

ninetyone

iTrader: (2)

fan is supposed to come on. Your ses light may not be working also.

ninetyone

iTrader: (2)

alright check out this link. Talks about testing the ses light. https://www.thirdgen.org/forums/tech...t-working.html

MParks

I got the code its my MAF, i checked all the wires and they look good.

ninetyone

iTrader: (2)

Why dont you just unplug the maf and drive it? It should run a hell of a lot better! LOL

MParks

Im thinking its a relay because the problem comes and goes, im going to a friends house which is a mechanic for GM and also owns a 91 z28 and he said i could try his spare relay. I looked at them and they were pretty rough, If worse comes to worse ill just buy a new MAF.

ninetyone

iTrader: (2)

but have you unplugged it and driven it yet? If it runs better then it is a bad MAF sensor!

87TwinTurboIroc

hey man i hae had the same problem since i bought my 87 Iroc Z28. someone metioned to me that it ight be an ignition problem. I changed my coil with a msd(street fire) coil and its like magic it runs like a champ.

Turin

How did you get it fixed I also have a tpi