xklipze

I have a 1991 Z28 350 Tpi its pretty much factory, with nothing modified

Car was sitting for a year or so, however this thing starts right up, and drives solid for 2 months. Worked great for months, then out of no where it started being wierd... i have been beating on it a little bit but not too much, but nothing my other camaro's couldnt handle

Currently i can drive around all day under 2 RPM, and everything is great.. it even idles fine. Drives great all day, with 0 problems

However if i try to "Punch the gas pedal", it will take the fuel and u can hear the engine begin to roar

but it gets wierd.. it might start to bak fire, pudder, hesitate bog out etc... maybe frequent little pops.... however this wont happen unless i floor the car... with the pedal to the floor. it will continue to sound like "****" unless i lay off the gas pedal.

Since this problem has occur'd The car hasnt been able to go faster than 70mph without the problem occuring
(Right now im just cruising down the highway without letting it go more than about 2RPM).

BUt when i want to floor the gas pedel, and really speed up... it doesnt go anywhere and 2x rpm is the highest i can actually bring it up to... so city driving is no problem.. but kicking it up a notch and speeding off... just doesnt happen... it doesnt have any punch and instead of punch it has.... a heap full of noise's and boggging , putting etc...

The needle's on the gauges of the Speedometer and sometimes the tach, will start jumping around all crazy like it is haunted.



But if i turn the car off, let it sit for say a hour or so... no more
""service engine soon"" light... its just a normal car.. until i wanna really give it some gas, which i cant....


anything before 2x Rpm The tranny shifts very decent, and doesnt seem like the trany is messed up, i think its an electronic problem, or some sort of sensor problem...

Do you have any suggestions or thoughts.. any input is better than nothing..

also.. i havnt made any modifications that would make this problem occur.


but i do have a free membership to ThirdGen.org, and you guys are the ****, so im hoping someone could figure this one out..... thanx for taking your time to read.

jstrdn90rs

You can check for codes without a scanner ..check in the other threads.One of the moderators have the procedure posted.The inflation light is for the air bag in the drivers steering wheel.If the light is on theres a problem in that area..I am guessing, but your problems sound like an EGR not functioning the way it should...but check the codes first.

1991L98G92

Sounds more like a lean condition with the backfiring. EGR open at cruise shouldn't cause the car not being able to go over 70MPH. Sounds more like a fuel filter/pump problem. The gauges jumping may be a ground problem which could also cause a driveablility symptom. My first thing to do would be change the fuel filter, normal maintenance item that you can't really check if it's clogged by looking at it..

xklipze

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sogabe

did u try resetting ur computer?
its as simple as disconnect the battery, leave it for 20min or so,
then reconnect and start the car and idle for maybe 5min(so the computer learns new variables to the system)

just my guess but i thought the computer is reading stuff wrong or something,
since anything can cause poor drivability, but it shouldnt
give out INFL REST light on. so computer might be at fault or something.

i hope its ur fuel filter though, thats an easy one to do
and yes it can cause rough driving.
dont overlook cheap stuff, if u know some minor stuff hasnt been changed
for a while, start from cheap ones, rotor and caps, sparkplug&wires etc.

hopefully u dont have a knock man.. good luck

xklipze

If my car was in park I would be able to RedLine my engine if i wanted to, , i could goto 3xrpm 4x rpm all the way to the redline.... and it would sound realy nice too.... so i can have this problem while im engaged in Overdrive.... not being able to accelerate... after 2x rpm.... without hearing a horrendous series of random noise's.


it would sound good under the bridge's on the highway nice and clean... so Im really doubting it might be a mechanical problem with the engine itself, thats all i can actually rule out, knowing what i know.... but then i start thinking could there be something wrong with the transmission.. im really hoping that i am incorect.


my car , when it is at idle, at lets say a red light... is running 100% mint... so thats why it gets wierd...

jstrdn90rs

If your engine runs good at an idle then a vacuum line being a problem is ruled out.Have you checked the condition of the trans fluid..if its not red and smells like burnt toast then I would say you have some trans problems.If that checks out then move on to the next area..

Like plugs/ignition wires/timing?

xklipze

Today i reset the computer, and i changed the fuel filter, i noticed a big difference with the sensitivity of my gas pedal from the fuel filter... however the problem has not gone away

Does anyone think this could be because of the TV Cable ?

And my next move is a full tune up, but for some reason i think a tune up is not going to fix the problem because of the fact that the car in neautral or park, revs up really nice...

i hope its not the tranny..

one thing i did notice, is on the test drive today, the service engine soon light came on, as a problem after about 30 minutes driving, so i hope it recorded something

any more advice is very welcome

iceman02

iTrader: (1)

You don't need a scantool to display the error codes.... you can do it manually. Read about it here (link)

xklipze

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iceman02

iTrader: (1)

ahhh, but you must count the flashing..... those are the codes. If it flashes 4 times quickly in a row, then a pause, then flashes 2 more = code 42. Then it will go on to the next code.... try it.

Duck

Similar driveability symptoms in my '87 5.7 TPI went away when the high-mileage original distributor was replaced with a MSD dizzy, along with new spark plugs and wires. Good idea to also clean the connections of all the electrical components and sensors, to ensure data isn't being lost before it gets to the ECU. Check the fuel pressure too, to ensure it isn't dropping-off at higher RPMs.

xklipze

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xklipze

ok i got the Computer to WORK it told me i have 1 error
I used a paper clip, and figured out my error code is #32

My chiltons book says #32 is EGR Failure



So does this make sense with the problem i am having, and also, i take it... the problem would be THE EGR VALVE itself ...(am i correct?)


Which i can figure out how to fix, in the chiltons and from that autozone website.... thanx for that link...



OK so Does it make sense my problem i am having is INDEED my EGR Valve..??

Or do you think the problem is still something else.. Something that is causing the EGR valve to FAIL... and trigger my Service Engine Soon light ???

anyone who has ripped apart an EGR valve, wanna throw me some tips of any kind.. im going to be tackling this later today i'd love some advice.. Priv Msg me...

stew'86MCSS396

Welp...with the code 32, this makes a little more sense. IIRC EGR don't work with park/neutral switch in park or neutral.

xklipze

Is there any way to bypass the EGR system, completly... i know its possible, cause i think i seen you guys talking about it..

I just cant figure out whats going on... so i figure if there is a possible way to just eliminate all the EGR components and pieces, i dont think it would be illigal, and would technically fix my problem.. and let my car drive

So is this possible on a 1991 z28 5.7 TPI ?

feel free to be as detailed as possible...

And to keep those of you updated..

the original problem was... the c ar started running like ****.... then it would not go past 70 or more than 2and a half rpm about.. tach and speedo kept jumping around... but more importantly the car just couldnt be floored at full throttle... it would make crazy noise's..

what i did was replace the ignition switch(which didnt fix the car starting problem with the key, (only the remkote starter button works to turn the starter))
I then cleaned the EGR Valve alot... replaced all the rubber hose's that were 5/32 diamiter... even the little ones.

i replaced the spark plugs, spark plug wires, distributor cap, rotor, and ignition coil...

Im thinking of now replacing the ignition module, maybe the fuel pump.. do you guys think i should replace the carbon cannsiter? or replace the egr solenoid?

You guys think it could be any other problem..}

The car doesnt even start no more, it just drains the battery by cranking the engine...


at one point, the car would stall after deaccelerating, and coming to a stop light of some sort, the engine would die.. then it would take 15 minutes to start again, anmd i kept my foot on the gas pedal the whole time

The starter just was replaced.

When i try to start the car, it turns over, and sometimes takes for a split second, but doesnt quite start up....

Do you guys think its the ECM? the car used to start and idle great.. but after like 20 changes it kinda stopped doing what i wanted it to do... and now im soo stumped

Im gonan change the egr solenoid when i get the money friday... but feel free to add some input..

so many problems right now... going insane..

1991L98G92

First of all, if you have a code 32, the EGR probably isn't working, in which case, would not be causing the problem. Second, disabling the EGR, or any emission component is against the law. Doesn't matter what state your in, it's a FEDERAL law. Notice on your emission label it conforms to FEDERAL and/or CALIFORNIA emissions. That said, all you have to do is disconnect the vacuum hose to the valve, drive the car, and if your car is still acting up, you have ruled out the EGR as the cause, and hook it back up because it's not the problem. Another thing to do, is hook up a fuel pressure gauge and mount it under the wiper blade. Drive the car and notice any fluctuation at the determined speed. If you don't have one, or it's frying your brain, don't throw a lot of money at it and take it to a reputable repair shop. Pay the $90 or so and let a professional take a stab at it. You will save time and money in the long run. Then, if you feel what they find you are able to fix it yourself, have at it. But remember, sometimes there are multiple problems that have to be done one at a time until your back to normal. You could have an electrical problem on top of it all. Maybe an injector problem. Without a proper diagnosis, and the means to do one, you are just SOL. Good luck.

D's89IROCZ

you said the speedo goes all wonky ? I say the VSS is shot and it's messing up the ECM because of it.

xklipze

the original problem was a mess, and im not sure if it is fixed.however i must add, yesterday i installed my known to be good battery, and i ran new terminals on the battery (top-post) and ran new wires to everything that needed positive, and i got the car to start and run on its own with starting fluid.

but the car doesnt stay running, but this prooves my tune up worked good.. any thoughts now?

xklipze

the car is fixed, i dont know what i did. but it drives great all day.

Thanks to everyone and thanks to VADER

what fixed the car, was a combination of things, a complete tune up and new positive and ground wires, i ran new ones.


Thanks ThirdGen.org ALOT!!!

car is running like a charm, and no more problems with CRAZY tach and crazy SPEEDO..
or intermitten radio power thanx everyone... vader those emails were like my bible.

xklipze

today im gonna adjust my tv cable after i find the article on that the car has been running solid,and im convinced its with the new replacment of them power cables to the computer / acc new power wire from the battery to the alternator and new power wire to the starter (a story within itself) but the car starts drives and runs beautifully, i still have the problem of starting the car with the key.... wish i knew how to fix it, i even replaced the igniton switch, maybe i need to run a new wire from somewhere to the starter who has thoughts about that? well thanx alot guys car sat for a month and now im driving it again, and no more problems, what a damn relief.