cheese_kake

Ok I have 92' Z28 5.7 TPI , my car has been acting funny lately. Sometimes when warm but especially when cold , the car will kinda hesitate / stumble going from roll (2-5mph) or stop to about 10% throttle but as soon as I get past the half second hesitation or stumble it runs fine. And its actually stalled twice , but only in reverse going from a stop to backup. That hasnt happened very much but it has only stalled in reverse. But sometimes it doesnt hesitate or stumble hot or cold at all. And today driving back from school it felt like I was giving it gas at about 40mph and nothing would happen I would almost floor it and not much anything would happen. But then after a few seconds it felt like it would kick in and throw me back. After driving it till it warmed up it stopped doing that. But it still once in a while hesitates. Also could this be the trans slipping . its a 700R4. Someone please point me in the right direction. Oh ya I almost forgot , intermittently the SES light will come on it used to only come on once in a while but lately it comes on sooner or lately while Im driving at least 15 minutes.

david roush

iTrader: (1)

= pull your codes, first place i'de start.

cheese_kake

this is gonna sound stupid but (and it is) but I've never pulled my codes, and I dont know how. Im mechanically able. But I just dont know how to pull the codes any help would be appreciated.

SSprayd

if your SES light comes on and off it might be your o2 sensor. do you have a chip in it w/ out a low restiction exhaust and 160 thermo. that threw my friends GTA off. his o2 sensor thought that the car was running rich and then that leaded to wrecking his cat. but easy fix though.

SSprayd

your throttle position sensor might be a problem as well.......good luck fixin it!!

cheese_kake

Ive been thinking of replacing the TPS anyway but Ill check that out. But could this possibly be a fuel pump problem because it seemed like I lost power then it all of a sudden came back 100%. Also I dunno what this has to do with it but Ive been fidiling with my TV cable and was able to make my car shift sooner and make it a smoother ride and lower rpms for better gas mileage. And could someone tell me how to pull my codes.

SSprayd

so does it get real sluggish or just not go at all? sluggish = fuel pump, injectors may be a little dirty and not spraying properly

SSprayd

auto zone pulls your codes for you....dont know how much for though!

david roush

iTrader: (1)

Maybe this will help cheese.....https://www.thirdgen.org/newdesign/faq/thirdgen.shtml
Look at the very bottom of the page under "miscellanous"

cheese_kake

Thanks guys Im gonna go have the codes checked. To answer ssprayed , this was the first time it happened and by the way it hadnt warmed up yet I just started drving. And I was pulling out and it seemed like it just wasnt responding like it was goin like 30% throttle when in fact I was giving it around 70% , I didnt know what the heck was going on. So then I just let off and slowly accelerated to 45 , then I tried to accelerate again it would like revv up alittle but not much, and no real acceleration then like a second later it like went back and threw me in my seat , it was like it was asleep and just woke up. I dunno its really got me thinking , could the trans be slipping ? . and could this be because of a possible incorrect adjustment of my TV cable ??
Are they any was to make sure its the fuel pump , this thing is driving me crazy along with the stalling reverse. and hesitation while stopped or rolling ???

SSprayd

trans or torque converter slipping might be another problem!

cheese_kake

But could that account for the stalling in reverse. Or the hesitation from a stop or roll. Also this doesnt happen all the time. The things I mentioned rarely happen. Do you know the correct adjustment of the TV cable??

SSprayd

it would only be your tranny if it started "free reving" during a shifting point, and sorry no i dont know how to adjust the TV cable.

cheese_kake

Oh well thats good news (kinda). At least I know its not my trans cause it shifted fine it just lost power then gained it back. I dont know if it was related to the SES light or the fact that the engine was still cold whatever is happening is not right. Is there a way to better diagnose whether its the fuel pump or not ?? But its deffinately gotta be a sensor or fuel delivery cause other than that incident today its very fast. So the lack in power is not normal.

SSprayd

another thing to diagnose would be your fuel pressure regulator or you IAC

cheese_kake

How would I do that , I mean how do I check the regulator and IAC??

cheese_kake

My car is driving me insane , now today coming back from school the damn things tach is like being eradic at idle and when it climbs or anything , after driving for a while it did it less and less , when I finally got home I think it stopped. WHAT IS GOING ON. Two days ago my car was perfect!!!! , and today on my way to school , the SES light on as usual and I think I gave it maybe 90% -100% throttle dont remember and the SES light went off and it was perfect all the way to school. And my entire gauge cluster is BRAND NEW , could the tach have gone in three weeks or is it something else , please send any info Im about to push it off a cliff!!!!

SSprayd

my guess would be an injector, i had an 88 GTA, and it would start off sluggish so id put it in 1st, punch it, push it up to about 4000RPMs and it would clear up and be fine! this high revving caused my valve guides to go bad. then one night it just quit clearing up, one my my injectors quit. i had to have a way to work and stuff so i ended up driving it on a bad injector, causing it to run lean and in turn knock a hole in the number 4 piston. might need to get your injectors checked before that happens to you. hope it clears out for you!! that sucks! good luck!

John 89 Formula

First off, definetly get the codes to see whats going on.

As far as the tach needle being erratic, when the coil went bad on my 89 the tach needle was acting funny, might be worth getting your coil checked out.

The TV cable, release the retainer and push the adjuster in all the way, now rotate the throttle lever as far forward as it will go, this will pull the adjuster into the right position.

Rob Wade

Quit guessing. It gets really expensive doing repairs that way. If the ses light came on it should have set a code. Go get the codes pulled, then get a manual that will tell you how to run checks to see exactly what the problem is.

JP86SS

iTrader: (1)

For excellent info on how to adjust the TV cable, go to "700r4.com"
Cool, detailed info on the workings of it.
It does more than you think and the setup is critical to the life of the trans.

Other issues, start with the basics
Jumper A & B with a paper clip and get any codes.
Change fuel filter
Check fuel pressure (if fuel seems to go away under heavy load)
Reset IAC and TPS per procedures in the tech articles (main page)
Do some datalogging if you have access to a laptop (make the cable or buy one for about $35)
The diagnostics are there to help you, use them.
You'll save many hours of guessing and you can see that all of the sensors are reading correctly.

cheese_kake

Thanks for all your help guys. Im gonna try to pull the codes this weekend. And ya after giving it some gas it seemed to clear it up great. And it does this whenever the SES light is on , and when I gave it the around 4,000rpm (like you said) , the light went off so I know for sure that they're related now , because Ive tried that several times now with the same result. But Im pretty sure I need a TPS sensor , and an IAC motor. What does my car have its 1992 so is it MAP or MAT im confused with those sensors, what are their locations ??? , oh ya what kind of coil are you mentioning , ignition coil ???

cheese_kake

Today I tried to pull the codes , and it flashed the SES light in the correct pattern but never pulled up a code??? I dont know whats going on since I still have an SES light ocassionally and it does have a noticeably worse throttle response when the light is on.

John 89 Formula

It will flash code 12 three times, then any stored codes three times each, then 12 again three times, and then start over.
If it flashes code 12 more than 3 times in a row then there are no codes stored.
when the light flashes, the long on time is the "10's" number, the short on time is the "1's" number, ( a long flash then 2 short ones equals code 12).

Check the codes again and post them here.

cheese_kake

Ok this kinda confuses me. So after the code "12" . Does it just display the code as a number or it just flashes the code?? Sorry Im confused Im new at the code thing.

John 89 Formula

you have to read the flashes, the code is a combination of the flashes, 1 long flash = 10, 2 long flashes = 20 and so on. Short flashes are single numbers 1, 2, 3 and so on. Put the 2 together ands thats your code. so 2 long flashes, and 2 short flashes = code 22.

the long flash the light is on for about 1 second.
the short flash is about a 1/2 second.

you may have to watch it a couple times to get used to it.

Hope this helps.

cheese_kake

Ya man that helps alot. Between you and Trickster I think I got this down. From here it will be easy I just have to see what code means what. I have a question , what impact would a faulty MAP sensor have on my car.

John 89 Formula

The map sensor measures engine vacuum, the ecm uses this to adjust fuel and spark, among other stuff, if the map sensor is faulty then the ecm will not be able to make proper adjustments.

cheese_kake

That sounds like what I may have a problem with. Since my intermittent power loss seemed like a fuel or possibly spark problem. Plus the MAP sensor seems beat up and has corroded vaccum lines. Well tommorrow morning I will get all the codes written down and I can figure out what the problem is. I hope its just a MAP sensor.

cheese_kake

I pulled my codes. I got a 32 , 43 and 46. I was already aware of the 46 which is the (VATS). But its saying I got EGR (32) and ESC (43).

Rob Wade

A good quality manual will tell you what you need to test to figure out these code issues. What order did they come out. You should fix them in the order they appeared. Some of the other codes may/could have been triggured by an earlier code. This is why you need to fix them in the order the manual specifies.

cheese_kake

It displayed 32 EGR , then 43 ESC then 46 VATS. The VATS has been an intermittent problem for a while it doesnt matter Im going to bypass it soon anyway. But could the EGR be giving me the problems I described earlier???

Rob Wade

Its possible. Again, I don't want to beat the manual thing to death but all of these questions you are asking, and they are good questions, could be explained for you in a GOOD QUALITY manual. Spend the money on one. I gaurantee it will be one of the best "car" purchases you will make. I am sure you will use it more than just this one time. The money you will spend on it will easily be saved in repairs YOU make or cost savings on parts you didn't need to buy.

cheese_kake

Well I have the Haynes manual. Until now I did'nt consider that I might need a better manual. Which ones would you recommend as a better manual?

GMTech

www.helminc.com

cheese_kake

Damn about $105 dollars. Well it says its supposed to be the original GM service manual. I guess its worth it.

1985WS6transam

iTrader: (4)

I am having the same exact problem and I know what you are talking about, am I correct when I say when it is cold it runs like crap but warm it runs pretty decent? My car is having the exact same problem. Auctually when mine is warm it runs great. Did you check for any vacuum leaks? I know I have one and it is doing this, but I cant find it at all. Mine used to throw an EGR code, I changed the EGR and it solved half of my problem. (The warm part) now I just Have the cold part to solve.
Good Luck
Dennis

cheese_kake

WOA man your absolutely right. Mine runs like complete CRAP when its cold then it warms up and its pretty good. But still has some stumble in throttle response. But thats prob my code 43 ESC or knock sensor. To tell you the truth I havent really been able to check all of the vacuum lines. Not a whole lotta free time. But Ill have to check.

1985WS6transam

iTrader: (4)

I also replaced my ESC and did not see any improvement, not that you wouldnet too but I didnt. IDK I auctually HEAR my vacuum leak, I just cant find it. I think the reason mine runs good warm is because the closed loop operation is compensting for the vacuum leak.
Dennis

Rob Wade

Trust me when I tell you that $105.00 will save you way more than that! It should come with wiring schematics,vacuum line routing etc. also. The computer in your car is set up to give the mechanic working on your car all the info he needs to accurately diagnose the problem. Some problems can cause other problems or mask other problems that will be uncovered and repaired as you follow the checklist of things to check. ie: the mitchell on demand tells you (its also what GM dealers use!) that just because you get a mass air flow code it doesn't (and usually isn't) mean the mass air flow sensor is the problem. Many times its the power relay and burn off relay sticking. Cost, about $13.00 each, not $600.00 for a maf you can't return!

david roush

iTrader: (1)

Or you could try ebay.....i've seen GOOD shop manuals (dealership) ones sell for about 75.00..Or this is a really good book to get info on trouble shooting codes..http://store.summitracing.com/defaul....asp&x=29&y=15...part# SAD-SA53

87TPI350KID

MAF RELAYS, POWER AND BURNOFF~

cheese_kake

What about MAF burnoff and power relays ?? I dont even have MAF. What do you mean ?? , Oh and 1985WS6transam , thanks for all you info. Although I cant actually hear any vacuum leaks. I mean I would hear a sucking in of air which I dont. But Ill check into that.

1985WS6transam

iTrader: (4)

I will tell you, and dont take my word as the bible but just from my experiance, when my EGR valve was LEAKING, i did not hear it, my shop teacher who used to have a TPI car told me to do it. so i did and it helped alot.

cheese_kake

Yea your probobly right about not hearing it. How hard was if for you to replace it ?. Dont I just remove the plennum. Disconnect all wires and solenoid, vacuum lines and then the actual EGR and then just reverse for installation. I know the actual process is more involved but is there anything Iam missing???

1985WS6transam

iTrader: (4)

really, it is not more involved then that, just be sure to use a new set of gaskets so you dont cause anymore leaks. You have to undo the throttle body too, this is when I cleaned mine. made it all not black anymore lol. It is not as bad as most people will tell you.

cheese_kake

Throttle body ?? on the EGR ?? I was under the impression when you buy a new one its all one piece?

1985WS6transam

iTrader: (4)

The EGR valve is underneath the plenum (not connected). In order to take the plenum off, the throttle body is infront of it bolted on so that must come off too. I was told that if the inside of the throttle body was really dirty it could cause a unstable Idle. Sorry If I confused you.

Rob Wade

I'm aware that you don't have a maf sensor. ie stands for "for example". Some of the information the mitchells manual would give you is the maf burn-off relay problem NOT the maf sensor! This kind of info could save you lots of cash! What 85ws6t/a is saying is that while you have the throttle body off the car you should run a spray can of air intake cleaner through it to remove the build-up that can cause the throttle plates to stick open causing an irratic idle problem. Runs some cleaner through the plenum while your at it.

cheese_kake

Thanks for clearing that all up. Actually today I purchased my new EGR. And while I was there I purchased my new knock sensor. That was one of the possibilities to throw my code 43. It was only 34.99 what the heck, I would need it sooner or later. Only thing I need to buy now is my ESC and HOPEFULLY that should clear up my code 43. I hope after I install this new EGR I dont still get code 32, and find out I need the EGR vacuum solenoid.