Plz help car not starting

My bro has an 01 Z28, he loves it death but he has a problem starting it. Its getting really bad now but almost everyday no matter if the car is hot or cold or warm and no matter what time a day the engine just won't catch. He has taken it to the dealership twice now and they did everything they could and could not find anything wrong with it. So they said trying getting a new computer for it well he did and today it started not starting again. So he is getting totally pissed of and wants to sell the car now but im trying to convince him otherwise. All the parts in the car work there is a new fuel filter, Fuel pump is good, battery is good, so is the ignition, according to the dealership there is nothing wrong with the car. But we get home and it just wont start it cranks but the engine jsut doesn't catch

Do you guys have any idea of what mite be going wrong plz plz help me figure out what is wrong with it, i love that car i dont want him to sell it

PLZ HELP!!!!!!!

my car did that and it turned out my dizzy cap and rotor were fried try changing those

my car did that and it turned out my dizzy cap and rotor were fried try changing those

01 Z28 do not have "dizzy caps or rotors".

Well anyway, did they check the crank sensor? I believe it is located towards the bottom of the block. I can not believe that the GM diagnostic computer could not pinpoint the problem.

Yeah, my first suggestion, having worked at a dealership, is that you find another GM dealership, and have them look it over as well. that car is a roling computer, with sensors out of its ass, it should be able to tell you almost exactly whats wrong with it.

But more to the point, What it almost sounds like is a wiring harness rubthrough, either to the fuel injectors or the ignition system, usually on the back of the block where its hard as shit to find them. This would explain why the techs might not have seen it act up, harness rubthroughs are a pain in the ass because they are an intermittant problem. you can hook the scanner up, and everything is working fine, but push the harness a millimeter one way, just enough for the rubthough to touch metal, and all of a sudden stuff dies. in this case, seeing as everything else works but it wont fire, i would say its on the fuel or spark circuit, does the exhaust smell really rich???? have you tested for spark yet?? or did the dealership do this?

oh and the reason i suggest another dealership, is that alot of the techs at dealerships are just kids that are moving up from say, NTB and such, and are great at grease and gears, but when it comes to the electronics controls they are completely lost, the only reason i learned how do handle them so fast, is i was a tech assistant to a guy who has been doing vehicle electronic work for the past 22 years. and he taught me almost everything he knew, although he still had far more experience than i did.

lol, oh yeah the point of THAT was to say you should try another dealership, because not every dealership has that guy who does electronics, so the first place you went probly had alot of grease monkeys, and no techs, you need to find where the techs are all hiding.

since your brother wants to sell it just buy it from him. maybe he will even give u a brotherly discount. best thing though is like 89 iroc said take it somewhere else and suggest they check what he said.

nope the exhaust doens run rich we we do get the car started it runs perfect with no flaws i believe the dealer went inside and ou to fhte car and didnt find anything i believe they check the sparks. My bro just took it in today i dont know where but let hope it gets fixed

Hopefully it does work, but I would also have them check the MAF sensor and the crank sensor (with an osciliscope). Sometimes when sensors are going bad, but having gone completely the computer will take the info as good, but there may be a break or several breaks in the wave forms. Those intermittent problems can cause problems like not running or staying running and sometimes will not request the MIL to turn on. (ses light)

an osciliscope???????? you mean a multimeter???? we havent used osciliscopes in ages.

This seems to be the problem I am having... does a dealer haev to fix this. If it is indeed a case of the wireharness rubbing against the fuel injectors can I just move it and secure it away? Also are there any websites that have diagrams of the chevy camaro so that you can easily find everything?

an osciliscope???????? you mean a multimeter???? we havent used osciliscopes in ages.

oscilliscopes are used more for ac signals, but i cant imagine a tech trying to lug an oscilliscope into an engine bay, or under a car. haha, that'd be a sight to see...

dont ever replace the ecm on a hunch that it could be the problem, a "bad computer" is an idiot diagnosis. although it is something to check, i have never seen one go bad without cause.

as for the wiring harness rubthrough, i some how doubt that to be the problem. the car is new enough that the harness should be in no danger of that, and almost every electrical component on a car is fused.

the only thing i can suggest would be a spark plug change. they are built so crappy anymore and they use cheap materials. when they get old they dont like to spark anymore, but once they get hot they fire just fine. i've seen a few cases where i'll pull a plug out and it fires just fine against the block, but under compression the like to crap out. just my :2cents:

Check the coil wire. Had a '97 Z-28 come into our shop the other day with similair troubles. His problem was corrosion.

wire rubthroughs are a very common problem with current GM vehicles, i rarely worked on cars older than a few years, and most were within two or three years. and definatly had harness rubthroughs on vehicles under a year old. so the age of the vehicle dosnt mean anything in that regard. and in fact, i diagnosed a malibu, 2004 with a harness ground out from the factory, they bolted the driver seat down on the harness, pinching the power window wires, so when you put the windows down, and tried to put them back up, the fuse blew. that was a fun one to find. :)

an osciliscope???????? you mean a multimeter???? we havent used osciliscopes in ages.
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oscilliscopes are used more for ac signals, but i cant imagine a tech trying to lug an oscilliscope into an engine bay, or under a car. haha, that'd be a sight to see...



I know exactly what they are and how to use them. I don't know what the hell kind of scope you've seen or used, but I use ones that are smaller than a tech 2, easy to hook up and have found bad sensors because multimeters couldn't pick them up. And they pick up both AC and DC. So why not worry about the problem instead of making dumb ass comments. If what you say doesn't happen to go along with what someone else says just reply and forget the other post. If you know that what someone else said could damage the car in some way then worry about it.

hey man, calm down, wasnt a personal attack, its just that i was a chevy tech assistant (but really more of an assistant shop foreman) and i worked on almost nothing but vettes and electronic complaints, and in the two years i did that i never used an oscilliscope. i was just trying to clarify, alot of people wouldnt know the difference between the two. so dont take it personally.

I know exactly what they are and how to use them. I don't know what the hell kind of scope you've seen or used, but I use ones that are smaller than a tech 2, easy to hook up and have found bad sensors because multimeters couldn't pick them up. And they pick up both AC and DC. So why not worry about the problem instead of making dumb ass comments. If what you say doesn't happen to go along with what someone else says just reply and forget the other post. If you know that what someone else said could damage the car in some way then worry about it. -quote-----------------------------------------------------------------------

hahaha man that was a bit over the top, but 86tatpi is quite right. a digital oscillascope is a fairly small, hand held tool much like a scan tool. and they are absolutely the best for finding intermittant problems with sensors, injectors, and such.