MY car is dying on me.PLEASE HELP

[qudlaty]

about a two months after i bought my z28 it just died on me in the middle of the road and after about a minute or two i started it up and it was good for about another two monts.( by died on me i mean that the engine just shut off and when you try to start it again it does not want to start it turns gets spark and fuelbut does not start) two months i said right? after that it started to happen more and more often. When it did happen i would pull over open up the hood wait for 3-5 minutes with time it got to even 10 min. for it to cool down and then i was able to start it up again.
I took it to couple of mechanics and noone could find anything in it.
Last one said it has to be fuel pump so i said go ahead and replace it i want to have it fixed before i'll stop in the middle of the highway and get smashed by a truck. so they did.
Nothing's changed still does it.
SUMMARY
After approx about 1 hour of driving it just shuts of and you have to cool it down and you can start it up again but it will die again after couple of minutes. You have to complitely cool it down to have it driveble.
when i take it to mechanics and they tell me we took it for a ride and it was OK i tell them i know you have to take it for a longer ride in order for it to start doing it.
the car is 99 z28 manual with a headers hurst short shifter magnaflow exhaust no catalic conv reprogramed comp and god knows what else.it was like that when i bought it.
CAN YOU GIVE ME SOME SUGGESTION WHAT CAN IT BE SO THOSE IDIOTS CAN FIX IT. THANK YOU VERY MUCH

[mr._bowtie]

Im guessing that the shops you took it to pluged it in to see what codes it was throwing. Is the car overheating? How does it run when its running? How many miles are on it? Were any mods done just before the problems started?

[qudlaty]

no mods done since i bought it.
It is not overheating and no codes - no ses light eather.
54k miles

[qudlaty]

runs great when it runs

[justinakajuice]

I'm guessing that the engine has a sensor telling it to cut off when it hits a certain temperature. It is possible that it is programmed into the computer. I'd see if you could use someones programmer or buy one. That should give you more power even if it doesn't fix it. Maybe you need a new fuel filter? Those are cheap and if you get a see through one and put it close to the engine, you can use it to check to see if you are really getting gas to it. Can you contact whoever owned it before you and ask what the hell he did to your car? Is there any aftermarket intake pieces? Maybe something got into the engine. To check this you should start by looking to see if the MAF sensor has been descreened. If it has, maybe something got past it and damaged one of the wires, which are sensitive and can be messed up if you even touch them. Bad O2 sensors?

[Louvit]

this may sound easy but did they change the fuel filter may be a piece of dirt plugging it up once in a while..I doubt it but it's possible.

[mr._bowtie]

I thought about the fuel filter, but they generally arent that consistant. If there is something inside blocking the fuel, sometimes it would do it right off and sometimes it might not do it for a few days... Just kind of depends. I would still change it though, they are cheap and easy, and should be changed regularly anyways.

[qudlaty]

THANK a lot I'm faxing yours answers to them and i'll ask them what they think about it?
This is a shop where my car is www.keoheauto.com i though they are good or at least better then others who did not know even where to look.
THANKS AGAIN ROB
i hope it'll work

[cooley346]

Sounds like a heat problem. Wrap the headers and see what happens.

[qudlaty]

they are looking over those suggestions right now but he said that they do not have the software to work on pcm but they know someone who does but if the'll do it the way it is supposed to be done the ses light will stay on all the time and i will not pass the emission test because there is no catalic converters on it.
Is that true that there is something called simulators that should take care of those missing converters?

[mr._bowtie]

LOL OMG Yes you have to have O2 sims in the rear 2 sensor plugs, if you dont then the pcm is constantly trying to correct itself by changing the air fuel ratio. They are a absolute must if you delete your cats, run LT's, basically if you do anything to the cats or the stuff infront of the cats you have to have them. Get a set of those and I bet alot clears up. your car will also run alot better with those in. Youll be surprised that adding those will do for ya.

[justinakajuice]

Yeah, we're all right. The problem is in the computer and has something to do with the O2 simulators, I'm pretty sure. The guy probably didn't know how to use his programmer and whacked up all the settings of the pcm. Put the simulators on and reprogram you pcm and I'm almost positive you'll be cooking the tires instead of your temper.