ThreeOhFive

I bought a 1991 Z28, 5-speed, 95k original miles, in exceptional shape a week and a half ago. Car ran and drove great, felt like it needed plugs and wires and a timing adjustment, but still was quick and fun. I drove it a lot, about 400 miles the first week I had it, had zero problems.

The problems started Memorial Day, I drove it around for awhile, it was hot and humid, but the car was running strong, never went over 220 degrees. Just before I went home, I noticed it was really low on gas, and was starting to surge a little. I stopped at a Citco, and put $10 of 87 in it, and started driving home. Just up the road, the car started sputtering, and then shut off on me. I got it restarted and continued to drive home. It killed on me again going around a corner a mile up the road. It started up again, and then made it a quarter mile up the road, and then, would not start. It would crank, or start, run super sloppy, around 400 rpm, and then die. I left it for a few hours, came back, it started up, and I drove it home. I put two bottles of Heat in it, suspecting I had bad gas. Two days afterwards, I drove it down to another gas station, put $40 of 93 in it, hoping to flush out the bad gas. It now runs and drives okay, but it seems to be a bit sluggish. If you put the throttle more than 3/4 down, it will lose power, start slowing down, and kill immediatley, or it will run sloppy, and then die. The car is extremely hard to start, and tonight, it would not restart. It just would idle about 400 rpm, and then die in a few seconds.

It's just so odd that it's fine until you put the throttle down 3/4 or more. It starts up and runs good on cold starts, but warmed up, forget about it...

What's wrong?

five7kid

iTrader: (14)

To determine whether it is a fuel or ignition problem, it's best to know what the fuel pressure is doing when this happens. A fuel pressure gauge is a good investment.

Did the car sit for an extended time before you bought it?

If pressure is dropping off when this happens, your choices are: clogged fuel filter; clogged fuel pump pickup sock; weak fuel pump; weak fuel pressure regulator. You can change the fuel filter and see if it goes away. Fuel pressure regulator is a little harder to diagnose, but not that expensive to replace. If it's the pump or pickup sock, you will be dropping the tank and doing both the pump and pickup sock, as well as the fuel filter (if you haven't already replaced it).

If it isn't the fuel system, then next is ignition. Did you do any of the plug/wire/cap/rotor replacing? If not, and you don't know if they have been done recently, most likely they have either 95k miles, or too many miles on them. It also isn't unusual on these cars for the coil and ignition module to go bad and produce the symptoms you're describing.

Last on the list would be injectors. Kind of doubt that, though.

ThreeOhFive

Got an update, new plugs and wires yesterday, the #1 plug was completely shot, two of the plugs weren't even in the block all of the way, and the back two plugs were original and had never been changed, somebody just gave up because it was probably "too hard to get to". There were two different styles of plugs in it! It misfires alittle, sometimes it does, sometimes it doesn't. The exhaust smells like it's burning something, my guess is it's the seafoam in it. I put a full tank of 93 in it again, it had a half a tank left of 93 so about $40 more in it now, it was running much better, would take full throttle, but it feels pretty sluggish. Just drove it home, made it with out stalling on me. The "SERVICE ENGINE SOON" light came on, halfway home, I was very excited to see it! The car is still hard to start when it is warm, and when you are driving, coasting to a stop with the car in neutral or with the clutch in, the rpm's dip up and down between 500 and 900 rpm.

I am going to have to rent a code reader, I really don't want to drive it much more until we figure out why it is acting up, and I've already been stranded twice, it's not fun, especially because it's really hot and humid out around here!

9D1BURD

You can check the codes with a paper clip ya know...come on aaron..lol. Text me if you need help.

ThreeOhFive

Thanks, I will! New update, didn't drive it for a few days, my daily driver is having suspension problems, The Camaro needs to be daily driven for a week or two. I just got done driving it, stop and go, for 30 minutes, it didn't act up or stall out on me, but it seems really slow, it doesn't have much get up and go. I'm pretty excited that it's not giving me issues and killing on me. It starts right up after it's warmed up, I tried it many times. Other thing I noticed, when it's warm, it idles around 800 to 900 rpm, sounds kinda plugged up, and it smells like it's hot, even though it only runs around 220 idling and 200 driving. It has a steady miss, rpms dip 100-200 rpm, and smells like it's running pretty rich, which it didn't when I picked it up a few weeks ago.

My guess is it needs cap and rotor, and the timing set.

I think the cat might be plugged up? It makes sence that it would be, I drove it a lot with terrible plugs, and it blew a lot of carbon on the garage door lol. It's not really a quiet car, but it's not loud, either. I have to get it fixed by Friday at noon.

ThreeOhFive

Spoke too soon! Now it won't start! It starts, and bogs out. It runs a really low rpm, and there is loud rattling underneath the car. If you give it any gas, it kills immediatly. Kinda wierd it only starts when's it's been running, but if you leave it for 20-30 minutes, it won't start.

ThreeOhFive

Just did the paperclip trick, it ran code 12 three times like normal, then code 45, rich exhaust...