TKidd88

Alright. Sorry for my first post to be an issue but i need help. New to TPI engines but not to third gen f bodies. Just bought it a week ago, havnt a random problem that shuts me down after a hour or 2 of driving.

A little background on the car. 350tpi, previous owner said it has a bbk high flow fuel pump ( i cant confirm although the fuel pump is very loud sometimes), a bbk adjustable fuel pressure regulator(i can see a blue afpr under the intake), and yellow "corvette" injectors (theyre yellow and the p.o. said theyre from a vette but idk) and a 3inch slp catback.
When i bought it i drove it 3 hours home with no problem.

2 days later while riding for about an hour or 2, the cel came on and the car instantly started dying. The more i pressed the pedal the more it misfired popped and slowed down. So i pulled over wiggled a couple connections and it fired up, still missing but i made it home. I came home and pulled all the codes. I got a map sensor code, o2 sensor lean, and tps. I knew i unplugged the tps while the car was idling so that covered that code, the p.o. told me the map sensor died a month or 2 before i got the car and was new and it looked new so that code must have been old to. The o2 lean i just figured happened sometime before i got the car. I reset the codes and replaced the obviously bad spark plug wires.

Now last night after a few hours of running errands, it threw a code and started dying almost instantly. The map sensor again. So after it sit for a hour it seemed fine but i didnt risk it and left it at my fathers. This morning i grabbed a map sensor, my timing light and headed over. Turns out the distribitor was loose and my timing was way advanced. I replaced the map, set the timing and took it for a test ride. Ran better than ever! That had to be it i thought!

Then the cel lights up after 20mins... code 32 egr. Car still ran great so i said thatll be ok, at least its running good. So i reset the light again just to see if it came back.

It did.. this time the car started to die again. Spitting and popping, wouldnt rev, only half *** idled. If you hit the gas it shut the engine down. I hit a parking lot and towed her home.

I ran the codes while waiting for a towtruck and it was the o2 sensor lean again. After 20mins, it fired up and seemed fine. I even drove it up on the flatbed. Im stumped, i was going to buy a o2 sensor but i didnt know if it was even bad or just telling me my engines running lean??

Please help me figure this out. She runs like a new car for a while, lots of power, no smoke, smooth idle 850rpm just like it should be. It also will randomly rev itself to 1500rpm and calm down...

What should i do first?

Edit: forgot to mention car is a 91 speed density tpi. And the fuel pump is very loud sometimes and sometimes it goes away and is very quiet. Seems loudest when you first start it. I dont know why but i feel one of the three changes to the fuel system might be causing my troubles but again, i cant get it to do it when i want and it runs perfect when its not messing up.

Gtpguy

How old is the gas in the tank? If its old, chances are its bad and water has formed inside. I bought a 91 tpi car that sat for awhile and water condensed. The car was down on power, and the ses light was flashing. Popped the hood and the passenger side manifold was glowing orange. Bad gas. Put in some fresh gas and everything changed.

Don't know if that helps, but good luck.

TKidd88

Full of 90 octane ethanol free... all the old gas has long burned away. Im thinking the ecm is bad.

Gtpguy

It's been awhile since I played with a tpi car, dont remember if the map has a relay that goes bad. But it's right by the firewall on the driver side, there's a few of them. They go bad and are like $10 at autozone.

Go to thirdgen.org it's for thirdgens. It's huge. Goodluck