Hi, I have a 91 Camaro Z28 convertible with a TPI. I just replaced the fuel pump and if you are familiar with this process you know how difficult it is. I have put the new pump filter & wire harness on and put the tank back up and connected the wiring. I have put about 3 gal of gas in it and started it up. The car will idle put when I push the accelerator it dies. I checked the fuel line at the TPI and I am getting fuel to that point at least. Not sure what it could be. Any suggestions or ideas will be appreciated. Not real sure what I could have done wrong. Thanks

i had a problem with my 91 kinda like that mine turned out to be the tps sensor was bad. it would idle rough and sometime wouldnt idle at all. so you could check that and also check the fuel pressure to make sure its got enough pressure. 34-47psi according to haynes manual is correct pressure.

Thanks Mick. I had to spend $50 to get a fuel pressure tester, but I got it none the less. I started the car and it said it had 40psi. With that being said I went ahead and put the rear all back together. I figure it must not be in the pump.

I have order the TPS and when it gets here and I get it installed I will let you know if that is it.

Thanks

When was the last time the fuel
filter was changed

I changed the fuel filter about a month or two ago and I havent driven the car much since then. Maybe about 100 miles or so.

There is one thing I forgot to mention. Not sure if it is important or not. When I tested the fuel pressure it was at about 42 in the idle position, but when i pushed the accelerator it dropped off quite a bit like 10 to 15lbs. Is this normal? If not what might cause it to do this? The fuel pressure regulator, or could the TPS cause it?

Just thought I would mention it.

That is generally the sign of a bad pump. Not sure if that could be bad regulator though, I guess it's possible.

The first thing you need to do is get ahold of a scanner. That is always the first step whenever there is a problem.


If I remember right with the pump running and the vacuum line disconnected from the regulator your fuel pressure should be 45 psi. The way tpi cars work is the fuel pressure regulator does the low to mid load enrichment by increasing fuel pressure. The ecm does not pulse the injectors more until about 1/2 to WOT. When manifold vacuum drops fuel pressure is increased. Also when the ecm sees the TPS opening it increases ignition timing.

If your fuel pressure is going DOWN when you throttle it there is obviously a fuel supply issue somewhere. Your engine is leaning out to the point that it stalls and dies when this happens.

If you just replaced the fuel pump the next place to look is the fuel filter. Then the fuel pressure regulator. If you replace all these things and you have access to an air gun you can spray some carb cleaner in the fuel lines and blow them out.

Keep us posted.

Pull the vacuum line off the pressure regulator, if gas comes out of it you need to replace the regulator.