Does anybody remember much about 91 TPI systems? This car ran normal before we pulled the engine, but it was an oil burner so we performed a total rebuild. After that, we put it on the dyno, made a couple of break-in pulls & re-installed the engine. Everything is hooked back up as it came from the factory. He drove it for a week, it left him walking a couple of times. Diagnosed a no-fuel problem (you could hear the pump stop when the condition occurred). We replaced the pump, strainer, & filter. Now it fires right up and promptly dies. I hit it with a little propane just to check on the cold start circuit. It died even quicker. We pulled the #1 plug (brand new) and it looks to be running too rich. Did we overlook something when we replaced the pump? It now appears to be getting too much fuel. Any ideas?
Your fuel return line or pressure regulator is blocked. The reason your car is dying is because your pump is over pressurizing your injectors. Try this to be sure- find the fuel pump relay dismount and disconnect the relay. jump 12v to the pump. As the car starts to die, pull your jumper, if the motor comes back up, you know your pump is overriding your injectors. Troubleshoot to plugged/kinked return line or inop pressure regulator. I don't remember if your regulator is vacuum fed or not. More than likely it will be the return line. I doubt a regulator would just quit during a motor swap. A kinked line is more likely. Your fuel pump will come on for about 3 seconds every time you turn the ignition on, regardless. If it isn't coming on every time you key it, this also points to too much pressure in your fuel injection system.
I put a fuel pressure guage on that shrader valve fitting back by the distributor. It read a steady 20 psi. I think it's supposed to be 40+? One of the times I ran it up to 3000 rpm and it held for about 30 seconds before it died. The fuel pressure was steady at 20 psi the whole time from before I cranked it, till right when it died. Should I still check out the regulator? Thanks in advance!
Yeah, that should have a minimum of 43 lbs. or so. Might as well take the opportunity to get an adjustable pressure regulator now. What's the rating on his injectors? Is that a 305" or 350"? He should check out www.thirdgen.org - pretty good source of info for anything TPI related.
As far as we know the injectors are stock, the engine is a 305. We did find an aftermarket "viper" alarm system installed. It took a couple of hours to get rid of that crap, it was a lot like pulling tree roots out of a sewer pipe. Does anybody know where we can buy a factory service manual?
Ebay or your local GM dealer for the manual. I would suggest an AllData subscription for that car. They are very detailed and quite helpful. http://www.alldatadiy.com/
