'90 IROC TPI - Engine would idle, but not pull the car. Discovered vacuum leaks around intake manifold. Removed intake and replaced all gaskets from intake manifold thru throttle body, incuding new o-rings in injectors. Now car will not run. Checked timing, fuel pump, and replaced fuel filter. Engine almost starts - so I'm getting spark and fuel. Seems acts like it could be flooded, but I'm out of ideas. How about you?

Without seeing all the connectors etc. it is hard to say exactly whats up. I trust that you reconnected everything that you unhooked, and have assured the firing order of the wires in the cap. If it sounds like the car is trying to start, then we will assume you have spark. You say you checked the timing...what procedure did you use??? Did you disconnect the reference wire when setting it?? Sounds to me the timing is too retarded.
One note- on a TPI equipped car, if there is vacuum leaks, the car will generally just idle faster than normal. Should run fine. Another thing to check, you say the pump is good, how did you check this?? A weak pump will cause poor performance at part to full throttle, but will idle ok. Let us know whats up!

Dave.

Thanks for the input. I too assume all the connectors are right and have checked and rechecked. Was worried I installed distributor off a notch or two, but checked twice TDC with timing mark at '0' and compression at No. 1 spark hole. Rotor fell between 1 and 8 on distributor cap as advertised. You got me rethinking the fuel pump deal. I just disconnected a fuel line and observed spurts of fuel, but really have no idea if quantity or pressure is correct. If as you say vacuum leaks won't cripple the TPI, then maybe I should look closer at fuel pump (already put new filter in) and check it according to tech data. Thanks again.

Use extreme caution when disconnecting the fuel lines on a car with electric fuel pump!!! The TPI setup is designed to run at 38-42 psi. If all you got was spurts, then I would guess maybe fuel pump. It should've sprayed like a banshee out of an open line. There is a fitting on the fuel rail that is to hook a fuel pressure gauge.
Good luck!

Dave

Dave - Thanks for the headsup and input. I checked the fuel flow and got about 24 oz in 16 secs so volume is good. However, pressure reading came up with about 15 psi. I couldn't use the schrader valve on the fuel log because I didn't have the right connector. Just hooked my pressure gage to the fuel delivery line. Looks like I need to change the fuel pump - now the fun begins! Thanks again for the responses. Goose

Dave - Before I jumped into the fuel pump project I purchased a fuel pump pressure gauge and checked the pressure at the schrader valve on the fuel log. I got 40 psi so maybe fuel pump is working after all. So started to check around for some other thing giving me the no start condition. I found a lot of fuel in my crankcase so changed oil and filter. The engine only gives signs of wanting to start when throttle is on the floor like when trying to clear a flooded engine. Although it will fire with throttle on the floor it still will not start. So if the engine is extremely flooded any ideas why? Could my injectors be causing problems? The only thing I did with the injectors when I had the intake manifold off was to put in new o-rings. I don't have any leaks from the injectors or the fuel log. Sorry about this long message and thanks for any help. I am really puzzled. Goose

OK, It hass been a long time since I messed with a TPI car, but can you unplug the injectors? Like, does the injector harness have a plug? I have seen some TPI cars, and many TBI cars, that flooded, and I could only re-fire by unplugging the injectors and spinning it over till it started. It should spit, sputter, runb, and then die. PLug the injectors back in and try to fire it. Or just unplug the fuel pump and do the same. DISCALAIMER: Years agao I was a class "A" tech, ASE certified. I can remember when TPI was new. I was very good at one point, but technology has blown by me. I guess that's a comment on how fast cars change, I'm only 28! So don't take my word as gospel, it has just worked for me in the past.

That is something to try. Maybe the plugs are so gas fouled they will never fire. Might try a new set of plugs, too. Still kinda sounds like timing is late. With the key off, unplug the connector that is for the timing reference, it is over the heater box somewhere. It pops out of the plastic loom, then has a connector, then back into the loom. If I remember it is a brown or tan wire, possibly with a white trace line on it. Then crank it over and see where the timing is at. If and when it fires, then set the base timing, re-plug the connector, then shut it off, disconnect the battery for 30 seconds to remove the code from the computer, then it should be fine.

Thanks guys -
I tried starting with injectors electrically disconnected, didn't get much help. I have been worried about the timing. The Haynes book I have said with engine at TDC on compression stroke the rotor should be between No.1 and No. 8 on the distributor cap. This is where it's at, BUT every other Chevy engine I've ever set was supposed to be on the No. 1. Is the book right? I'll also check timing using your recommended procedure and see what happens. Just put in new plugs. Thanks for your time. Goose