[Siggy_Freud]

Hey all. I am in the process of a TPI sway onto a 72 350 engine. THe TPI is out of an 85 T/A. I believe the wiring is all correct and I know the timing is dead on. The problem I am having is that the engine will start and fire up but quickly starts popping lean and dies. I have a suspicion that either the inline fuel pump im using isn't giving the engine enough flow, or the inline filter doesn't allow enough flow to go through. I have great fuel pressure (around 43 which is a little on the low side i suppose but that will be fixed with an adjustable regulator). I suppose my question is in regards to the fuel pump. The fuel pump was made for an 85 ford 5.0 with Fuel Injection. Its rated at 70-90PSI however I dont know what sort of GPH those engines requred. WIll it be enough for the TPI. Any ideas on this problem. I am not getting any engine codes thrown at me.

Thanks for the input.

Dylan.

[79transam]

We had a similar problem with my friend's 91 TPI formula. Would idle for a bit than die. No codes. Good fuel pressure. Had the injectors flow tested and it turned out one of them was completely clogged. Just a thought..

[greasemonkey1979]

Doesnt the 85s have a cold start injector? is that working? egr stuck open?

[Wrencher]

I'm not sure, but check the fuel pressure specs, very critical, also maybe a failing module, vac leak? Did you watch the fuel press as it dies?

[arch]

My 86 TPI used to do the same thing

Couple things I'd check:

IAC (Idle air control valve), In the front under the throttle body.
MAF (Mass Air Flow) sensor
TPS (Thottle position Sensor)
Unplug the wiring harness from each injector individualy and get a ohm-meter (or multi-meter) and put a lead on each pin and it should read 13.5 +/- 0.5 ohms, any other number and the injector is bad.
You can also check the resitance on the TPS to tell if its good or not, but I cant remember the exact numbers off the top of my head.

I dont remember a cold start injector, 75% sure early TPIs do not have them. Although not positive. However they do have cold start valves in the middle of the intake between the two runners (drivers side?). Plugs into the harness same way the injector does.

Although If any of those are bad you should get a code, however my IAC was bad, and No codes came back for me.

My problem was the IAC and ignition wasnt sparking 100% of the time.

[Rhansen]

The TPS is supposed to read .54 volts at idle. I had the EGR stick open before and the only difference was that I lost .4 sec/4 mph in the 1/4 mile, but drove ok otherwise.

[Siggy_Freud]

Hey thanks for the replies all. This system does have a coldstart injector. The EGR and emmisions have been removed and it supposedly has a custom PROM that accounts for this setup. The ignition module was replaced as well as the coil. The only vaccum I have running goes right into the plenum and then a little line from the plenum to the fuel pressure regulator. And the pcv valce to the plenum. I am thinking its either the fuel pump or an injector causing this. Or muliple injectors.

Any more ideas are greatly appreciated.

Dylan.

[engineguy]

Dylan,
Make sure that the catalytic converter, muffler or pipes are not restricted. I once had a Chevrolet truck that had stock exhaust system, which includes double-wall exhaust pipes. The inner part of the head pipe had corroded and come loose which closed off the exhaust system. Engine would start, run about ten revolutions and quit. Changed a whole bunch of stuff before I finally got it figured out.
Bill