`69 Elky W/`90-`92 TPI Needs Ether For Cold Start

elchevello

My first post here.....Why won`t my TPI start unless I shoot some ether into the motor during cold starts ? After the motor runs for a minute or so, it`ll start up no problem all day long. I just can`t let it sit too long. The fuel pump looks like an Accel with 125psi max stamped on it. Could this be a computer problem ? Thanks !

theelcaminofactory · Posted: Fri May 09, 2008 6:14 pm Post subject:

Does your TPI have a cold start injector or has it been deleted? By no means am I a TPI guru, but it may be your problem.

toms84ss · Posted: Fri May 09, 2008 6:19 pm Post subject:

There may be some guys here who can help. But, you may have more luck at thirdgen.org with the Camaro and Firebird guys. They have that TPI stuff pretty well figured out.

wingnut · Posted: Sat May 10, 2008 4:25 pm Post subject:

If you have a 90-92 tpi system, it shouldn't have a cold start injector. It almost sounds like the system is bleeding down through either the pump or the regulator. Have you tried cycling the key a few times to activate the pump? This sort of work like pumping the gas pedal on a carbed car. Mine bleeds down after a few days and is a bear to start if I don't cycle the key a few times before I try to start it. You should check the pressure after you turn the car on and then after you shut it off. The pressure should hold and not drop off.

elchevello · Posted: Sat May 10, 2008 4:52 pm Post subject:

I will soon be replacing my fuel pump with another in-line fuel pump. After doing a little research on other popular TPI sites, it looks like the 125psi fuel pump with stock fuel pressure regulator might be the problem. I`m going to install a new pump rated at 75psi max and also install an aftermarket fuel pressure regulator to ensure proper pressure. I do not have a fp gauge as they seem to be very expensive to me. I just want to sell this rust free Cali El Camino after I get it operating correctly.Thanks so far for the input !

EDIT: I can cycle the fuel pump over twenty times or more without cranking and then try to start the engine with no success. When cold, it needs ether.

hel98 · Posted: Sat May 10, 2008 10:10 pm Post subject:

Are you waiting 10-15 seconds between cycles? The ECM won't activate the pump after the first time without the interval.

Possible the coolant temp sensor is not reading correctly, but not out of whack enough to set a code. Check the voltage at the sensor and at the ECM to see if theres any difference.

Try another sensor if you have one.

Check the resistance of the ct sensor. Should be about 3-4k ohm at 75F.
The resistance increases as temperature decreases.

90-92 should be speed density. The software controls cold enrichment. Are you running the stock calpak?

Has the engine had this problem all along or did it just start?
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