well first I want to check my prominator pins... new ecm means sending it off to mrbill and I won't see i again for probably a month.

Actually that is a new ecm, I found out the old one was fried when I pulled it so I could send it off for bill to install the prominator. I then found a bad ground and fixed it before I put the new one in. I was kind of hoping the plugs would be ok then I forgot about them... Again this is when I was young and dumb and.... I won't go there . This is a family site.

CAn someone tell me if the plug that goes from the laptop to the prominator is held on by a clip or shouold it just pop off the prominator?

 

Pulled the fuel pump relay out tonight and it has a little black burn mark and a crack from the burn in the on side... I think if I replace that (knock on wood) all thats left is tuning.

I wonder how much a new fuel pump relay is.

 

Cheap - like $8-10 max

 

well after a new fuel pump relay my fuel pump still won't stop intermitently (sp?). I'm beginning to think something in the ecm is fried... I think next I'll have to make sure my fuel pressure is where it needs to be. Is there anything I could have done removing the in tank pump and putting in a in line pump that could make it act this way?

 

Probably the oil pressure switch. Pull the FP relay and see if it still does it. If so then pull the connector from the oil pressure switch, and see if it still comes on. On many GM systems the oil pressure switch serves as a back up to the FP relay. With oil pressure it will apply power directly to the FP, bypassing the relay.

RBob.

 

RBob beat me to the punch. I was going to suggest the same. On my truck,
if I shut off the engine immediately after starting, the oil pressure is still high, which causes the pump to run until the pressure bleeds down. I scanned my gm manual and attached a jpg for you to understand how it works.
Later, Randy

 

great info guys thank you! I'll test it tomorrow.

 

You may have the "Hot Fuel Module" as well. I know every GM TBI Fullsize Van that I have come across has had one. It is a little box with 3 wires going out of it. It allows the pump to run 20 seconds, prior to the initial startup.

 

My GM manuals state that the fuel module is on all 7.4L, G van with 5.7L,
and all other 5.7L over 8500 GVW engines in order to correct a hot restart
(vapor lock) during high ambient condition.

That would explain why the vans have it. My light duty 3/4 ton does not,
as the GVW is 8200.
Randy

 

Is there a way to bypass the high oil pressure switch? I have a high volume oil pump ( about 70-80 psi oil pressure ) and I'm worried the pump will just run forever until it shortens it's life.

 

Ok, now I'm beginning to wonder if I have vapor lock. My oil pressure will bleed down to zero and the pump will continue to run.

Also when I start it up it runs great but give it a minute or two and its way lean. It won't respond to my VE changes it's just lean. I've richened it up but my o2 is still reading lean. Could that be vapor lock?