Hey fellas, I tried to get an answer to this question last summer, and got no help so Im trying again. My 86z with the lb9 wont start without me pumping the pedal. The car will start without it, but it takes 8-10 secs on cranking, then sort of sputters to a start. If i give it gas when cranking she fires right up, but i have to pump one to two more times otherwise she idles soo low that shell die again. Once shes started though, no dying or idling issues. I just have to pump her to get her to fire. I put in a new fuel pump, hypertech eprom, and ecu. Those are the only mods i can thnk of that ive installed that may affect fuel delivery. Anyone ever had/heard of this issue? And does anyone have any fixes?

 

Check you fuel pressure & bleed down rate.

 

Whats the bleed down rate? And how can i check the fuel pressure w/o a fuel pressure gauge?

 

You need a gauge, bleed down rate is when you shut the key off. It should maintain fuel pressure for a long while. If it drops to zero then there's something wrong, that might be why it cranks so long before starting. The pump has to refill the whole system & work the air out.

 

If you have to " give it gas" on a EFI engine it is way too rich , because putting your foot on the pedal shuts off the fuel supply and allows more air in
There is no accelerator pump on a injection engine like on a carby

 

I read in the service manual or owners manual, If you hold the pedal 1/3 of the way down or less while cranking, it gives it a lil extra fuel.
Now if you hold it to the floor, it goes into clear flood mode.
IIRC

I'd check out the cold start inj circuit if you haven't.

 

Thanks for the reply guys. I had her towed this morning, she would mot start whatsoever and eventually stopped cranking. 8 hours on a charger and it still wont even crank on a month old battery.