hard starting/long crank time

[kunsan1987]

Well i went and did it.My conversion is done except for the O2 sensor,park switch,400 kickdown and of course to hide the rats nest.
my truck is a 1983 C20 converted to 4WD.350 ci,th400,np208.
I'm using a 7747 with ACSW (this came out of a 88 K30 5.7l,th400,np208).
I hope some one can help me with a couple of questions.
1. the truck does not start until oil pressure is up to 30 psi(guage reading).The ecm is signaling the fuel pump for apx. 2 seconds(checked at the pump).the electrical system looks good relay,etc.could this be a fuel regulator/pressure problem?


2. will it adversely effect anything if i dont hook the trans kickdown to the ecm right away and stay with the pedal mounted switch?

Thanks,Jim

[EagleMark]

We are having the same issue here:
http://www.gearhead-efi.com/Fuel-Inj...erPro-software

Since you have at least a prime time of 2 seconds, it sounds like a different wiring issue. The relay has to be on at key on for 2 seconds then on when cranked too.

A1 Green wire white stripe turns on relay, then it needs a fuel pump signal to B2 usually Grey or Tan.
http://www.gearhead-efi.com/Fuel-Inj...8&d=1331599730

Do you have the crank wire hooked to starter solenoid that senses when in crank position? C9 Purple or Purple White.
http://www.gearhead-efi.com/Fuel-Inj...0&d=1331599730

[kunsan1987]

I'm getting a signal on the GRN/WHT wire.I'll have to check B2 tomorrow and C9 crank signal is hooked up and working.
thanks

[1project2many]

It's also possible that there's a calibration issue if you're still using the older engine. Does it happen with every start regardless of the engine temp, or is it after sitting for a while? Are the injectors delivering fuel immediately on cranking or is there a delay? How many seconds of cranking does it take before the engine fires up?

[EagleMark]

Do tell on what your thinking the calibration issue is! I've never had an issue like this, but then I always start with my own chips.

ACSW was superceeded twice to AMUS...

[1project2many]

ECM delivers a bunch of fuel up front then reduces it the longer the engine is cranked. If mix is too rich it may take a while for it to lean out enough to fire. Early '80s engine had different heads and cam and wasn't always as friendly to EFI swap. Add adapter to top of 4bbl manifold and things really change. More advance can help but cranking fuel table adjustment really makes it better. Sometimes you can diag too much fuel by cranking for 1-3 seconds, stop crank, open throttle to floor (clear flood mode) and crank again. If it fires right up then suspect too much fuel. But none of this matters if there's an issue with getting fuel to the injectors in the first place.