97REaper

iTrader: (11)

Ok so i just installed a lunati 60122 camshaft and has a tune from ion at madtuner but when it starts it will idle for a couple seconds and it will die. turn it back on and gave it throttle till about 4k and will completely shuts off. any one have any suggestions on what to check. thanks.

97REaper

iTrader: (11)

anybody???

lt1_2buku

iTrader: (4)

Have you checked your fuel pressure from your fuel rail yet? May not be getting the fuel it needs. It could be something as simple as the fuel filter. Mine did that about 2yrs ago. It ws just the filter.

guppymech

iTrader: (7)

Is all this happening on the first start up after the cam install? Have you gone over all the electrical connectors? Ion's pretty sharp with the tune and it's good you had it done with the cam change. Hows it run when it runs.....normal or rough?

97REaper

iTrader: (11)

ya i had no fuel issues with my last cam set up.. fuel filter has little over 1k miles on it. but i'm going to check the pressure. and it has somewhat of a smooth idle but cant really tell since it doesn't stay on long enough. maybe stays on a good 6 seconds then completely dies.

guppymech

iTrader: (7)

Sounds like your fuel pump is not running once the engine starts, works ok to prime not working in run. I think the fuel pump circuit is enabled through the low oil press switch. Do you have fp when the engine is running? For testing the fuel pump there is a 1 pin/wire connector that sticks out of the wire harness in the area of the passenger side hood hinge/ ac evaporator. If you run 12v directly to this connector it bypasses the normal fp circuit and runs the pump direct
http://shbox.com/1/fuel_pump_prime.jpg
Thanks for pic Shoebox.

97REaper

iTrader: (11)

how exactly do i run 12v thru that connection?

guppymech

iTrader: (7)

connect a length of wire to the positive post of the battery or the red junction box by the power steering reservoir and stick the other end into the fp test connector.

FAD2BLK93

Our cars do not have a low oil pressure switch to disable the fuel.

97REaper

iTrader: (11)

ok i did the connection and the car stood ran like a champ.. so what does it mean. i need a new pump or what? could i drive it like that temporary or would it damage something? and thanks for helping me out bro..

97REaper

iTrader: (11)

or a bad relay?

guppymech

iTrader: (7)

You don't need a new fuel pump. Something is up with the power to the pump with the ignition switch in the 'run' position. Try searching the web for f-bodies with fp inop in run position issues. I'm at work now but when I get home (9:00pm pst) I'll look in my '94 factory service manual and post up what I can find, hopefully the info will apply to your '97.

Glad I could help and that the cam change runs good.

97REaper

iTrader: (11)

ive been searching all morning. some people say it could just be the fuel pump relay since the pump turns on when direct power is connected and my fuel filter is new. hope its a easy fix.. anyone else have ideas???

DisasterFormula

iTrader: (1)

Can you hear the pump prime when you turn the key?

97REaper

iTrader: (11)

ya i could hear it when it primes the pump.

guppymech

iTrader: (7)

The pcm controls the fuel pump relay. If the relay turns on to prime the rails then the relay works ok. The problem is the pcm isn't activating the fp relay in the key 'on' position.
Read this for more info on possible causes:
http://shbox.com/1/pass_key.html

guppymech

iTrader: (7)

Description of the fuel pump/pcm operation from my '94 GM service manual, verbatim.

"When the ignition switch is turned to the 'on' position (before engaging starter), the pcm energizes the fuel pump relay for two seconds, causing the fuel pump to pressurize the fuel system. If the pcm does not receive ignition reference pulses (engine cranking or running) within two seconds, it shuts 'off' the fuel pump relay, causing the fuel pump to stop.
As a backup system to the fuel pump relay, the fuel pump also can be energized by the fuel pump and engine oil pressure indicator switch. The switch has two internal circuits. One operates the oil pressure indicator or gage in the instrument cluster, and the other is a normally open switch which closes when oil pressure reaches about 4 psi. If the fuel pump relay fails, the fuel pump and engine oil pressure indicator switch will run the fuel pump."

As you can see there are two paths that can power the fuel pump (at least on my '94) but I cannot find support of this description of the oil press sw part of the system in the wireing diagrams.

97REaper

iTrader: (11)

Ok I'm gonna try that in the morning. do you think it be the icm maybe?

guppymech

iTrader: (7)

It's not the icm. The fact that the engine runs fine when you power the fuel pump with the prime plug indicates you have a issue with the fuel pump power circuit. Have you put a guage on the fuel rail to measure the pressure? If the engine ran fine before you changed the cam then something didn't get put back together right. Go over everything you had apart and make sure it's reassembled correctly. If you don't have one I'd think about getting a factory GM service manual for you car from Helm Publishing. This problem is probably throwing codes, do you have a scanner to read them? Give Ion a call and ask him about it as the pcm is a integral part in the fuel pump circuit and VATS.

It's time to start troubleshooting, don't just throw parts at it.