Big D Mcgee

Just got through hooking everything up in my new project. Engine will run for about 3-5 seconds then dies. Fuel pump keeps running the whole time. I heading to the parts store to pick up a fuel pressure tester and a regulator in case it is bad. Fuel pump is new so thats why I'm suspecting the regulator.

Anything else that it could be? Need to check for?

Big D Mcgee

OK, got the pressure gauge on it. Maintains 43psi before cranking but the pump is running cponstantly. After it cranks, psi drops to 33-35 then the engine shuts off. I undone the pump and it is bleeding off pressure.

I haven't got the pressure reg on it yet. Just waiting for the part to arrive. I got a buddy picking it up for me. Hope that fixes it.

Is it possible for an injector to be hung open??

psiconversion

iTrader: (5)

Sounds like a vats problem. Is this a retrofit of an LT1 into an older vehicle?

Big D Mcgee

Yes, it is.

Big D Mcgee

Would the vats cause the fuel system not to pressurize?

Big D Mcgee

Just got the pressure reg. on, no luck. I suppose it is the Vats issue. I guess I will hit up pcmforless and have them hook me up.

JAKEJR

No, it's not VATS. A VATS problem won't let it run even for a few seconds.

Let's start off with you identifying the year of the engine and what mods, etc. you've recently made.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!! Graduation Day Parade 20 May 2010!!!

Big D Mcgee

Its an engine and obd1 comp from a 95 ws6. I have got all the stuff crammed into a 23' Tbucket. Engine is 100% stock minus the longtubes, CAI, and all accesories deleted excluding the alternator. Pretty basic. Here's a pic of my project.



Once I get her running right, all that is needed is the interior.

psiconversion

iTrader: (5)

A VATs issue will definitely allow it to run and stall out after a few seconds. In a stock application (no retrofit) where the starter system runs through the BCM, VATs typically will cause a nocrank situation. But in a retrofit, if the PCM doesnt see that 50hz signal its looking for, it will cold pulse the injector when the key is turned on, then not fire the injectors because it doesnt see the signal. Resulting in a start and stall out within a few seconds. Not saying that is the problem here, just sounds like a good bet, especially if he hasnt had it turned off!

Big D Mcgee

I Just placed an order with pcmforless. Hopefully the vats is the issue. I have no idea if the car i got the engine from was vats equipped or not so i am crossing my fingers. I plan on updating my heads and cam later on so the money spent will not be in vain. I think they offer a free retune if needed once you purchase a tune from them.

camaroz28383

iTrader: (9)

if its not the vats causing the prob kinda sounds like what will happen if your Mass air flow is either got a bad conection or its plugged in and there is no air flowing through it

Big D Mcgee

PCMforless just got back with me. Everything sounds promising but I was curious about something they told me. Seems they need to put the comp in the "open loop" program due to me running open longtubes all the time.

Won't the open loop hurt performance?

SS RRR

iTrader: (2)

Do they have a base program they can use for a stock engine? If so, then you should be fine since the engine is stock. You just need to definitely use premium fuel since the knock sensor will not be operable (and that's if you have one on the block). The only way to get around using closed loop is if you use the 02's and all active sensors to close the diagnostic circuit. If you are real concerned about it you can always get it dyno tuned...

Big D Mcgee

I have the spark knock, all sensors, and the 02's installed. They mentioned that even with the o2's in use, it would be too much oxygen coming through and the o2's would have problems compensating.

A dyno tune is in the future but I'm gonna wait till I can get some heads and cam.

SS RRR

iTrader: (2)

In that case get it on a wide band when you get it tuned to see what is actually is going on.

Big D Mcgee

Ok thanks.

ulakovic22

iTrader: (12)

An open loop tune won't hurt performance really, but looking at your setup I think a closed loop tune will be fine. If your O2's are in the collectors, you look like you have enough tubing to keep any fresh air away from the O2's causing them to read a false lean condition.

psiconversion

iTrader: (5)

Just to understand correctly, are they saying you have to run in open loop because you are running long tube headers?

ulakovic22

iTrader: (12)

"open" long tube headers, which he really isn't. If you are running open long tubes, meaning no pipe after the collector, you need to stick with open loop because your O2's will be useless.

Big D Mcgee

Ah....I have a 26" slip pipe that connects to the header. I didn't know the extra pipe would make a difference in the tune. I would really like to make use of the o2's if you know what I mean since I went to all the trouble welding the bungs in for them.

I'll shoot them an email and see what is said.