D1SC 383 LT1 Trouble! Need help!!!!

**jmangler** · 10-04-2006, 03:38 PM

Hey guys,

Some thing got messed up and I have no Idea what! Well here's whats done so far:

1995 Z28
4L60E trans
383- 9.79 compression
Forged everything
custom cam
4bolt main
heads ported and polished with matching intake
75lbs injectors
accelleronics injector driver
D1SC -FMIC
headers/catback

Fuel system is in the works, right now I just cruise the car to the local store and such. No hard running. Well until today! My brother in law wanted to take it for a spin and I figured why not, just be easy with it!

Well 10min. goes by and I get a phone call, he says it died on him. I get over their, than he tell me when he turned around to come back he got on it comming out of 1st and into 2nd and it just cut out on him, so he let off and it was barely idleing. If you gave it gas it wanted to shut off.

So I try to start it and just doesnt want to stay running. If I give it gas it would shut off. I figure it had something to do with the injector driver. tested it and all was OK. Fuel pump is kicking, the car just doesnt want to run. No funny engine noises of nothing like that. I get it to start and it idles very low. Finally I diconect the intake for the blower and it runs. Not great but enough to get home. I change the MAF and still the same thing. I changed the stock Fuel pressure regulator and still the same thing??? I still hear the fuel pump kicking on when I turn on the key... I dont know what it can be. I even pulled a couple plugs and they looked ok?????? I'm LOST!!!

**Red on Red WS6** · 10-05-2006, 12:25 AM

That is one reason I never let anyone but me and my wife drive my car without me in it.
Have you hooked up a fuel pressure guage? If not I would do that first.
How old is your Opti and wires? If they are good I would then move on to a compression test.

**jmangler** · 10-05-2006, 01:50 AM

Opti spark has about 3k miles on it. Fuel pressure is ok.....

**EviLt4** · 10-05-2006, 03:42 PM

I know this is going to sound stupid, but what kind of plugs are u runnin?

**Blown25thT/A** · 10-06-2006, 11:04 AM

I would double check all the plumbing from the blower to the TB.

**93lt1vette** · 10-11-2006, 02:19 PM

I had a similar problem with my 93
As long as you are maintaining adequate fuel press under load (wich without a dyno or a in car fuel press gage will be difficult to tell) the problem is not likely in your fuel pump filter or regulator.
If I understand right the car will idle fine but dies under acceleration. Will it very slowly accelerate in other words can you creep the RPM up under load if so the problem is likey in the open loop sensors or programing of your FI. under normal steady driving or slow acceleration (and I mean slow) the FI system of LT1 is in closed loop only the O2 sensor is providing input to the FI computation under accerleration or in many cases idle the system is in open loop using all the sensors in the FI system MAF,MAP,TPS,O2,and others primarily in open loop the dominant factors are MAF,MAP and TPS with if any of these sensors have a fault the system will fight its self or falult all together. By design when a fault is sensed the FI should go to limp home mode but mine didn't the TPS failed and I had to nurse the car back home. Dont rely on the onboard diagnostic system to tell you there is a fault its a big help but not perfect. On the other hand if you loose fuel press under load then the problem is in the fuel system.

there is also a small posibility that multiple of your injectors failed but unlikely

**rto014** · 10-17-2006, 08:06 PM

Hey man,
I ran a 95 with a procharger running lots of boost, usually I will blow the hose going to the throttle body, or if you get underneath the drivers side their is a small elbow the hooks into a huge piece of hardware, I ended up having to come up with a zip tie configuration to keep enough pressure that I wouldn't blow out. I can almost guaranty it is a hose problem. At least every single time that it has happened to me.

**ws6geo** · 11-09-2006, 11:26 PM

SOunds like a big vacuum leak before the MAF or maybe something on the intake...

**elmalo** · 11-11-2006, 09:32 AM

I own a 93 trans am and something similar happened to my lt1. I took it to a mechanic and it turned out being several things including the water pump about $850.00 in parts and labor from a family friend who is a mechanic.

**Black96Lt1** · 11-24-2006, 09:27 PM

I had the same problem with my car, and your problem sounds like mine. It ended up being the fuel pump. I replaced it 3 times before it finally straighten up. I did this after replacing the opti and wires, plugs and MAF.