I am working on an Lo3 and it will not idle unless I bypass the egr solenoid and run full vacuum to the egr valve. If I have the solenoid hooked up, it'll have a surging idle for about 15- 20 seconds then die. If I go full throttle it breaks up really bad and will eventually die. Supposedly it has a new fuel pump, plugs/wires, fuel pump relay. Everytime it hits a bump it stumbles like it's going to die. I want to check fuel pressure just incase but what else should I look at? I adjusted the tps, iac, and timed it to 0*.

 

Sounds like your EGR solenoid is either busted or has a vacuum leak, I'd check and replace that first.

Depending on your car these solenoids are either "normally closed" or "normally open" when no power is being applied to them. However, most of the ones I've seen on TBI cars are normally open. This means with the engine off the valve should be closed. If you have a hand vacumm pump you can check it, connect the pump to the end that normally goes to a vacuum source and see if you can pull vacuum on it.

Paul T.

 

I'll check it, thanks. Even when I cap the nipple from the tb to the solenoid it surges for a few seconds and dies. I'm checking fuell pressure on Friday, supossedly it has a brand new ac pump in it so I'm hoping that it's just the rubber hose in the tank that he didn't replace. What about it stumbling when it hits a bump? What would cause that, a short?


Also, when I am under the hood and go full throttle, the fuel stops coming out of the injectors and it stops reving until I let off to about 1/4 throttle.

 

Check TPS wiring and TPS. TPS voltage (dark blue wire) should vary smoothly from about 0.6 at idle position to 4.2 at WOT. You can check this engine shut off, ignition on - DVM will do the trick.

Check FUEL PRESSURE!

//RF

 

I checked the tps and it is .50 idle/4.06 full throttle.

 

OK

but what about Fuel Pressure???

//RF

 

I posted above that I was checking it. I found the issue though, the rubber hose inside the tank is broken pumping most of the fuel right back into the tank.