CELEBRATING 20 YEARS!

Started to mess with the car today, and it just didn't want to start. Only been sittin since 1st of Dec. It would start then stall right away. Took about ten min to start with throttle held half open. Finally. Now its running so rich I had to leave garage.
Any ideas what me problem might be, or how to fix it?

Thanx
Jason

try asking the guys on thirdgen.org

Sounds liek its running real rich and holding the throttle half open to get enough air to make the fuel burn correctly... It could be a fuel pressure regulator causing the injectors to "bleed" fuel constantly... It could also be the Oxygen Sensor... I'm just giving suggestions, I'm not that informative about TPI engines... HTH

I'd also leans towards excess fuel pressure. Maybe a plugged return line? Throw a gauge on it and see what it reads.

I've had a gauge on it and I don't have enough pressure. It doesn't hold a set pressure. Very erratic. Its a new pump. No plugged lines, Would the sending unit have anything to do with it?

Thanx
Jason

What do you mean the sending unit? If you can, connect a mechanical gauge right at the fuel rail, to see what the injectors are seeing. What about tyhe pump intake line, is that clear too?

The sending unit in the tank that holds the pump.
I'm going to buy a new one anyway.($100.0)
I had a gauge plugged into the fuel rail, thats how I know it doesn't hold steady pressure. I'm trying to find a gauge that permanantly mounts to the fuel rail.
pump intake line? do you mean line from tank to motor?

Just curious, what is your battery voltage? Maybe check your grounds and make sure the charging system is good shape to deliver the needed voltage to the fuel pump and injectors, etc.

Battery is brand new. I've gone over all grounds I can think of.

find the fuel line return where there is ruber hose on it and pinch the line, then turn on the ign but do not start the car see if the pressure still drops... this will rule out the pump or the sending unit. then if it still drops pull the fuel rail enough to see the injectors and redo the test to see if the injectors are leaking. if not its the regulator.

If the injectors are leaking would I be able to smell gas or see it around the intake?
The steel part of the return line near the intake has 2 kinks in it. Would this cause probs?

Thanx
Jason

1. you would smell gas from the tail pipes.
2. maby slight chance with the regulator.

For sure smells at the tail pipes. It made my eyes burn, running the car in garage.

Anybody?

Regulator would be my first choice, then leaking injectors which you can not tell unless you have them out to test...

The rich issue that you are having may be secondary to the primary problem... its awful hard to regulate if the pressure is not a close constant.

Dead head the pump and check the readings and if it holds perssure, then dead head the fuel rail and see what you have going on...

what wiring are you using for the pump?

Jeremy
Your losing me here. Not knowing what you mean by dead head the pump and rail?

Not sure on the wiring as I didn't wire the car.(buddy). I do know there is a wire to the positive post of batt. that is powering either pump, or pump relay.

Thanx
Jason

dead head means to make the pump push against the gauge and nothing else, no other releif or loops in the system like the regulator provides...

So I un hook the fuel line feed, and hook it up to the gauge, turn on ignition without starting car, and see if I have steady pressure?

yep, unhook the feed from the pump, cap the line with the gauge and check the pressure and watch for bleed off... Hold the pressure a few minutes just to make sure.

Re-install the feed line and repeat the process by capping the return line so there is no way for the pressure to release except by the injectors or the regulators(which regulator will not show up on this test due to the circut being capped after the regulator...)

Tests should show: test #1 = pump issue, Test #2 = injector/fuel rail issue, nothing on either test = regulator issue(best guess scenario)

Awesome info Thanx Jeremy.
Learn somethin everyday.
With any luck I'll be lookin at a new regulator and it'll be a completely different car.

When I first got my TPI swap complete my car did the same thing. it wound up being that the TPS needed to be reset. Before you pulling your fuel system apart make sure that you have all your sensors and timing set right. Here's how...

#1) Use a jumper and jump the A and B terminals on the ALDL box.
#2) Turn the ingnition on, wait 30 seconds and then unplug the IAC (Idle Air Control). Pull jumper wire out.
#3) Now using a Volt meter set the TPS (Throtlle Position Sensor) to .54 volts, do this be back probing the sensor with you volt meter and or using some type of scan tool that shows you the TPS voltage. You should be set at .54 volts and closed throtlle and should stedily increase up to around 4.00 volt at wide open throtlle.
#4) With a timing light, set your timing, I think it is around 8* BTC, you can set it by ear, just stop adjusting when the idle smoothes out.
#5) Block your wheels and set your parking brake.
#6) Start the car and put it in Drive, use the idle adjustment screw on the Throttle body to adjust idle to a smooth idle, if your engine is stock your should be between 500-750rpm.
#7) Shut car off, you may have to readjust your TPS now (ignition must be on) if you made any adjustment with the Idle adjustment screw.
#8) Again make sure ignition is off, plug in IAC, unhook negative battery cable for 30 seconds then reattach.
#9) Start car drive normally for 15 minutes with 1-2 second gear passes.

If all checks out here, and you do wind up replacing fuel system parts to get her running agian. This is a good quick way to get the sensors back into spec and your TPI working right.

Good Luck
Chris

85SSman Thanks for that info.
I got some simalar info off of thirdgen but it wasn't as detailed, so now I know I did a few things wrong.
Hopefully I can check things out this weekend.

A very common and simple failure is the coolant temperature switch. If it fails it makes the computer think the engine is very cold and then the computer dumps fuel to compensate for a cold start.

temp switch?
Where is it located?

There are two of them. There is an Intake air temp either under the rear of the plenum or in the line to the MAF (depending if it is SD or MAF setup)
The coolant temp "should" be at the front of the intake manifold.
There is also the possibility you have fouled the plugs at this point. A cylinder not firing will indicate lean to the o2 sensor and cause extra fuel to be added. that will make the problem worse.
Make a datalogging cable (or buy one for $30)and get familiar with using it. The data output will help you see what is working and if all sensors are reading correctly.Reset the TPS and IAC per the instructions above and check that ignition (and plugs) are in good shape. Then go after the problem.
What ECM/Setup areyou running?