This car is giving me fits....It used to run just fine! Here's the story: I went on vacation last weekend - when I returned I noticed that it rained something terrible (yes my car was parked outside in the rain). I started the car a few days later and everything seemed normal. I was letting it idle (for about 2 min.) and then all the sudden it just died. It will not start. The starter cranks fine but there is not a hint of the engine catching.




I have checked the ECM(there are no codes)
Check for fuse block for bad fuses(all were fine)
I have checked for spark with a timing light(we got spark -it flashes)
I have checked the fuel pressure on the fuel rail( got 43-45 psi - OK)
Siphoned out gas tank and replaced with new fuel (no water found)
I have checked the air filter and exaust for blockages(no problems here)
I have checked the VATS pill circuit for the key (it's OK)
Fuel injectors harness is pulsing fine!
Replaced MAF sensor with known good MAF sensor (still same problem)Disconnected battery and reseated the ECM connectors (seem OK)
Still won't start ... still no codes on ECM!
Probed the fuseable links on main + distribution post(both sides have 12volts)
Checked the fuse block again and found that I have no voltage on FP. or INST(LPS) with the ignition on in any positon(checked with probe light). Is this normal? I know the FP. is for the fuel pump relay -- but I have pressure! Any body got any ideas?

 

It's a riddle surrounded by a mystery, wrapped in an enigma.

 

No 12 volts on the FP fuse until the ECM enables the fuel pump relay. If the ECM sees reference pulses from the distrubutor (such as engine cranking via the starter) it will keep the fuel pump relay enabled. Otherwise it will only enable the fuel pump relay for 2 seconds.

The fuel pump can also receive 12 volts when the oil pressure switch, which closes when the oil pressure is above 4 psi.

No 12 volts on the INST/LPS fuse until the headlight switch is in Head or Park.

Remove the injector plug connectors and measure the resistance of the each injector coil. Should be close to 16 ohms. One injector with a shorted coil winding can cause problems with the other 3 injectors on the same bank.

Also remove the distributor cap and verify there is no moisture inside of it.

 

pull the distributor cap, not only check for moisture..inspect it closely for cracks.

 

No 12 volts on the INST/LPS fuse until the headlight switch is in one of the on positions...Got It ... good tip! So I guess that the voltage on INJ 1&2 act the same way...the ECM turn that on too?

OK --I checked each injector all are close to 16 ohms.

OK --I did this earlier today --I removed the distributor cap and verifed there is no moisture in it.

ECM enables the fuel pump relay. If sees reference pulses from the distrubutor (such as engine cranking via the starter) it will keep the fuel pump relay enabled. Otherwise it will only enable the fuel pump relay for 2 sec.

F.Y.I .I just sprayed some ether in the intake and cranked the car and it turned over and ran until it used all the ether up ......so it seems that the engine is not getting fuel in some way!

How can i get the fuel pump to run with a jumper wire?
How do I test the distributors reference pulses?
How do I test the oil pressure switch?

 

I also tested the harness side of the fuel injectors with a actron III tester and it shows that I am getting injector pulse voltage from the ECM.

Does this rule out the need to check the distributor pulses from the ICM?

 

Does the fuel pump run for a second or 2 when you first turn the key to on (before start). Have someone else turn the key if need be so you can listen back closer to the pump.

Also pull the fuel door & rubber boot, you can unplug the connector for the fuel pump & see if you get voltage for the 2 seconds at key on.

seems weird that you have injector pulse & fuel pressure but no injector "action". As in if the injectors are "really" pulsing with fuel pressure in the rail, you should have at least a momentary fire up.

If you don't have one, now is the time to pick up a factory service manual. It will have a nice diagnostic chart to work your way down & elminate the problem without just throwing parts at it.

 

I have a fuel rail pressure gage (also has a purge valve to release the pressure) hooked up and yes the pressure go up when I turn the key.
I felt the engine should atleast try to fire too.

I know there is a factory installed test lead to run the pump manually....where it is I'm not sure and I'm not sure If it should be grounded or have 12v applied to it?

 

...if he/you has/have a fuel pressure gauge connected and it shows pressure, why would he have to bypass the relay to run pump?...it would seem to me that there is fuel pressure up to and including the fuel rail, indicating that the pump is running........QUESTION; how long can you keep the car running with the "spray"?...the reason i ask is because you could have a thermally intermittant ignition module crapping out very fast when working OR an electronic spark controll module crapping out on you (on your car, may be located on the passenger side of firewall on/very near the heater/ac box)......

 

I wanted to by-pass the pump to make sure the pump was staying powered up instead of dropping out after the initial 2 sec. to see if may be the pump was intermittent.

Yeah I found the ESC- it's on the blower motor box on the passenger side. I CRC'ed and reseated the conector.

The car will run as long as I keep the spray going....don't have much spray left.

I hooked up the pressure gage to the fuel rail while it was running(which is longer than the initial 2 sec. it gives you when you crank the key without the engine running) on the spray and the fuel pump appears to be running in the 43 psi range consistantly.

Still when the engine runs out of ether that's it...it won't run.

 

....if either the esc module or the ign module goes thermally intermittant, it can crap out at any given time....i would get a spray bottle and fill it with gas (yeah, not the brightest thing ta do but, it will work) (be sure you are far enough away in case of backfire and get a bottle that doesn't dissolve from the cas!) and continue spraying into the tb for as long as you can and see what happens.....i guess what i am getting at is once the car craps out, does the fuel pressure drop significantly on the rail shrader?.(probably not since it is an electric pump and not a manually driven one) ..you may have to get a esc module or ign module and replace 1 or both.....i had a similar problem and replaced the ign module and that was the problem.....i also replaced the esc module.......at best, you may be able to get em tested and if it doesn't work, you'll have an emergency spare....at some time you WILL need 'em!

 

Seems like you've already proven your NOT getting fuel. Try this, above your knee in the drivers seat remove the cover to the ALDL, there is a top row of pins, and one on the bottom left that's the one you'll want to apply 12 volts to...it should run the fuel pump, and it should start! Just use a short piece of wire from the positive terminal of the battery to the pin.

 

..rick.....he says that he HAS pressure on the rail and it aparently continues to hold (not run out) after the car dies....is that not an indication that the pump is indeed functioning?

 

sounds like the ECM is not pulsing the injectors. If he has spark, adds ether, and it runs, the injectors are not getting a signal.
There is a fusible link down by the starter solenoid that goes to the ECM.
That needs to be checked. I'm surprised that no one suggested a noid light.
If there's sparkle, and it doesn't run, then there's no food (fuel)

 

.......i think he implied that in post #1 ;

he wrote;
...."I have checked the VATS pill circuit for the key (it's OK)
***Fuel injectors harness is pulsing fine! "

 

Yeah, the INJ are all ok and both banks of the harness are pulsing...I got spark & air too...oh and I got fuel pressure on the fuel rail.

Thanks for your input guys...Tomorrow, I'm going to see which is cheaper a ESC module or ECM for swapology purposes.

I'm going to wait 'till it gets dark to see if maybe I got plug wires that are shorting out or something....shot in the dark! (ha ha) ...'till then I'm going to drink some beers.

 

....ecm (computer) is probably the most expensive...ignition module (under distributor) is maybe $15 - $30...esc module (near heater box) is maybe +/- $75....as far as plug wires go, apply a timing light to the wire and crank...timing light should pulse...

 

yeah - did the timing light thing yesterday for each plug wire...they all made the timing light go blinkedy blink blink. I was just going to check for cracks in insulators. Thanks for the price tips!
This could get expensive...if this is not the problem.

 

Did you verify that gasoline is coming out of the fuel rail schrader valve and not water?

You said your fuel pressure tester has a relief valve so when you release the fuel rail pressure does gas come out of the tube?

 

.....post #1 he stated;
"Siphoned out gas tank and replaced with new fuel (no water found)"