Fuel Delivery / Starting problem / Passlock / ECM???

[Ken Maxwell]

I posted this on another forum , but figured I oughta be over here with you guys since I'm not 25 any more or working on my girlfriends car... Hope ya'll don't mind.

Truthfully, I'm a bit perplexed and have run out of ideas. So, ANY help you care to offer is appreciated.

Having a problem with my daughter's 97 GA SE 2.4L.

Car was exhibiting the classic fuel pump problems of not starting after being warm. Gradually got worse to a point that it wouldn't start at all. (luckily, it decided to not start in my garage, in front of my workbench)

Anyway, after researching this board and some other sources, I finally decided to chase down the fuel system because the pump could not be heard running prior to cranking the engine. Bought a new pump, filter and relay and installed them all. - No luck at all. Pump still will not run. I seem to have power everywhere I need it, but the pump will not run.

I've tried resetting the ECM by disconnecting the battery for extended periods of time (both terminals). But, results are the same. No start.

Another odd thing I've noticed is the theft light is on, but isn't flashing. I tried leaving the switch turned to on for 30 minutes, but that hasn't helped either.

I'm running out of ideas..... And, I can't get the damn thing started to even take it to a dealer or somewhere else to have the codes read.

Anyone have thoughts or recommendations as to what might be the cause?

Thanks - KEN///


PS - we tried reading the codes with a scanner for about 30 minutes, but the car wouldn't communicate with the scanner. SO, no codes...??? Also tried leaving the key on for 30-35 minutes, but that made no difference. Still cranks over like hell, but won't catch - still can't hear the fuel pump running either.

[Ken Maxwell]

Oh yeah....forgot to mention...

No check engine light while trying to start.

Replaced Ignition switch back about a year ago - the switch itself, not the lock. I mention this because I noticed the key will only rotate the lock if it's inserted with a specific side of the key blade up. If not, the lock won't rotate. Could the lock tumblers be worn to a point that they are effecting the passlock system???

[Colin]

Try using another key in the ignition switch . Sometimes if the key is worn the passlock will get the wrong signal and think someone is trying to steal the car , thus shutting off the fuel . If the theft light is on there's a problem somewhere maybe ignition switch etc. I'm a bit concerned about what you said about the computer , you should be able to read the codes ? You could just jump the fuel pump relay and see if the pump starts working . And try starting the car and run it that way . Check for power at the fuel pump with a test light and make sure the ground is good also . ;)

[Ken Maxwell]

Will do....any idea which terminals to jump to bypass the relay?

There's only four, so I guess I'll eventually figure it out....duh...

I share your concern about not being able to get the computer to throw fault codes....for that matter to get the analyser to recognise that the car was plugged to it.

Thanks so much for your reply.

KEN///

[Ken Maxwell]

Tried our original extra key. No difference. - No fuel pump noise, still cranking like hell though??/

[Colin]

Originally posted by Ken Maxwell
Will do....any idea which terminals to jump to bypass the relay
KEN/// Pin 85 - ground / Pin 86 - power from switch / Pin 87 - Pump / Pin 30 - 12V . If you jump 87 & 30 the Pump should run . ( Note 87 & 30 can sometimes be reversed depending on the wiring )

[Ken Maxwell]

Thanks so much. I'll try it today and see what happens.

Really appreciate the advice.

KEN///

[Onca Negra]

good thing you posted here.... i did catch the other thread and these guys gave you more info for your particular prob than i did on the other thread .....my hats off to you guys for finding him more complete info than i had at the moment ...

[Ken Maxwell]

<<<Pin 85 - ground / Pin 86 - power from switch / Pin 87 - Pump / Pin 30 - 12V . If you jump 87 & 30 the Pump should run . ( Note 87 & 30 can sometimes be reversed depending on the wiring )>>>

Power from 87 to ground, but no where else. Jumped 87 and 30 pump doesn't run.

I think the damn switch has locked it out or the ECM has locked-up. I may opt for a computer because of it not being able to read the codes. Can't think of anything else that would do it..

Last question...maybe someone knows......Should I be able to move the shifter out of Park with the key on??? Cause I can't. (even with my foot on the brake).

94 degrees in my garage with the fan running. Too hot to be doing this tonight....

[Colin]

Originally posted by Ken Maxwell

Power from 87 to ground, but no where else. Jumped 87 and 30 pump doesn't run. Ok , you should have power at Pin 86 when the key is turned on , this energizes the solenoid . The passlock must be disabling that ( security light ) . You should still be able to run the pump by jumping 87 and 30 ( relay out ) Or running 12v to 86 terminal to operate the solenoid . Check for power at the pump while jumped , if there is power ethier the pump is faulty or the ground bad . If no power check the wiring back to the pump for problems .

[rixGAphx]

Originally posted by Ken Maxwell
......Last question...maybe someone knows......Should I be able to move the shifter out of Park with the key on??? Cause I can't. (even with my foot on the brake).....
This is another symptom of something wrong within the iginition switch, either mechanically wrong or electronically set by the damned Delco dummies.

You have 12v power FROM 87?
Then the pins are reversed as Ken alluded.

Iff you jumpered 87 to 30, then the only reason the pump won't run is that 1) there's a fault in the wiring from the relay to the pump or 2) the pump is bad.

Are you SURE the pump isn't running? These pumps are the quiet vane-type.
My brand-new pump makes a barely-audible whisper of a whirring sign if I put my ear down at the rocker panel.
Nothing audible inside, and certainly not the click-clicks of old-fashioned diaphragm-type pumps.

Good luck.
-Rick

[Ken Maxwell]

OK guys - gave you one item of bad info,,,...there is NO power at the Fuel Pump relay receptacle - pins 87 or 30. Nor is there anything from the ignition switch. Sorry bout that...humblest apologies.

Also have no power to the ignition unit or power from the ignition switch to it's respective pins. (I rang all those wires as well)

I'll be honest, I'm thinkin it's a PCM unit, cause power signals for both the fuel pump (relay) and ignition systems come through the PCM.

Thoughts???

KEN///

PS - thanks for all your inputs. Much appreciated.

[4kQuad]

Wish HeyDice(sp) would come across this....

I'm still going with the passlock shutting down power.... I have no experince with the things...that's just what makes since.

if the passlock is coming on, then the car thinks someone is trying to still it or what ever so it will not send power to the pump.

So going back to the ignation switch and the play in it. maybe passlock thinks there is a screw driver in there not a key.

[99GrandAMSE]

... we have some GREAT troubleshooters!!!!!! Congrats guys ... keep up the good work :)

[Ken Maxwell]

Did a bit more troubleshooting this evening. Started out with the basics, fuses, connectors, etc.. Nothing abnormal found...anywhere.

Performed the following wiring checks with Ignition switch "ON". Results are as follows:

1. No Spark from DIS
2. No power to ignition unit (DIS) from PCM
3. Low voltage from PCM ref Ignition Low (.78vdc)
4. Low voltage from PCM ref Ignition High (2.1vdc)
5. No power from Igntion Switch to Ignitor unit (DIS)
6. Ignitor Unit (DIS) Ground good.
7. No Fuel Pump Power to relay from PCM
8. No Power to Fuel Pump relay from Igniton switch. (coil power)

Tried re-setting the PCM trouble codes as per the Haynes manual recomendations, - no luck.

I accessed the PCM (at least I hoped it's the PCM) but have not done anything with it other than unplugging the two connectors (power off) to do a physical check of the plugs for pushed pins and other obvious defects. - None found. Wiring is in pretty good condition - fact is, the car is in great overall condition.

Anyone know if I replace the PCM, does it need to be programmed first? What about a new ignition switch lock? More importantly, which is the most expensive?

Sincerely appreciate all of you your help and time.

KEN///

[Colin]

Is the security light on ? . If so it's likely the switch like Rick said .

[rixGAphx]

Originally posted by Ken Maxwell
Did a bit more troubleshooting this evening. Started out with the basics, fuses, connectors, etc.. Nothing abnormal found...

Anyone know if I replace the PCM, does it need to be programmed first?
I don't know, sorry.

What about a new ignition switch lock?
I don't know for your '97, but for my '96 a formal Recall was issued a couple years ago for the switch, something about connectors/insulation/fire/yada, yada.

I KNOW the new switch must be 'programmed' using the same 10-minute procedure as the Passlock.

More importantly, which is the most expensive?
You can prolly get a junkyard PCM for few bucks. How trustworthy is questionable.
You certainly wouldn't trust a junkyard ignition switch. And the tumblers wouldn't match your doors/trunk,glovebox.

Therefore, both are gonna be dealer items.
The price will be whatever you are quoted.
Call around, including Chevy/Buick dealers since they have access to the exact same supply chain as the Pontiac delaer; but since price structure depends on local dealer O/H mark-up, you may find better prices by calling.

Good luck.
-Rick

[Ken Maxwell]

OK - I found it.

We were all close, but none of us gets the cigar.

I pulled the shrouds from around the steering column to have a look at the ignition lock thinking it was maybe a loose wire. And, as luck would have it, I came across a loose wire on the ignition switch (opposite side of the column from the lock) while shaking and moving a wire connected to the ignition lock cylinder.

The way I found it wasn't condusive to accurate troubleshooting or safety, for that matter. - I left the ignition switched on.... While moving a wire bundle, I heard the fuel pump switch on. Attempted a start and it fired off within seconds. Shook the bundle again and it immediately died. Tried a start and no good. Shook the bundle again until I heard the pump start and the engine fired.

Anyway, I went to NAPA and bought a new ignition switch,....just on general principles... took the connector apart and re-locked the wire terminations back into the connector and installed the new switch. - For historical purposes - it was the upper Ignition switch 11 pin connector, Lower obd pin. (smallest gauge wire in the connector). Haven't gone back to look at the wiring diagram to see how it interfaces with the rest of the harness. I'll try to do that tomorrow and provide a little more technical update. Right now....it's Miller Time!!!

For the record, thanks to all of you for your help and support.

KEN///

[HeyDace]

LOL 4K, you were close. I read all the reply's to Kens problem and was pretty much thinking the same thing as every one else until I saw this: 3. Low voltage from PCM ref Ignition Low (.78vdc)
4. Low voltage from PCM ref Ignition High (2.1vdc)

I have run into that a couple times and GM has a TSB on a section of wiring under the radiator support closest to the left frame rail where the feed circuits for the pcm get corroded.

But that would not have helped. lol good job guys!

[Colin]

Originally posted by HeyDace
LOL 4K, you were close. I mentioned in my first post there may be a problem with the ignition switch because of the security light . Anyway , glad you got it going Ken ... :)

[Ken Maxwell]

You did in fact mention it....unfortunately, stupid me was thinking ignition switch LOCK - like with a key - other side of the column. My brain was passlocked....

Thanks again to everyone!

KEN///

[Colin]

Originally posted by Ken Maxwell
My brain was passlocked....
:lol:

[rixGAphx]

Originally posted by Ken Maxwell
My brain was passlocked....
Great quote!! Oughta be stickied, or made into a smilie :passlocked: :thumbup:

Glad you're on the road again.

-Rick

PS: Ken-Your missives were very well presented, very clear and concise and with a nice touch of humor.
Do you do any writing?
Just curious.

[Ken Maxwell]

I write in my day job.....I'm a Field Rep for Gulfstream Aerospace. My writing style is a result of doing that job.... for a really LONG time. I guess the humor comes naturally...

Thank you once more for all the help and support.

KEN///