frankvan

I was posting on Meek's won't start thread, but felt i was hijacking a bit, so onto my own tale of woe.

https://rennlist.com/forums/964-foru...tart-help.html

Quick background on my problem:
Parked car around end of January to fix leaking transmission seals for the PDAS locks. Prio to being parked the car started and ran perfectly.
Due to waiting for parts, bitter cold and lack of a heated garage the job took me about a month to complete. AFAIK, i didn't bump jiggle or disconnect any thing electrical for the procedure (just lower panels and lcok cylinders were moved). And because it was sitting i left it on a trickle charger to keep the battery full.
Upon completion the car wouldn't fire up. The starter motor turns like a champ.

List of what i've tried:
-checked all the fuses (originally just 34 and 35, but pulling hair out i have now checked all of them!)
-tried different DME relay (always carry a spare)
-full charge on battery
-different battery from working car
-jump start
-bypassed DME relay (pins 7-3 can hear fuel pump and can feel vibration in fule filter in engine bay)(pins 7-5 can hear cliks from engine bay - ISV and RF?)
-inline spark tester (lights up when engine is cranked meaning sparkplugs are getting spark)
-removed air filter assembly to reduce any air resistance
-ether based quick start spray into MAF while cranking
-arming and disarming the alarm multiple times (FWIW, when it's armed it won't crank but the alarm horn goes off!)

I believe i'm getting spark and fuel. I get the occassional sputter as if it's trying to fire and the dash warning lights go out momentarily but the tach needle doesn't move.
I'm pretty much at wits end. The only thing i can think of is the cold weather but i've left it outside (in subzero temps) at the airport parking lot for a week and it has started up fine.

dfinnegan

Any chance you've disconnected the electrical connection to the back of the MAF? I've done that and had similar symptoms. Also, check that the MAF electrical wire is tied back on itself per TSB 9005

Have you checked the battery? How old is it? I had some strange problems that ultimately turned out to be the battery, though it was far from clear that it was the culprit. Perhaps try another known good battery?

Best of luck tracking it down.

P.S. I installed new spark plug wires this past week! :-)

frankvan

Thanks dave.
Ya, i tried a different battery whcih i really was hoping was the initial problem.
And i checked the maf too. this car even has the tie band around the connector as per the tsb.
Today is supposed to be warm (+8) so i'm hoping that will do the trick (when i get home from work ten hours from now).

I forgot to add to my list of tries:
switched plugs between ignition modules and also switched pirmary ignition leads.

Cheers.

darth

crankshaft position sensor

frankvan

Will a bad CPS show up on the motronic scantool diagnostic?

Just doesn't make sense that the car started fine back in january and now it just won't.
I had a similar problem with my Alfa that turned out to be a stuck MAF barn door - it got stuck in the full open position and kept stalling, but at least it sputtered more when cranking it. (i've checked the p-car's MAF flap and it moves freely).

NineMeister

Since the ecu is a simple computer system you just need to check it for inputs and outputs, but the most basic requirements it needs to splutter is 12v, fuel and spark, so check for +12v & ground to the ecu and then look for an injector pulse and/or spark whilst the engine is cranking over. If you do not have either the conclusion is that whist the ecu is powered up and ready to run, it does not "know" the engine is turning over therefore it does not fire the injector or ignition outputs. I would then look at the speed sensor on the flywheel & make sure that you have not crossed the 3 plugs between the knock sensor (green), cylinder head temp sensor (white) & speed sensor (black).

rarebear

CPS
electronics have their own way of harassing people !

frankvan

silly question but how do you check for injector pulse?

darth

voltmeter

frankvan

voltage fluctuation at two different injector connectors (figured that was good enough)
tried cranking again - for a long time until the starter started to slow down. got a couple of sputters as usual. Could smell gas. looked under car and the crossover exhaust pipe gasket was wet - sniff test proved it to be gas (flooded engine). SHould it be able to leak out of an exhaust gasket?
Waited an hour (dinner was ready anyways) and then decided to check spark again. This time i was not getting any spark. Had to go out but will try again tomorrow with jumper in place of DME relay.
If that's no good i'll be pulling the harness off the DME under the seat and checking for 12v and grounds. I've got a thread bookmarked that labels what should be what.

argh.

NineMeister

964 ignition system has an ignition switched 12v supply to the coils which is often cut by alarm installers, so check this first; this will be the black wire to each coil. The other two are the triggers (green & green/red) and these go straight to the ignition amplifier attached to the coil. The amplifiers each have smaller individual earth wires (brown) and a shared ignition trigger wire from the ecu. To fire the coils the ecu switches the trigger wire to ground.

It would be an unlikely coincidence that both ignition amps go down at the same time, so my money for the lack of spark would be on a bad ground or immobiliser fault (if one is fitted) interrupting one of the wires.

frankvan

thnks Colin.
The only alarm fitted is the factory 928 part no. for the 89 model (the one that is so conveniently tucked in behind the bonnet hinge!) The wiring appears untampered with so i don't think PO ever had an aftermarket alarm.

Will installing the jumpers to bypass the DME take the alarm out of the equation if it is at fault? Or is it even as simple as unplugging the alarm box? Or are there connections on the alarm that need to be bypassed as well.
(I understand the need for keeping alarm secrets a secret, but these cars are fairly old now, the original alarm isn't that good, and if one values it that much they will hopefully get a real alarm installed by a real alarm installer to protect their investment)

And another silly question: it may seem simple but how do you get those plastic covers off the top of the coils? I've pulled and twisted and seperated but can't them off! There must be a trick.

ACtually, I'm going to back up a bit here.
The only work that was done to the car was replacing PDAS interlock transmission seals. AFAIK i didn't disturb any electricals. BUT here is what i did move and maybe there is something close to it that i might have inadvertantly dislodged/disconnected?
Undertrays for transmission (plastic) and the torque tube (long narrow metal piece)
Drain and fill plugs for tranny
lateral and longitudianl actuating cylinders - left the hydraulics intact
Rear Left wheel.

frankvan

getting closer i think
got spark (inline spark tester)
got fuel (disconnected fuel filter and it ran out plus can smell it in exhaust pipe after cranking engine)
dist belt is intact. both rotors pointing at the same cylinder leads and turn together when cranking.
pulsed the 3 accessible injectors with dc power source (the accessible injectors - 1,4,5) and they all click appropriately. i can only assume the other three work as well (the engine should at least fire somewhat on 3 injectors?)

Cranking it -4 temp i got it sputtering enough that the dash warning lights all go out so it thinks it was running but it wasn't enough to keep going - IOW, the key had to be kept turned to the start position all the time. It seems to get closer every day without actually doing anything. maybe it's just a matter of time? With no real clue as to what the problem is...

I'm kind of loathe to start pulling more things apart and actually create more problems than what i've already got.

frankvan

So finally got above zero today (+5 celsius) and gave her another try. i've got fuel and spark, but no start.

Lots of sputtering like it wants to go but just won't fire.
I obviously have fuel because i can smell it out the tailpipe AND it's leaking fuel out of the cat gasket.
I also have spark from watching a removed spark plug (didn't shock myself - yay!) and also using a spark tester on both primary ignition leads.

Is it possible the plugs have been ruined by soaking in gas? Can you clean plugs exposed to too much fuel?

Richard Curtis

What color was the spark when you observed it? If any color other than blue, you've got a bad coil(s).

If you do have a blue spark (eliminating a bad coil(s)), it couldn't hurt to install new plugs.

Have you eliminated the possibility that the CPS is bad?