How to test 3.2 ignition triggers, missing on half the plugs

[Mark Henry]

Did a full service on a none OP (to me) 1987 911, new head studs (2 broken), rebuilt heads, plugs, clutch, fly, triggers, fuel lines, air box, etc.
Except for the Standard wires and fuel line, all parts were from our host.
Replaced triggers as the wire covering disintegrated.

Starts and I can get it to run up (sluggish) to 2500rpm, mechanically all seems good, but seems like it's only firing on 3 cylinders, as pipes 2,4,6 (IIRC) are cold.

Replaced with new cap, rotor and Standard brand plug wires, runs like poo.
Then tried the old cap rotor and beru OE wires back on, slightly better.
Tried new beru wire set, about the same as the old OE old set.
Tried new cap, rotor and beru wire set, same.

Coil and CDI are stock.

Unrelated but did have issue with the rebuilt starter noise (squealing), replaced with a WOSP (from host) and the bad noise is gone.

Any suggestions of what to try would be appreciated. Thanks

[proporsche]

do you have the distributor rotor in the right place not pointing to no.4 on Z1??? And the spark plugs wires on the distributor cap correctly?
I suppose the camshaft timing is correct ,right?

Ivan

[NotStock]

Maybe I'm dead wrong, but the 3.2 uses the distributor to decide which cylinder sparks (but not the timing), so if some cylinders are consistently firing, the ref sensor/DME are probably doing their job. I'd use whatever method you prefer to check that those cylinders are getting spark, then I'd start checking for stuck injectors.

[nospiners]

If firing order and distributor placement is good , fuel system up to par ,then its valve adjustment and cam timing .

[Mark Henry]

Originally Posted by NotStock

Maybe I'm dead wrong, but the 3.2 uses the distributor to decide which cylinder sparks (but not the timing), so if some cylinders are consistently firing, the ref sensor/DME are probably doing their job. I'd use whatever method you prefer to check that those cylinders are getting spark, then I'd start checking for stuck injectors.

I ran into a friend, long time Porsche wrench, he also suggested injectors. Didn't think of this as owner said they were just rebuilt locally, but he said many "rebuilders" are hacks. I'm going to check this first.

I've rebuilt many stock and mod engines and never had issues with cam timing, and used a kirk valve adjustment tool. I've done top ends and studs on 3.2's before, as I rebuild engines...just never installed a 3.2 into a car. Most of the time I get the longblock, do my thing and the shop or owner installs the engine.
My own 3.0, which I built is webers and twinplug, soon to be aftermarket FI...I have more experience with aftermarket FI, and I usually only use new injectors.

[proporsche]

[QUOTE=Mark Henry;12138842]I ran into a friend, long time Porsche wrench, he also suggested injectors. Didn't think of this as owner said they were just rebuilt locally, but he said many "rebuilders" are hacks. I'm going to check this first.

I've rebuilt many stock and mod engines and never had issues with cam timing, and used a kirk valve adjustment tool. I've done top ends and studs on 3.2's before, as I rebuild engines...just never installed a 3.2 into a car. Most of the time I get the longblock, do my thing and the shop or owner installs the engine.
My own 3.0, which I built is webers and twinplug, soon to be aftermarket FI...I have more experience with aftermarket FI, and I usually only use new injectors.[/QUOTE

i had a feeling you know what you are doing.....i had to ask....
so you did the engine and after the car got to you to install it,right?You did not take the engine out,i assume...
I would check your fuel pressure..if the person somehow blocked the fuel line,either in or out..since the car was sitting...

Ivan

[wazzz]

2, 4, and 6 are run in sequence (actually 6, 2, 4). May be a coincidence, but worth noting.
Have you tried to wiggle the injector 4-terminal connector on the front left of the engine, behind intake?
Also, may be I'm wrong, but I would check the distributor itself, in particular its centrifugal mechanism.

[spuggy]

Originally Posted by wazzz

2, 4, and 6 are run in sequence (actually 6, 2, 4).

3.2 injectors are batch-fire. All injectors fire at the same time if any injector fires, regardless of stroke.

You need a cam position sensor for sequential injection. The 3.2 doesn't have one.

[mysocal911]

Originally Posted by spuggy

3.2 injectors are batch-fire. All injectors fire at the same time if any injector fires, regardless of stroke.

You need a cam position sensor for sequential injection. The 3.2 doesn't have one.

He knows. He's referring to the firing order;



"2, 4, and 6 are run in sequence (actually 6, 2, 4)"

[john walker's workshop]

Did you clean the injector plug on the rear shock crossmember?

[prschmn]

Bad dizzy bushings? And maybe try moving injectors to see if the problem follows,guessing you have checked all six are getting a signal-and the plug as John has mentioned .

[proporsche]

any updates M.H??

Ivan