S2 lost power funny exhaust noise, Help

Waylander · May 25, 2015

any old spark plug lead will do just for a test,

or your local motor factors for a spark tester just to confirm its got or not got a spark.

Monkeythree · May 25, 2015

Yep. Just borrowing a known good one from another cylinder will give you a pretty much instant answer as to whether no.2 lead is bad or not.

Or if you are feeling masochistic, simply take a firm grip of no.2 lead in your hand and have an accomplice turn the engine over. You will soon know if the spark is leaking out of the lead! [

]

(No liability accepted for death or injury if you are foolish enough to use the above method) [

]

jamieda · May 25, 2015

haha brilliant, i could ask someone "hold that a moment mate"

ORIGINAL: Monkeythree

Yep. Just borrowing a known good one from another cylinder will give you a pretty much instant answer as to whether no.2 lead is bad or not.

Or if you are feeling masochistic, simply take a firm grip of no.2 lead in your hand and have an accomplice turn the engine over. You will soon know if the spark is leaking out of the lead! []

(No liability accepted for death or injury if you are foolish enough to use the above method) []

jamieda · May 25, 2015

Fitted new ones on Saturday, the old ones were shot to bits.

ORIGINAL: Fred Hindle

http://www.eurocarparts.com/ecp/c/Porsche_944_2.5_1988/b/Bosch/p/Car-Parts/Engine-Parts/ignition1/ignition-lead

Maybe a good idea to change the rotor arm and the dizzy cap while you are about it unless they have been done recently.

Cheers,

jamieda · May 25, 2015

i don't know if this means anything but I've just done a resistance test with a multimeter and all the ignition leads were reading the same?!?! not sure if this means anything.

(turns out its cylinder 3 not 2 DOH i was counting from the wrong end)

I put the lead from cylinder 4 into cylinder 3, cylinder 3 lead would not reach cylinder 4 (all the leads are the right length to fit each plug)

So i tried to start the car with just 1,2 and 3 attached, it wouldn't start at all?

Monkeythree · May 25, 2015

Take the plug out of the suspect cylinder and plug it back into its suspect lead. Earth the body of the plug against a convenient earth (engine lifting eye is good). If necessary, secure the plug against the convenient earth with mole grips or similar. Turn the lights out. Turn the engine over and keep a close eye on the spark plug gap. You should be able to see a nice bright blue spark jumping across the gap. Report back what you find.

jamieda · May 25, 2015

Spark - http://youtu.be/-I6t_CGWVF0

Compression - https://youtu.be/zh3hm-f5D4c

Got spark and compression confirmed, piston head is wet but i guess this doesn't confirm fuel coming in. how do i do that?

Thanks for the help Monkey

ORIGINAL: Monkeythree

Take the plug out of the suspect cylinder and plug it back into its suspect lead. Earth the body of the plug against a convenient earth (engine lifting eye is good). If necessary, secure the plug against the convenient earth with mole grips or similar. Turn the lights out. Turn the engine over and keep a close eye on the spark plug gap. You should be able to see a nice bright blue spark jumping across the gap. Report back what you find.

Monkeythree · May 25, 2015

So you have a spark at the suspect cylinder. Suggest you quickly check the others just to be sure you have 4 good sparks.

So while you were doing that test on the suspect plug lead, did the engine sound the same or different to when it was running roughly but with all the plugs in and leads connected? (Sounds the same to me but would be good to know if you detected any difference).

If sparks are all good and compression all good it is starting to look like a fuelling issue.

Waylander · May 25, 2015

some one with a bit of mech know how must be close to you, come and give you hand

JamesO · May 25, 2015

Stuck injector flooding the cylinder?

944Scott · May 25, 2015

Did you revert back to using the plug lead from cylinder three when checking for spark or were you still using the plug lead from cylinder four ?

Monkeythree · May 25, 2015

ORIGINAL: 944Scott

Did you revert back to using the plug lead from cylinder three when checking for spark or were you still using the plug lead from cylinder four ?

Very good point. It would be good to be certain of this before moving on. Jamie?

jamieda · May 25, 2015

ha, i reverted back to using plug lead 3..... good call though.

when i was testing the plug the engine sounded exactly the same.

i guess its time to look at swapping the injectors over see if that makes a difference.

Monkeythree · May 25, 2015

I would start with a close visual examination of the injector wiring going to number 3 cylinder. Check for any signs of chafing of the insulation on the wires or any obvious kinks or tight turns that might have turned into a break.

jamieda · May 25, 2015

none of us (my mates) have any knowledge of this kind of thing.

I bought this car to drive and fix, its my learn about cars car, both how to drive on track and fix, I've always wanted to learn about the mechanics of a car so i'm enjoying this.

ORIGINAL: Waylander

some one with a bit of mech know how must be close to you, come and give you hand

jamieda · May 25, 2015

I've got to say the bend in the wiring going to injector 3 is very tight but doesn't look broken.

Can i swap the electrical connections over from one injector to the next or is that running the timing?

ORIGINAL: Monkeythree

I would start with a close visual examination of the injector wiring going to number 3 cylinder. Check for any signs of chafing of the insulation on the wires or any obvious kinks or tight turns that might have turned into a break.

944Scott · May 25, 2015

For the record, where in the country are you located ?

Monkeythree · May 25, 2015

ORIGINAL: jamieda

I've got to say the bend in the wiring going to injector 3 is very tight but doesn't look broken.

Can i swap the electrical connections over from one injector to the next or is that running the timing?

ORIGINAL: Monkeythree

I would start with a close visual examination of the injector wiring going to number 3 cylinder. Check for any signs of chafing of the insulation on the wires or any obvious kinks or tight turns that might have turned into a break.

Click to expand...

You can't swap the injector wiring over because they are sequenced to the engine firing order.

The tight bend might not look broken from the outside. Get all your plugs and leads back on and start it up again and give the injector wiring a good massage along every part you can get your fingers and thumbs around and listen carefully. If there is break and you manage to get a contact whilst massaging the wires, that cylinder should kick back in again and you will surely hear the difference in the running.

jamieda · May 25, 2015

Walton on Thames
Surrey

ORIGINAL: 944Scott

For the record, where in the country are you located ?

jamieda · May 25, 2015

Thought so, ok will give that a go tomorrow when i get back from work.

Will report back.

cheers, really appreciate the knowlage

i have no problem chucking this in to a Porsche specilist to sort out but that would be cheating and defeat the object.......... so thanks again for your time.

ORIGINAL: Monkeythree

You can't swap the injector wiring over because they are sequenced to the engine firing order.

The tight bend might not look broken from the outside. Get all your plugs and leads back on and start it up again and give the injector wiring a good massage along every part you can get your fingers and thumbs around and listen carefully. If there is break and you manage to get a contact whilst massaging the wires, that cylinder should kick back in again and you will surely hear the difference in the running.