1985 S2 no start
Burning Brakes
Joined: Jul 2015
Posts: 920
Likes: 140
From: Dorset
I'm all out of ideas. Given you have fuel pressure and working injectors, spark and correct mechanical arrangements for spark timing, the only other thing I can think of is to look for single point failure in the wiring. Might be worth continuity testing wire that the CPS connects to maybe?
Team Owner
Joined: May 2004
Posts: 31,234
Likes: 4,220
From: Philly PA
well your big issues beyond all the wear items was that you were missing one of the right cam tower grounding wire connections,
and if either one is loose or corrupted then the FI system will not function
and if either one is loose or corrupted then the FI system will not function
Rennlist Member
Joined: Mar 2002
Posts: 6,115
Likes: 344
From: Texas
Let's summarize:
Engine ran initially, but only on 4 cylinders due to broken distributor belt.
The battery is fully charged.
The engine turns over.
Spark is present.
Fuel is present, both in the fuel rail and through the injector (ie plugs are wet after cranking)
Compression ranges from 125 to 140.
And the MAF is basically out of spec.
So you have fuel, compression and a spark to ignite it.
Why is it not running?
The fuel is present. It is either there or not
The compression is there
The spark is there, but I think that is where the answer lies. If the spark is not timed correctly, the engine will not run. Something is amiss with the spark I think
Maybe there is something being overlooked in your testing that we are taking for granted. (Such as cylinder numbering: #1 is the front cylinder on the left side looking at the engine, numbers 2-4 are behind that with #5 front right and 6-8 behind that)
Something that easy could be screwing this up.
That's why I was adamant about the relays and checking those. If the engine ran even on 4 cylinders before with the replacement CE board, it should be running now.
How about the factory alarm? Have you locked and unlocked everything with the long key?
Just cogitating here and trying to help.
Engine ran initially, but only on 4 cylinders due to broken distributor belt.
The battery is fully charged.
The engine turns over.
Spark is present.
Fuel is present, both in the fuel rail and through the injector (ie plugs are wet after cranking)
Compression ranges from 125 to 140.
And the MAF is basically out of spec.
So you have fuel, compression and a spark to ignite it.
Why is it not running?
The fuel is present. It is either there or not
The compression is there
The spark is there, but I think that is where the answer lies. If the spark is not timed correctly, the engine will not run. Something is amiss with the spark I think
Maybe there is something being overlooked in your testing that we are taking for granted. (Such as cylinder numbering: #1 is the front cylinder on the left side looking at the engine, numbers 2-4 are behind that with #5 front right and 6-8 behind that)
Something that easy could be screwing this up.
That's why I was adamant about the relays and checking those. If the engine ran even on 4 cylinders before with the replacement CE board, it should be running now.
How about the factory alarm? Have you locked and unlocked everything with the long key?
Just cogitating here and trying to help.
Rennlist Stories
The Best Porsche Posts for Porsche Enthusiasts
9 Features and Characteristics That Only Porsche People Understand
Verdad Gallardo
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way
Joe Kucinski
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)
Verdad Gallardo
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner
Joe Kucinski
This Builder Is Turning Heads With Its Slantnose 911 Creation
Verdad Gallardo
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture
Verdad Gallardo
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Verdad Gallardo
10 Porsche Colors That Have More Personality Than Most People
Verdad Gallardo
Guntherwerks' Final Speedster Creation Is the Ultimate Porsche Restomod
Verdad Gallardo
Rennlist Member
Joined: Feb 2002
Posts: 7,060
Likes: 42
From: Cambridge England
That doesn't mean there isn't a timing problem.... After removing the old belt, did you rotate the engine ? It might be possible to use a pressure gauge on cyl 1 to confirm the firing stroke and whether the distributor is clocked correctly.
Thread Starter
Advanced
Joined: May 2020
Posts: 50
Likes: 0
Well firstly I have to say thank you for all your help and suggestions. This has been an interesting journey. Now I won't keep you in suspense...
It starts!!!
Back to basics. From experience it really did sound like a spark timing issue. I aligned to TDC and scraped off the blobs of tippex (white paint) from both camshafts to reveal no timing marks. So, a previous owner or mechanic had changed the belt with the engine 180° out. I aligned the cams correctly, refitted the distributors correctly and she fired straight up.
Sorry for the long journey, in hindsight, I should have double checked this... At least the other suspect components have been replaced on the journey and I know that every sensor is working in spec
Now I need to work out why the speedo doesn't work.
Regards
Simon
It starts!!!
Back to basics. From experience it really did sound like a spark timing issue. I aligned to TDC and scraped off the blobs of tippex (white paint) from both camshafts to reveal no timing marks. So, a previous owner or mechanic had changed the belt with the engine 180° out. I aligned the cams correctly, refitted the distributors correctly and she fired straight up.
Sorry for the long journey, in hindsight, I should have double checked this... At least the other suspect components have been replaced on the journey and I know that every sensor is working in spec
Now I need to work out why the speedo doesn't work.
Regards
Simon
Thread Starter
Advanced
Joined: May 2020
Posts: 50
Likes: 0
Thread Starter
Advanced
Joined: May 2020
Posts: 50
Likes: 0