Oh No she won't start again

[jonnyporsche]

Anyone who followed my last saga www.porscheclubgb.com/forum/tm.aspx?m=932044#951514 will know I had a starting issue last year. well I sorted the problem (I thought) as I got her running upto temp. bled the cooling, checked the fans were coming on etc. I thought while she's up on stands I'll tidy up the underside a tad. I found a very small area of rust in the front of the offside sill behind the wing liner under the ABS pump so welded a small patch. Now she won't start. Have I fried the DME is the question? battery was disconnected but I forgot to remove the relay or disconnect the DME.
Long story short she ran fine after replacing both ref. sensors, FPR and return fuel line.
I'm getting fuel but no spark. Anyone have any ideas please.

 

[944 man]

I would say that there is a reasonable chance that you have. The established way to test used to be to replace with a known good DME, but the recent increase in values and asking prices in particular, means that people are just making up prices for 951 DME/KLRs now.

Specialists used to keep DMEs to use to test. If you cant come up with one then Id take both out and have them tested by an ECU repairer - the trade-off being that if they're refurbed then you know that they are good. I have the details for a repairer somewhere, but I have three computers on this desk alone and I'm not sure where their link is...

 

[PhilKent]

I'm guessing you've swapped out the DME relay to remove that from the equation already? If not that's the first port of call I would say. I always carry a spare in the glove box. Had a similar issue myself a couple of days ago, was about the swap out the relay but hey presto, I got a spark, replaced the dizzy cap and of we went... Next check the earth strap on the engine...noddy stuff I know, sorry I'm probably being of no use!

 

[jonnyporsche]

I would say that there is a reasonable chance that you have. The established way to test used to be to replace with a known good DME, but the recent increase in values and asking prices in particular, means that people are just making up prices for 951 DME/KLRs now.

Specialists used to keep DMEs to use to test. If you cant come up with one then Id take both out and have them tested by an ECU repairer - the trade-off being that if they're refurbed then you know that they are good. I have the details for a repairer somewhere, but I have three computers on this desk alone and I'm not sure where their link is...

New coil, still no go. is the bounce on the rev counter thing a definitive that the sensors and DME are ok?

I have come across www.augmentautomotive.co.uk/ecu-repair-service/ anyone any recommendations

 

[peanut]

have you had any progress yet Jonny ?

Have you fitted a 3x wire DME relay bypass yet ?

The bypass not only supplies power to the fuel pump it also supplies a permanent 12v+ supply to the ECU which pulses your ignition control module too.

If there is no spark at the coil but you have fuel it would suggest that the ECU is probably OK .(It is reverse polarity and surge protected.)

Next easy step would be to either test the ignition control module (ICM) or substitute a known good one .

The ICM takes the low voltage ignition pulses from the ECU and amplifies them to provide timed HT to the coil and plugs

 

[jonnyporsche]

have you had any progress yet Jonny ?

Have you fitted a 3x wire DME relay bypass yet ?

The bypass not only supplies power to the fuel pump it also supplies a permanent 12v+ supply to the ECU which pulses your ignition control module too.

If there is no spark at the coil but you have fuel it would suggest that the ECU is probably OK .(It is reverse polarity and surge protected.)

Next easy step would be to either test the ignition control module (ICM) or substitute a known good one .

The ICM takes the low voltage ignition pulses from the ECU and amplifies them to provide timed HT to the coil and plugs

Thanks peanut for your input. I still haven't got her going yet (struggling a bit with time at the moment) I haven't totally ruled out fuel and plan to do a pressure test but I am fairly convinced that the problem is electrical.

What I haven't mentioned is that when first attempting to start the engine after the welding it did fire once and immediately died as if something had fused if that helps.

I will follow your suggestion, where will I find the ICM and how do I test it? unfortunately electrics are a bit of a dark art to me but I am trying to learn.

 

[peanut]

ICM is fixed to the wheel arch under the bonnet on the passenger side .

 

[jonnyporsche]

New development after a bit of connection twiddling yesterday she started and stayed running up to full temp. So did oil and filter change and put her back on the ground, Now she's gone back to intermittent starting and then stalling which was the start of the original problem, I'm convinced that the problem is something simple that is breaking down so will need to keep looking and checking, Thanks peanut for the input will have a look for the the ICM but I am sure I read somewhere that the Turbo doesn't have but I could be wrong.

 

[Eldavo]

No ICM on a turbo.

Have a wiggle of the crank sensors, friend had a similar problem and they were loose/not grounding.

 

[jonnyporsche]

No ICM on a turbo.

Have a wiggle of the crank sensors, friend had a similar problem and they were loose/not grounding.

Will try anything. Does Nick Knowles do DIY 944 SOS [][][]

 

[Frenchy]

Distributor cap, check the female sockets to the plug leads for any corrosion or crap, if that looks okay take it off and check along with the rotor arm.

 

[vitesse]

I've got 2 used crank sensors recently replaced on my Wife's 924S when we changed the clutch-were working then but thought worthwhile changing them whilst the job was being done-I have posted already about them -one has a slightly damaged Bosch connector but will still connect & work-welcome to have them both for £5 including postage.

I bought the new ones from GSF(have used them before for my red 924S)-2 new ones (not OE-but known brands) cost me £80 c/f £ 175 or more from OPC-still working very well.

 

[jonnyporsche]

Distributor cap, check the female sockets to the plug leads for any corrosion or crap, if that looks okay take it off and check along with the rotor arm.

I've got 2 used crank sensors recently replaced on my Wife's 924S when we changed the clutch-were working then but thought worthwhile changing them whilst the job was being done-I have posted already about them -one has a slightly damaged Bosch connector but will still connect & work-welcome to have them both for £5 including postage.

I bought the new ones from GSF(have used them before for my red 924S)-2 new ones (not OE-but known brands) cost me £80 c/f £ 175 or more from OPC-still working very well.

Just fitted 2 new crank sensors and the dizzy cap, rotor and leads are about 200 miles old. Still scratching my head.

This weekend if time allows I shall check the leads from the crank sensor connections to the DME and KLR, earth connections, fuse box connection and whilst in the foot well the immobilizer.

 

[jonnyporsche]

Now my computer is having a fit sorry about the repetition I can't delete them [:'(][:'(][:'(][:'(]

 

[tscaptain]

I think it may be the operator rather than the computer. Are you clicking on "submit post" multiple times because it seems that it hasn't worked the first time?

 

[jonnyporsche]

I think it may be the operator rather than the computer. Are you clicking on "submit post" multiple times because it seems that it hasn't worked the first time?

Thanks for sorting this out []

 

[jonnyporsche]

So for the few still following this saga here is an update. I decided to replace the few bolt on bits left that I haven't replaced, so a new coil made no difference, next was sending the DME and KLR to https://www.augmentautomotive.co.uk/ecu-repair-service/ for service, some dodgy soldering in the DME was found, in the mean time I replaced the fuel pump. Now all back together another HOORAY she started, stayed running and re started ok. I think I've cracked it [][][] now just need to bleed the brakes and head for the MOT centre. It's only taken a year.

 

[944Scott]

Quick get out and drive it lots before the weather changes []

 

[jonnyporsche]

Quick get out and drive it lots before the weather changes []

Yes thats the idea I've been waiting a year [][][]

 

[jonnyporsche]

Quick get out and drive it lots before the weather changes []

Yes thats the idea I've been waiting a year [][][]

Update [] M.O.T. pass no advisories [] New problem now [] She blows out blue smoke like a WW11 destroyer when on boost [] So any tips on removing, refurbishing, or replacing the turbo, as it looks like its been there for 30 years, would be gratefully received []