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has anyone converted a 944s to a 250 turbo?

Elliot

Elliot

New member
I need a bit of input please

I have just converted a 1987 944S into a 944 turbo with 250 BHP turbo engine, lsd gearbox, turbo engine loom, ecu and klr etc.

I am currently getting no spark and suspect that the wiring for the ignition amplifier is causing a no pulse output to the coil.

Has anybody done one before and if so do you have any wiring info for the 14 pin plug adjacent to the fusebox please

cheers
 
Haven't got any experience with 2.5 n/a to turbo conversion. But I had a few similar no spark problems with my S2 after I re-fitted my engine.Turned out to be the ignition amplifier thing behind the passenger headlight. A combination of bad connections and corroded terminals.
 
Are you trying to use some of the S's original wiring? Because of the differences between an S's DME and that used in any 8v car, Id try to use everything from the 951.
 
Colin

thanks replaced ignition amplifier

Simon

yes using S original cabin wiring which includes ignition amplifier and 14 pin connector but using turbo engine bay and ecu loom which allows for turbo ecu and klr

I suspect the pins in the 14 pin connector need changing around to match the turbo connector and the connector on the ign amplifier need blanking and rerouting to allow current to pass.

 
The turbo ecu has the ignition amplifier internally, you cannot use an external amp. you need to convert the coil wiring to the turbo setup. i wouldnt be surprised if you have fried something...
 
Oh dear. Id try to use everything from the mechanical donor car., presuming that it is still available. Hopefully nothing too expensive has been damaged.

I did know a relaible Bosch DME repairer, but I cant find their details anywhere... I think that there are far more people offering to repair DMEs than there are people who you should trust. Tom Barks may well be able to repair standard kit, too.
 
I have recently had the 'non starter' problem - cranked but no spark or pulse to the injectors. My car is a 2.5NA converted to a 2.8 turbo running on Motec. So, most things (Clarkes garage etc) were not directly related to my car and therefore not necessarily useful. The mechanic found the crank sensor to be mis-reading (still no starting) the cam sensor was misreading (still no start - notice how things have got a bit 'non-944'?) coil pack OK, earths OK... so he started working through the wiring (whilst I prayed it was not the Motec unit that had failed). The engine loom is new and now interacts with the existing car loom. This is where the problem lay. 2 faulty connectors (yes, 2) the first of which did not cure the issue but fixing the second as well appears to have fixed it. He is now going to fit an additional fuse box to marry the 2 systems together.

With all that said and done (I'm bracing myself for the bill!) I found this list somewhere as a checklist for non-starting cars so I'm sharing it with you in case it sparks some ideas (sorry - couldn't resist the pun... there I go again!).


Here is a list of some test you should do one by one and eliminate problems.
Air/fuel/spark/compression
start by making sure we have a battery that is in spec.
all fluids topped off
no obvious broken wires and all vaccum hoses intact on visual inspection.
OK we have 12v at the battery with adequated cranking voltage we get in and turn the key.
12v from battery to ignition switch
12v from pin 50 on switch to pin 4 on dme plug (start signal)
12v on pins 1 (ignition pulse to ign. coil) and 18 (to G5 dme relay power supply)
12v pin 30 at dme relay (fuel pump power supply)
12v to pin 86 at dme relay in the run position (primary coil voltage)
12v to coil + black wire to ground 12v to - (green wire) to ground
12v to one side of the injectors
All ground contacts are clean
Fuel pump will run if dme relay is jumpered 30/87/87b
Fuel pressure at the rail is 29psig +/- 3 (jumpered 36 psig)
20 minute leakdown not under 14.5 psig
Fuel flow rate is 28oz after 30 seconds
Ignition coil primary resistance across + and - is between .4 and .6 ohms
Secondary resistance is between 5000 and 7200 ohms
Ignition wires are good no cracks or splits including coil wire and seated
Plugs are properly gapped
Ignition rotor is seated correctly with the set screw
Timing belt is installed correctly
Firing order is correct - 1 - 3 -4 - 2
Reference sensors are gapped correctly with .8mm clearance off the flywheel
Reference and speed sensors resistance checks in spec pins 8 and 27 speed 600-1600 ohms and pins 8 and 23 >1m ohm
Reference and speed sensors voltage checks 2.5 and 2v on oscilliscope (good luck)
Reference and speed sensor wiring is not broken at connector to sensor or to dme

Best of luck - these issues can be hellishly frustrating.
Mick
 
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