ekmxryda

Looking for help with thoughts to get this 68,000 mile very clean, no rust, no water damage, 1988 951 Silver Rose back on the road after previous owner left in garage for ten years.
Have been reading posts on Rennlist for the last month and it has been very helpful. Also ran a bunch of tests from Clark's Garage. Went through fuel system first, drained tank and cleaned pick up screen, replaced line to fuel pump, fuel filter, and blew out lines. Sent fuel injectors out to be cleaned and flow tested, checked line pressure at 36 lbs and leakdown test held well.
New battery, spark plugs, checked cap and rotor plus the set screw and they look ok. Turns over fine but no spark. Checked grounds, all fuses and relays. DME relay is fine with proper voltage at pin 30 and 86, 12V at injectors. Was getting tach bounce while cranking over but after reading a bunch of posts on bad speed and reference sensors I went ahead and replaced them. Have 12V at Coil positive and negative posts, still wasn't seeing output from Coil. New Coil installed acts the same. Checked DME plug and pin 4 (start signal) is only 10.5 V while cranking. 12 V on pin 1 (ignition pulse to coil), and pin 18. The car had a Clifford alarm at one point but I cant find any signs of it now. Factory alarm relay G18 was missing from the fuse box. If it was an alarm issue would I be getting 12 V at the pin 4 on DME plug? I am wondering if it is a bad DME? Or just a break in the harness somewhere, I am not the best at electrical troubleshooting so forgive me if I have missed something obvious.
Any other quick tests I could run before sending off DME for service?
Thanks, Eric

Jfrahm

This thread might help.

https://rennlist.com/forums/944-turb...989-951-a.html

Otherwise where are you located? Maybe someone nearby has a spare DME/KLR

ekmxryda

Thanks Joel, I will check out that alarm bypass. I am just north of Boston Mass if anyone has a spare DME / KLR to try out.

GPA951s

There also could be a problem with the airbag module, The power is sent Through the airbag module so In the event of deployment it shuts the car down, To test, unplug the big round connector and jump pins 3 and 4.. Might be worth a try...

ekmxryda

Ok good to know, I can check the airbag module tomorrow thanks.

ECU Doctors

ekmxryda

Any luck with this yet?

Is there fuel pressure in the lines?

Do you have injection at least?

ekmxryda

Hi I do have good fuel pressure 36lbs and leakdown test held.
Sent injectors out for cleaning and flow test, have 12 V at injectors.

I have not had a chance to work on the car, hope to this week.
Need to rope in some help somehow, feeling lost.

Thanks,
Eric

ECU Doctors

Ok so fuel pump is good.

Can you confirm that you have injector pulse? Can you smell fuel after cranking the car?

Is yes, then your sensors are fine, but 1 of the 2 Control units (DME or the KLR) is not working properly.

ekmxryda

Yep smell fuel after cranking over. Could just be a leak though!
Friend said he would let me borrow his Noid light set to test to make sure they are firing.

Along the same lines as the Airbag Module, just was wondering if a bad Turbo water pump relay could keep the DME from firing?

ECU Doctors

No it wouldn't keep if from running as far as I know.

The noid light test results will be great info once you have it.

PerryB

ekmxryda,

When you replaced the speed and reference sensors, what brand did you use?

GPA951s

Are the ref sensors Gapped Correctly? Were they done one at a time? connectors switched.. ?

ekmxryda

Hey guys,

Used FAE sensors, made sure to mark connectors so I wouldn't swap them by mistake.
Wiring was good, checked pins on DME plug.
Used same spacer that was there so gap should be good.
New coil checks out ok, followed Clark's coil test procedure.
No voltage out of coil when cranking.
Injectors firing.

Pretty sure I have checked all the grounds?
Have not looked at the Air Bag Module yet. Looking for that info...

http://www.paragon-products.com/Pors...606.115.00.htm

Jfrahm

I doubt if the airbag module shut things down it'd allow the injector pulse.

Here is a KLR bypass thread:
https://rennlist.com/forums/944-turb...lr-bypass.html

Some pretty good troubleshooting here too:
http://forums.pelicanparts.com/porsc...r-problem.html

...also verifies jumpering the pins to run w/o a KLR.

-Joel.

ekmxryda

Hi Joel,
Thanks for the links I will check them out, more great info!