944 spark problem

MixMasterK · 10-18-2001, 08:43 PM

I have an '83 944 that will not produce any spark what-so-ever! I have replaced everything from the coil forward to the spark plugs. Also one of the crankcase sensors was found faulty and I have replaced that as well. My concern is that the problem may lie in the DME unit. Is there a way to test this unit short of having to find another person with an '83 and trying it in their car? Has anyone else had this same problem on their car?

[This message has been edited by MixMasterK (edited 10-18-2001).]

EugeneYu · 10-18-2001, 09:01 PM

Check your timing belt. (Open dis cap, crank engine to see if rotor spins or not, or open tb cover to see what happened behind.)

Britwrench · 10-19-2001, 06:51 AM

First of all you don't need to take the dist cap off to check the timing belt. Just look in the hole above the cap and you will see the pulley and belt.

So what is the actual fault; you say there is no spark..shat happen before that? did the car not start, did it suddenly cut-out,
how was the sensor determined to be faulty?
Does the fuel pump run and injectors
operate?
No start problems can be caused by manu things so always follow a plan.

Replacing parts and guess-work will not find the cause.

MixMasterK · 10-19-2001, 09:59 AM

The sensor was determined faulty by the shop I had taken it to. Basically the cable had a split in it which was exposing the sheilding. Upon bench testing of the sensor, it was giving an intermittant signal. Hence, it needed to be replaced. All the belts and such are fine! They were replaced and tightned at the shop. The problem lies somewhere before the ignition coil as there is no output from the coil. I do have voltage to the coil, however.

Britwrench · 10-19-2001, 10:33 AM

The DME unit is the ground for the ignition system, therefore if you have voltage at the coil but no spark there's a good chance the
DME is faulty. First though check the feed voltage to the DME and check and replace the relay. Try your DME in another car if possible. DO NOT put a DME into your car as
if your car has a short.........

MixMasterK · 10-19-2001, 10:55 AM

What relay is it and where is it located?

Britwrench · 10-19-2001, 11:02 AM

On your car; check the fuse/relay board under the dash on the extreme left side.
It's on the upper line of relays, the second one from the left.
The part# is 944-615-227-00, the updated part# is 993-615-227-00 they cost about $20.
Change them every five years.

MixMasterK · 10-19-2001, 03:37 PM

According to my little spec book, the second relay is the Fuel pump relay. Does this sound like the one your thinking of. If so, it is missing from the relay board.

Britwrench · 10-19-2001, 05:08 PM

It's on the upper row of relays...you have to fold yourself under the dash to see it.

If it's missing it won't start and the fuel pumps will not run. Doubt if missing, just look harder..

Lotsa luck...

MixMasterK · 10-19-2001, 05:53 PM

Nope. It is definetly not there. I have no idea why it is missing. I looked through my wiring diagrams and, sure enough, found that it does go to the DME and without it, it will not run. Thanks for the help. Now as long as the DME is good, I should be ready to roll. I'm going to get a relay on order next week.

By the way, what did they do to the relay as an update? In other words, how did they improve it?

drew1 · 10-20-2001, 08:00 PM

Listen to old BRITWRENCH. It seems to me that hwe gives good advice. Have you checked fuel pressure or tried a noid light on injectors to see if they are firing?

drew1

MixMasterK · 10-21-2001, 04:05 AM

I already found the problem! Don't want to sound rude, but read the replies.

drew1 · 10-21-2001, 04:42 AM

Sorry Mixmaster

T86951 · 10-21-2001, 06:18 PM

what was the problem?

MixMasterK · 10-21-2001, 06:19 PM

THE RELAY IS MISSING!