Matt Sheppard

OK

Cranks over real strong (not factory alarm stuff getting in the way, right?)

Smell fuel in tailpipe (not DME relay since pump is working, right?)

Test light shows power to + and - side of the coil when key is on, right?. . .

so no go, not even a sputter. This is my daily driver and I'm stuck at work.

Any help?

nh3

Check the connections on the speed/reference sensors. Also check the resistance on the sensors themselves if the connections don't work for you. Sorry I don't have the values handy now.

nh3

MHT

try tapping on the ECU while you crank. Sometimes the connections to the ignition driver in the computer crack, cracked solder joint, just like the DME relays. If the car starts when you tap on the computer then this might be your problem. If it is the problem, E-mail me and I can tell you how to fix it.

Bri Bro

Question, if the coil is pulsed by the DME, why would you see a connection across the coil without cranking the engine? The coil has a hot connection on one side and the DME pulsed connection to ground (when spark is required) on the other. Are you measuring directly across the coil?

Luis de Prat

FWIW, I had a no-spark no-start situation in my S2 recently, and it WAS the factory alarm control unit causing the problem.

When you say "cranks over real strong," is the engine doing anything, or do you just hear the starter?

If the problem is electrical, you can bypass it by bridging the poles for the DME relay so that fuel is sent to the engine regardless of the DME/alarm situation. IIRC, you need to bridge the three large poles with a decently wrapped wire and spades.

Good luck.

Matthew West

Pull a plug wire and put a spare spark plug in it. Ground the plug to the block and check for spark that way. I had the same problem and it was a rotor that had lost the set screw. The cam spun, but the engine was not getting spark. Also you should verify spark to two cylinders to rule this out.

Matt Sheppard

Hi all

Thanks for the contributions. I had to leave the car at work last night and have my wife come and get me. Not good P-car PR to the family when my "reliable" daily driver doesnt function.

I think nh3 has got the right track: If memory serves me correctly, some of you have had speed ref. sensor problems in the past after driving in the rain? Well, we had crazy rain (not snow, . . .RAIN <img border="0" alt="[grrrrrrr]" title="" src="graemlins/cussing.gif" /> ) the past week for 3 days solid and I think it's that same problem.

What happens in this situation? The connections get waterloged? I have a plan to go back today w/ a heat gun and dry them out and fiddle w/ them. I think this is it. Anyway to prevent such in the future?

Luis:
If the alarm is the culpret (non functioning since I never had a key- i.e. in "off" pos. on the keyway), wouldn't the engine not turn over w/ starter? I smell gas definately at the tailpipe too so I imagine DME relay not to blame, right?

FYI: I pulled the cap off to inspect the rotor as I've had one break on me before, it was fine. I had a spare DME and KLR w/ autothority software that I plugged in with no difference- just happened to have these in the car at the time <img border="0" title="" alt="[Wink]" src="wink.gif" />

I did not feel comfortable asking a workmate to come help me fix my car (crank engine while I chased spark) and my wife was pressed heavy for time when she picked me up, otherwise I would absolutely have followed that diagnoses.

Thanks again to all who replied, I will post results later today.

SoCal Driver

With the key on you should have 12 volts to one of the coil wires and to one of the two pins on any injector.

The coil gets it's voltage from the key and the injector gets it's voltage from the DME relay (the key closes the first set of DME relay contacts). The DME also gets it's voltage from the first set of relay contacts.

The second set of contacts that run the fuel pump can only close if the first set has closed. When you crank the car the voltage that goes to engage the starter is also picked up by the DME brain (ECU) and it runs the fuel pump while cranking and for a second after your stop cranking. The fuel pump is then controlled by the DME "seeing" the sensors and will be shut off below 200 rpm.

If you have no spark during cranking but you have a running fuel pump (and a gas smell from your tail pipe) check the high voltage wire from the coil to the dist. cap. These corrode inside the connectors at the ends of the wires and separate from the connector. The rubber weather boot will keep them attached so they look ok. this condition is aggravated by heavy rain getting past the weather boots.

There should be a baffle between the dist cap rotor and the aluminum housing. This keeps the water the timing belt can pick up from flooding the dist.

Danno

The rain is a clue. I was troubleshooting a no-start problem with a guy a couple of months ago. Turned out his alarm box wouldn't give power to the DME relay because it was completely filled with water!!! A leak from the battery box dripped water down his wiring harness into the alarm box...

SoCal Driver

The factory alarm shuts off both the DME relay and the coil.

Matt Sheppard

Still no go.

While fiddling w/ the refernece sensors, I did notice on of the wires was frayed near the connector that runs into the main wiring bundle down to the DME. I checked this out when I got home on my parts car that has a sensor that's almost disintegrated - made disection easy. It seems these have a steel braided protection sleve guarding 3 wires and that is the steel I saw, not an electrical wire.

My only other option right now is to replace the DME relay and try that.

Danno:
I fiddled with the alarm box when I was switching control boxes, it was dry.

SoCal:
I will chase spark again tomorrow and bring an extra HT lead in case.

Really, thanks again to all, I really value your input.

As a side note
I started pulling the parts nec. to remove my turbo for rebuild (the smokey '87). I got all the plumbing, intake and every bolt off the turbo except for the two under-car mounting screws in under 1 1/2 hours!

Whoever did the exhaust work on this car (Vision Motorsports I presume as they did the turbo) really made things easy using SS hardware. They also speced a turbo using a T-bolt joined down-pipe which made what are usually the worst bolts easy. This means the turbo will be going to Majestic or Turbonetics as soon as Tuesday! Yeah baby.

Matt Sheppard

It WAS the DME Relay, car runs again.

have mixed feelings.
The car runs but I should have known to check that first or second. I have a spare DME relay in the glove box of my '87 all the time, just not in the '86. - Note to self, never leave home without a spare DME relay again!

So, how come I smelled gas?

944Play

</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Originally posted by Matt Sheppard:
<strong>So, how come I smelled gas?</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Leaking injector?