Johnny G Pipe

Hi folks, only here when I want something

I did a 12k service, (valve job, oil and filter, air and fuel filter, plugs - correct Bosch ones) and also removed my a/c condenser, plugged off the lines (have given up on the a/c for now), and tidied up some tinware at the weekend.

The car ran great afterwards, smooth, powerful -but about 12 miles later coughed, spluttered and died, would not restart. Turns over really well, kind of fires but not really enough to run. No warn lights, no horrible noises, no smoke or oil leaks. I noticed the spoiler had stayed up after it died but it probably missed the speed signal as it cut out.

I didn't overfill it and was very careful doing the valves and rechecking..they were all mainly in spec anyway.

I have done the following:
Recheck plug leads all seated correctly.
Tried Spare DME
Jumpered DME, fuel pump sounds alive and well.
Checked distributors, rotor arms and toothed belt, all good.

I guess I am going to go down the troubleshooting route, checking I have fuel and spark, coils, flywheel position sensor and so on. But, is this is too much of a coincidence to not be related to the service.. Hence my question: anybody have any suggestions as to what could have happened in the course of the service? Any experience of this? Any gotchas with the fuel filter or something?

This is the first time she has stranded me in 13 years.. the only thing that cheers me up is that I probably did something wrong to cause her to fail me!

Thanks in advance..

Earlydays

Check your battery connections, especially the ground wire....

justin-in-athens

Sounds vacuum related, check the main crankcase breather on the backside of the motor...that is what mine was in this exact scenario.

Also grounds as suggested above.

Johnny G Pipe

Thanks guys, will check these things.

One of the rotor arms was looking a little tired, and when i swap the arms between the two distributors the car starts, but runs rough. Hopefully this is a sign of the source of the problem, and the failure right after the service is coincidence after all (or maybe the plug wires were so well seated up against the plugs that a weak spark could get across, but not now they have been disturbed..?)

Anyway. New caps and rotors ordered. Not wanting to get into the expensive diagnose-by-replacement of parts, but caps/rotors is a service item at least, and I have no local specialists I can call on..

Cheers

Richard Curtis

Check that the coils are producing a strong enough spark, which you can do by merely observing the color of the spark at the plug. Should be bright blue. If any other color -- yellow, red, orange, etc. -- you've got a weak coil(s).

Johnny G Pipe

Thanks. The new rotors/caps hasn't helped.

Testing coils is by removing a plug and grounding it against the engine case and turning it over, looking for a strong spark, correct?

(Although if there is no spark at all, I realise could be many causes..)

justin-in-athens

Check the plug to the back of the AFM. Check ICV/ISV for proper operation.

If you give it part throttle while attempting to start her, what happens?

Johnny G Pipe

Thanks. Have checked ISV, and scooshed with carb cleaner for luck. Have checked all connectors, vacuum lines in that area.

If throttle added when starting, not a lot extra happens.

I am short of time currently, and I can't get the car into my garage if it won't run! So it is a little frustrating not to have time to get into it. Hopefully this weekend.

I pulled a plug and it looked oily. Don't shoot me but I put a touch of oil on each plug thread when installing. It was the tiniest touch but I wonder if after a little running time this oil found its way onto the electrodes of a few of the plugs and has fouled them. Will pull all the plugs this weekend and clean and reinstall to double check this.

18T_BT

If you hold the gas pedal down all the way (not letting it go) while cranking will it start and run rough and die as soon as you let go of the gas pedal? Sometimes a couple of blimps of the throttle aren't enough when you may have a big vacuum leak.

Johnny G Pipe

Ok, in the search for quick fixes.. briefly swapped the leads between the coils and she has started! Runs fine..but doesn't make sense to me as the dist drive belt is intact and both rotors turn with the engine.

What does it mean?

But in the meantime, yipee! Really tought this had the makings of a long expensive story punctuated by confusing multimeter readings and me breaking more stuff as I fumble about. :-)

Thanks for the help..and in conclusion looks like this was just a coincidence and nothing to do with the service after all. Good.

Vandit

When you're isolating the distributors, do so by disconecting the ignition modules.

jimq

Maybe there was corrosion on the coil connector and one/both weren't getting good contact

justin-in-athens

The primary distributor turns the secondary dizzy by way of the belt, so if the coil or ignition module below it has failed the system would not run.

However, by switching the good coil onto the primary dizzy you can once again run the car. The car can be run in this fashion but it will be down on power as you are really running on six plugs instead of twelve.

Johnny G Pipe

Hey Jason.

I am on my second celebratory trappist beer, and so forgive me..surely the drive to the primary distributor/lower plugs is mechanical, and linked mechanically to the secondary distributor by the belt? So if only one coil or ignition module has failed, the car should still run on either the upper or lower bank of plugs?

In my scenario I wonder if I have a bad HT connection in either the upper or lower bank, AS WELL AS a bad coil/ignitor - so that I needed the good coil and the good plug bank matched to make the car run..?

Won't have time to investigate more until tomorrow..