White Lightnin'

BOSCH #0.227.100.124

Mine are also marked with a "MTR03 250" number.

They each control 4 cylinders... not 1 or 2... TWO cylinders on EACH side of the block.

A module that is in the process of going bad has shown intermittent outage of it's respective 4 cylinders... then quits for good.

Maleficio

What's your exhaust vapors smell like?

namasgt

The exhaust gasses seemed ok I did not or could not smell anything that would suggest raw fuel in the engine bay or in the exhaust gasses.

Mrmerlin

take a peek at the cats if they are glowing orange shut off the car and keep parked outside till things cool off
This is how the 928 can catch fire.

NOTE if this car is an auto then running on 4 cyls has been a known cause of snapping the drive shaft

namasgt

Stan,

There are no cats on this car, the system was removed when I installed the X-pipe, didn't go with high flow cats. I am not driving the car until I figure out what is wrong with it. And yes its an Automatic, so the drive shaft may have been damaged....

killav

Ali,

I have two known good ignition module/final stages we can swap in tomorrow.

I also have good clean 19lb injectors we can swap in, even though I think you said you have your stock ones as well.

We can also put back in your stock LH chip if you would like.

John has lots of spare plug wires, I think we should swap #4 and #7 out and see what happens. I also think we should swap out that distributor cap and rotor for a known good one despite how new they are (30k miles) since they problem cylinders both run to that distributor cap.

John has a spare MAF, lets get our hands on that too. Even though it seems like specific cylinders having issues, it can't hurt.

namasgt

Hey Mike,

I will visit you tomorrow, I just want to swap the modules first and see what happens.

Thanks

the flyin' scotsman

I installed a full set of Ford injectors on a 87 S4 I worked on resulting in exactly the same symptoms you have......bogging and bad vibration/shuddering.

Swapped in new 19lb FIs.........perfect, no running issues.

The Ford units were refurbed/cleaned units.

soontobered84

Ali,
When you and KillaV get together, give me a call. I have a bunch of spark plug ends, an extra spark plug wire set, the extra MAF, injectors, and a used distibutor cap that I will bring as necessary. I do have an extra ignition final stage, but I would have to find it, and I'm not sure how old you guys want to get waiting for me to find it.

namasgt

Today I unplugged each of the modules on the front drivers side to see how the engine responds, while it was idling. It felt terrible when I undid each one. There is no way my car was running on 4 cylinders when I decided to drive it back home. It sounds more like running on 6 cylinders at idle and at around 2000 RPM it feels normal.

Just right now I installed a pair of used known good Bosch ignition modules, with no changes in the condition of the car, still not running on all cylinders. So that doesn't seem to be the problem, the original modules are fine.

Note that this car was in a salt air environment part of its life and I have already changed the front alternator/ starter harness because the original one fell apart from oxidation. Its possible that my fuel injection wiring harness could be the problem.

soontobered84

Ali,
Do you know for sure which cylinders are not "firing"? It seems strange to me that it would not be an "all the time" thing. You said you were absolutely sure that no spark plug wires had been swapped (cylinders 5 & 6 for example which btw are my favorites to swap). I think either you or Mike told me that you checked for spark at the offending cylinders and there was good spark at both. That would lead me to suspect that the injectors for those 2 cylinders are partially clogged. This could account for the fact that it runs smooth at lower RPMs (it getting enough fuel from those injectors at lower RPMs) but doesn't run well at higher RPMs (those cylinders are not getting enough fuel due to the partial clogging of those particular injectors)
Compression/Fuel/Spark at the appropriate time is all it takes.

mdkelly1

What John and Malcom are saying about the injectors/fuel delivery makes sense with the symptoms you've described.

namasgt

You guys do have a point and I have plans to take the injectors out. What we were doing on Saturday was unplug the spark plug wires to see if disabling any individual cylinder would affect the ruff idle. Number 4 did not make a difference when we unplugged it. So we took the wire for number four plugged in a spark plug and it was sparking fine. Then we went and tried to listen to the injectors didn't have a stethoscope, (planning to go buy one right now) so I used a long screw driver to listen to each injector. #4 felt to be clicking weakly compared to 1,2, and 3 not as strong of a tapping sound.

But I did have similar issues to this GTS when the car was drivable. Every time I was on the HWY, felt like it hit the rev limiter, like all cylinders got cut out for a split second. Mine felt more violent when it happened compared to the videos on this thread, which I think are due to having an automatic.

https://rennlist.com/forums/928-foru...esitation.html

the flyin' scotsman

I too couldnt believe how badly the car I worked on ran after a full intake refresh including the Ford FIs but can assure you thats all we changed to bring the car to perfect.

namasgt

I found the problem,

Just right now I was going over everything again. Then from learning from here I decided to wiggle the wiring harness going to the injectors that I felt were not running right. The first one I tried was #6 and all of the sudden the car ran a little better then it shook and stopped running. I look down and the wiring harness was completely broken off from the boot. Will the car shut down if the two wires touch each other or damage the LH?