Gremlin

[Maddog]

Bimmerheads,

I need your help to find the gremlin in my 1988 325is. The engine intermittently cuts out. Recently the check engine light would flicker, engine stumble slightly, but did not stall. The last time it stalled, it was under load at highway speed. Didn't notice check engine light since I was more focused on getting the car to the shoulder. Car started up afterwards. I have replaced the following and still experience the same:

- Fuel filter
- CPS
- Relays: Fuel pump and engine management
- Fuel purge valve
- TPS
- O2 Sensor
- Cap and rotor

Fuel pump was replaced 50K miles ago.

I am inclined to replace the ignition switch and plug wires. Only other item is the fuel pump.

I appreciate any insight.

Thanks.

[MrBurgundy]

I actually had a similar problem that I fixed today.

I pulled my injectors out and cleaned them, problem went away.


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[5Toes]

the engine cuts out? does the tach drop when that happens? sounds to me like the DME is getting intermittent power. possible causes could be a bad main relay, a fusible link failure, ignition switch or other

Id try the ignition switch last. get a new main relay and check the wiring for frays or rough spots. the fusible link you can track down and replace with an inline fuse. my e34 had a similar problem where it would only start if it felt like it

[Kershaw]

Replace the main relay.

[TobyB]

Gremlin

We had a '76 Pacer. Probably worse than a Gremlin...

t

[CamE30]

May try a replacement DME and or investigate the C191 connector for any presence of coolant or corrosion.

[jlevie]

If the tach drives towards zero during an event the CPS, engine harness, fusible link, or DME all all suspects. I see that you replaced the CPS. Was it an OE/OEM part? Did you adjust the CPS bracket for 2mm of clearance between the CPS and the timing wheel?

[Maddog]

Thanks all. And yes, the tach zeroes out during the event. I have two DME and problem occurs on both; one DME with Mark D chip and the other stock. I had RyanGMW replace CPS (OEM) when he did my head gasket so know it's correctly installed.

Event happened again today while driving in city streets; same situation with check engine flicker while engine suddenly dies and tach zeroes; notice a slight intermittent rough idle now. Car starts right up after the event.

I will check the following and and keep you posted, including inspecting the injector and connections; installed reconditioned injectors when I did the engine build 50k miles ago.

[Maddog]

Fellow Bimmerheads,

First thanks to directing me to check the C191 connector. As I was finishing up using contact cleaner and wiping down the residue inside the male connector boot, two wires just separated from the connector from corrosion which is not visible. I am really fortunate to have this happen now and not on the highway. Most likely this has to been the gremlin hiding the past several year awaiting to cause breakdown that would have stranded me.

Most appreciate to you all for directing me to it.

Will provide update once I fix the wiring and if this is the culprit, those with this intermittent problem should redo the wiring since the corrosion is hidden from inspection.

[CamE30]

AWESOME! In a way you found the issue. Definitely keep us updated.

[Maddog]

Still waiting for the Weather Pack connectors to arrive. Once fixed, I will provide an update over a period of time to confirm the fix. Apparently, the frequency of stalls increased after I replaced the TPS, charcoal canister, fuel purge valve and vacuum hose several weeks ago; before it would be maybe only when it was real hot and every 3-4 months. All of this activity must have created a larger gap between the corroded wire and the connector which allowed the circuit to open more frequently. I was on borrowed time before not being able to start up the car.

I am hoping I can soon sleep without worrying about stalling on the highway.:yawn:

[Maddog]

Gremlin Update:

Corrosion at the male side of the C191 Connector was severe; three wires were corroded severely and most likely either severed or hanging on by strands. This may explain the early symptoms of cutouts in high temperature areas (100 degrees F).

The wires in the care are prepped and ready (I may need to cut off more based on the oxidation on some of the wires-see discoloration on photo); I under ordered the Weather Pack seals. Stupid me , I was only thinking 6 wires, not 6 sets of wires so only have half of the seals; I will need to wait until Tuesday to have my "is" up and running. I ordered my Weather Pack material from Del City in NV; very quick service and you do not have to buy in bulk. Also, being a tool snob, I purchased the 1-step crimper thru Amazon.

Next update will be with the connectors and hopefully car running. :D

[Maddog]

Finally completed replacing the C191 connector with a Weather Pack.:razz:

As others have mentioned, there are only six connected wires; the seventh is open.

Test drive it tomorrow and will provide an update in the future to confirm the exorcism of the gremlin. :devil:

[Maddog]

Well, the gremlin is still haunting my E30. Same symptoms, unexpected stall but engine is able to restart, stumbling with CEL flickering and bucking under load.

I will check the C101 connector and possibly replace the engine management relay (white relay).

[Maddog]

After doing more research, I will also replace the ignition switch since it's probably the last electrical/mechanical fuel/ignition part that is still an original part since the 1988.

Keep you posted.