The injector coils can be checked at the harness connector...no need to physically remove them for checking.
You only need to remove them if you think one or some of them are leaking. I have done that and it's not that hard. Just get some new 0rings before you start. Are you following the procedure in the factory service manual for checking the base timing?
Those individual connectors all feed into one (or two, depending on the year) main harness connector at the back of the fuel rail. The earlier models had one connector for each bank - later models had one connector for the entire rail, near the distributor. If you can figure out which wires go to which injector (colors), you can test them at the pins in the large connector.
lol damn, I feel kinda stupid now. Of course one could test the injectors at the other end of the connector^^ Thanks for the hint! :-)
About the base timings: I dont think i have the skill to do that, I also lack the tools Ignition Timings were set just a few weeks before i got the car (i guess in order to fix the problem) according to an invoice that came with the car. Ill try to check the injectors today (using an ohm-meter) and then move on to the next test
So I probed the injectors with the Ohm-meter at the connection Harness. It seems that Injector 1,4,6 and 7 share a common black wire (K), the others share a red wire (J).
Injector #1 - Connector A/K - 17.4 Ω
Injector #2 - Connector B/J - 17.2 Ω
Injector #3 - Connector C/J - 17.4 Ω
Injector #4 - Connector D/K - 17.2 Ω
Injector #5 - Connector E/J - 17.1 Ω
Injector #6 - Connector F/K - 16.8 Ω
Injector #7 - Connector G/K - 17.0 Ω
Injector #8 - Connector H/J - 16.9 Ω
So they seem to be ok?! Now I am really lost, the injectors were the last thing I had on my list to check
Injector coils look fine. That's not to say that they are correctly functioning mechanically, but you don't display any other symptoms supporting that.
A stuck open injector will usually give you lots of starting trouble, similar to a fuel pressure regulator with a blown diaphragm. The extra fuel creates a flooded condition.
A stuck closed injector will give you a dead miss on the offending cylinder and no more.
Based on the current evidence, I would say the injectors are just fine.
I have no starting problems at all.
I've changed out the oxygen sensor and the EGR solenoid today as a last attemt to fix the problem. Nothing changed.
The only thing different since i've gotten a new egr valve into place is that I do no longer get the error code E48.
Lots, but that's just based on the symptoms posted. Diagnosis needs to continue.
Still could use some more PCM data.
I always figured large backfires are ignition related; just like turning off the key for a second on a carbed car and turning it back on; BOOM (followed by lots of laughs). Either the dist is losing power momentarily or there is a strange uncommon issue inside the dist. I would verify that the car is charging properly. Then verify that there is constant voltage going to the dist. That would require wiring in a temporary voltage gauge and mounting/taping it on the dash pad. If voltage is constant and car still acts up then it must be inside the dist.
I made a startling discovery today.
As guys know I had a totally wrecked catalytic converter when I got the car plus error code E48 ("EGR System Problem"). I took care of the converter by replacing it with a fancy pipe^^ and fixed the E48 error by replacing the EGR Valve. Still, the stuttering and misfires remained.
Today, as part of a last effort, I tried to run the Chart A-7 Emissions Performance Test. This tests checks the charcoal canister purge line and switch. I found a red wire that was torn off at the connector to the canisters solenoid switch. This red cable seems not to be from the cars original wiring.
And all of a sudden I recalled that it was I that tore the cable in the first place when I was unplugging the air suspesion compressor harness (as my rear struts' air pockets are no longer airtight and I wanted to releave the compressor of its duty).
I've also noticed fuel fumes inside the car and a SWOOOOSHH noise when opening the fuel door. So air was being sucked into the tank. This red wire, obviously installed by the previous owner, powered the charcoal solenoid switch. Without the power-line the evaporative emission control system was not working. I read up on the matter and it seems like this could also cause the stuttering and misfire with my engine. Slight under-inflation of the fuel tank makes it hard for the fuel pump to provide the fuel needed, therefor causing the misfires. Of course you would not be able to detect that with a injector test while the car is in idle...
Anyhow - long story short: I've reconnected the red wire and drove 10 miles on the nearest highway. no problems with misfires. when i reached my local mcdonalds it startet to get strage: I was able to remove the ignition key completely and exit the car - while the engine was still running. I was unable to turn off the car. The only quick fix was to remove the red wire powering the EECS purge solenoid again. The car then shut down immediately.
When I got the car I was able to shut it down properly with this red wire connected to the purge solenoid. I tore the cable off weeks later. Today, codes E16 ("Generator Voltage out of range") and E47 ("BCM-PCM Data Problem") were set but not present while I was unable to turn off the car.
Also i've found the unplugged connector shown in the pictures. Any idea where it belongs?
What the heck is happening?!
That connector you have in the last picture, what color is the wire and is it a single wire in that connector? I looked for pictures, but don't see any and need to get to bed so I can get up in the morning. I will look tomorrow.
You have a mess going on there. Only the pink w/black and green w/white wires go to the purge solenoid/cannister. The only thing I can think where that single brown wire might go is the marker light on the fender or the cornering lamp. Any other secrets you not telling about yet?
Hmm the cornering lamp theory might be correct - as far as I know those weren't allowed back then in germany. Perhaps they simply disconnected it.
It's not my mess I'll have to do some measurements today. I guess they've installed the additional red wire because the pink/black one was broken and unable to supply the power needed. As far as I can make sense of the service manual the green/yellow wire is being grounded by the pcm while the pink/black one should permanentely be hot. If that's not the case it would make sense to get 12V from elsewhere. I just cannot make any sense of the car not shutting down then...
I've did a vacuum test for the purge line today,had a leaking line to the charcoal canister. replaced it. unfortunately the white smoke from the muffler got much worse. did some sort of oxygen test at the radiator cap. turend from blue to green instantly. head gasket. ARGH