Greetings fellow members of R3v, my name's Doug. This is my first post so I apologize if it's in the wrong area, although I'm pretty sure I got it right. I've had my E30 for a while now, been lurking around these forums quite a bit and I admit, I've been lazy and haven't posted a single thing about my car until now. I guess a positive about the problem I'm having is it finally gave me a reason to get involved 
A little background on the motor itself just to help, I'd rather give more info than necessary than too little. Current mods to the engine include:
Rebuilt head by a BMW specialist shop up in Vancouver; new OE rocker arms and valves
Schrick performance cam
Schrick valve springs
Larger injectors (forgot the size, if relevant I can get it tomorrow when it's light out)
Long tube headers and magnaflow exhaust
Dinan chip
Now on to the problem...
A week ago she was running great apart from a slight idle fluctuation regardless of engine temp. A few days ago I noticed a very, and I mean very slight bucking while I was accelerating. It was most noticable in first and second gear, and I did notice a bit of hesitation between 2-3k rpm. For the past couple weeks my CEL has been on for my O2 sensor. Convinced this was the problem, I went to NAPA and ordered a Bosch O2 sensor and replaced that yesterday. However, on the way to the auto parts store, I noticed my car sounded different, almost as if it was only running on 5 cylinders. Also it was a bit louder, and had a very shaky acceleration like a continuous vibration from the engine. The bucking is gone, and now it just lacks power and seems to be running extremely rich; you can hear the fuel igniting from hitting the headers by a loud crack-like pop out of the exhaust (not like the normal downshift burbles of a tuned car). Lastly, when idling if you pull the throttle to rev it, the motor stumbles and almost dies out for a quick second before it actually revs.
Thinking it was all related to a faulty O2 sensor sending the wrong AFR's to the ECU I went ahead and replaced it hoping it would fix the problem. The check engine light is now gone, but the problem still exists. I am not throwing any codes as of tonight, which makes me think whatever the issue is is not monitored by a sensor although I could easily be wrong with this theory. At first I thought a vacuum leak, however I am now leaning more towards an ignition problem. I pulled a spark plug from cylinder 1 and cylinder 5 after work today to see how they looked and they were completely covered in a thick coat of carbon. Good news is it was not oil fouling and they were equally just as bad.
I'm going to grab some new ones tomorrow and see how it runs. Also, there is no smell of gasoline under the hood while it is running.
Other things I have checked:
-Plugs on the injectors are tight and plugged in all the way
-HT leads are all the way on, checked plugs, coil, and distributor.
-All fuses that were even slightly relevant checked out okay
-CPS is good, I've read it wouldn't even start otherwise
Things I have yet to do (partly based on the answers I get here)
-Compression test
-New spark plugs
-Inspect distributor
-Check spark from each lead
-Check fuel pressure, although I'm fairly certain it has nothing to do with fuel delivery
-Clean ICV
-Clean MAF
-Test for any vacuum leaks
-24v swap...
I also was reading up tonight on the engine coolant temp sensor and it sounds like a possibility... would this match my symptoms?
Am I on the right track? I don't want to spend time chasing a ghost. I need to get her running right since she's my daily here for a few months.
Also, I can get a video tomorrow and post it so the issue can be heard first hand. And apologies for this unorganized mess of a post, I feel like I'm writing a paper for school and losing interest with every keystroke.
Thanks!
A little background on the motor itself just to help, I'd rather give more info than necessary than too little. Current mods to the engine include:
Rebuilt head by a BMW specialist shop up in Vancouver; new OE rocker arms and valves
Schrick performance cam
Schrick valve springs
Larger injectors (forgot the size, if relevant I can get it tomorrow when it's light out)
Long tube headers and magnaflow exhaust
Dinan chip
Now on to the problem...
A week ago she was running great apart from a slight idle fluctuation regardless of engine temp. A few days ago I noticed a very, and I mean very slight bucking while I was accelerating. It was most noticable in first and second gear, and I did notice a bit of hesitation between 2-3k rpm. For the past couple weeks my CEL has been on for my O2 sensor. Convinced this was the problem, I went to NAPA and ordered a Bosch O2 sensor and replaced that yesterday. However, on the way to the auto parts store, I noticed my car sounded different, almost as if it was only running on 5 cylinders. Also it was a bit louder, and had a very shaky acceleration like a continuous vibration from the engine. The bucking is gone, and now it just lacks power and seems to be running extremely rich; you can hear the fuel igniting from hitting the headers by a loud crack-like pop out of the exhaust (not like the normal downshift burbles of a tuned car
). Lastly, when idling if you pull the throttle to rev it, the motor stumbles and almost dies out for a quick second before it actually revs.Thinking it was all related to a faulty O2 sensor sending the wrong AFR's to the ECU I went ahead and replaced it hoping it would fix the problem. The check engine light is now gone, but the problem still exists. I am not throwing any codes as of tonight, which makes me think whatever the issue is is not monitored by a sensor although I could easily be wrong with this theory. At first I thought a vacuum leak, however I am now leaning more towards an ignition problem. I pulled a spark plug from cylinder 1 and cylinder 5 after work today to see how they looked and they were completely covered in a thick coat of carbon. Good news is it was not oil fouling and they were equally just as bad.
I'm going to grab some new ones tomorrow and see how it runs. Also, there is no smell of gasoline under the hood while it is running.Other things I have checked:
-Plugs on the injectors are tight and plugged in all the way
-HT leads are all the way on, checked plugs, coil, and distributor.
-All fuses that were even slightly relevant checked out okay
-CPS is good, I've read it wouldn't even start otherwise
Things I have yet to do (partly based on the answers I get here)
-Compression test
-New spark plugs
-Inspect distributor
-Check spark from each lead
-Check fuel pressure, although I'm fairly certain it has nothing to do with fuel delivery
-Clean ICV
-Clean MAF
-Test for any vacuum leaks
-24v swap...
I also was reading up tonight on the engine coolant temp sensor and it sounds like a possibility... would this match my symptoms?
Am I on the right track? I don't want to spend time chasing a ghost. I need to get her running right since she's my daily here for a few months.
Also, I can get a video tomorrow and post it so the issue can be heard first hand. And apologies for this unorganized mess of a post, I feel like I'm writing a paper for school and losing interest with every keystroke.
Thanks!
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