Intermittent Misfire Problem
#46
Three Wheelin'
In the intermittent break down boat, here is my experience ,
Had this for almost a couple of years...spend almost 2k checking every electric components in the car including getting rid of a alarm...
Well in my case it was 3 broken screws of 2 9 pin sockets that had fall inside the ECU ( aftermarket one) they were rolling around inside the ECU creating all sort of problems ....
Worth checking inside your ECU as well
Good luck !
Had this for almost a couple of years...spend almost 2k checking every electric components in the car including getting rid of a alarm...
Well in my case it was 3 broken screws of 2 9 pin sockets that had fall inside the ECU ( aftermarket one) they were rolling around inside the ECU creating all sort of problems ....
Worth checking inside your ECU as well
Good luck !
#47
Burning Brakes
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Join Date: Feb 2002
Location: London, England
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Vandit sorry this didn't cure your problem. Maybe try the o2 sensor? I can only say what worked for me, but it obviously could be very different for you...
Not sure at what point you admit defeat at take it to a garage. Nowadays for me it's after about 5 mins...
Not sure at what point you admit defeat at take it to a garage. Nowadays for me it's after about 5 mins...
#50
Nordschleife Master
I haven't messed w/ the AFM. I've felt back there and it seems like my car has had the TSB performed, wiring on the plug is ziptied to the side.
I drove the car last Sunday morning, put some Seafoam in the tank and topped it off w/ fuel and drove around, and the hesitation was pretty mild, kicking in infrequently.
I tried to drive the car today (Saturday afternoon, 1 week later) and I didn't even make it out of the neighborhood before I turned back around for home. Very present hesitation.
I guess it looks like i'll be pulling it off the road and tearing into it again. I think i'm gonna pull the whole intake assembly off, give everything a looksee, probably do the wires while i'm there, etc.
I drove the car last Sunday morning, put some Seafoam in the tank and topped it off w/ fuel and drove around, and the hesitation was pretty mild, kicking in infrequently.
I tried to drive the car today (Saturday afternoon, 1 week later) and I didn't even make it out of the neighborhood before I turned back around for home. Very present hesitation.
I guess it looks like i'll be pulling it off the road and tearing into it again. I think i'm gonna pull the whole intake assembly off, give everything a looksee, probably do the wires while i'm there, etc.
#51
Rennlist Member
same problem - hesitation on light load, stalling when hot
I've been whittling this problem down also. Changed both caps and rotors. dealer changed pulse sender and the socket as well as CHT and socket. Used two quarts of techron and a 200 mile trip to autocross. Damn thing kept dying at the start line. The more I dig into this 23 year old engine, the more worn out Bosch plastic parts I find crumbling, so that may be a problem hiding in somewhere. A PO removed the cat and O2 sensor, and I think put the Euro plug in the DME. My mechanic says that adding back the cat and O2 sensor will not make it more responsive as the old style O2 sensors are slow to respond. But I can't believe that with as many people as have this problem and no definitive answer has yet appeared.
#52
just reading this thread and feel your frustration.
vandit, have you figured out the issues yet?
bert, same question?
i have had similar issues:
replaced:
idle air control valve
crank position sensor (reference sensor) check for proper 1mm gap
rebuilt - afm
considering rebuilding the ecu / dme
haven't checked o2 sensor
checked grounds on battery, alternator and starter
vandit, have you figured out the issues yet?
bert, same question?
i have had similar issues:
replaced:
idle air control valve
crank position sensor (reference sensor) check for proper 1mm gap
rebuilt - afm
considering rebuilding the ecu / dme
haven't checked o2 sensor
checked grounds on battery, alternator and starter
#53
Three Wheelin'
I haven't messed w/ the AFM. I've felt back there and it seems like my car has had the TSB performed, wiring on the plug is ziptied to the side.
I drove the car last Sunday morning, put some Seafoam in the tank and topped it off w/ fuel and drove around, and the hesitation was pretty mild, kicking in infrequently.
I tried to drive the car today (Saturday afternoon, 1 week later) and I didn't even make it out of the neighborhood before I turned back around for home. Very present hesitation.
I guess it looks like i'll be pulling it off the road and tearing into it again. I think i'm gonna pull the whole intake assembly off, give everything a looksee, probably do the wires while i'm there, etc.
I drove the car last Sunday morning, put some Seafoam in the tank and topped it off w/ fuel and drove around, and the hesitation was pretty mild, kicking in infrequently.
I tried to drive the car today (Saturday afternoon, 1 week later) and I didn't even make it out of the neighborhood before I turned back around for home. Very present hesitation.
I guess it looks like i'll be pulling it off the road and tearing into it again. I think i'm gonna pull the whole intake assembly off, give everything a looksee, probably do the wires while i'm there, etc.
#54
Nordschleife Master
Nope, haven't looked at the fuel pump and the car's whole intake and shroud area have been in pieces since my last response in this thread.
I found some interesting stuff like cracked intake manifold stacks and the gaskets at the base that were obviously failing. And while I've been in there, it's getting an O2 sensor and new plugs/wires, so we'll see what it runs like when I hopefully get it back together in the coming weeks.
I found some interesting stuff like cracked intake manifold stacks and the gaskets at the base that were obviously failing. And while I've been in there, it's getting an O2 sensor and new plugs/wires, so we'll see what it runs like when I hopefully get it back together in the coming weeks.
#55
Arriving at this thread late in the day but I've just cured an intermittent misfire with mine over the weekend. It never actually stalled but did hesitate badly. After reading the cars history file I noticed that these symptoms were previously diagnosed as the engine earth strap being corroded. This can only be accessed from below the car so in the engine bay I ran a new, temporary earth cable between the right-hand engine mount and air-con compressor. This immediately sorted the problem, which now leaves me with the job of getting under the car to clean up the original.
Good luck.
Good luck.
#56
Rennlist Member
I still haven't solved all of the problem. Doesn't stall or overheat anymore. I tried cleaning the AFM and moving the wiper to a cleaner track, but that didn't help. My plug wire to AFM is very short and doesn't have anything to zip tie. I did zip tie the extra wire in my O2 sensor, and I think that helped. Also developed a very bad oil leak after some recent work. So I will be pulling everything off the top of the motor, checking for vacuum and oil leaks as well as getting the injectors done. will also change the ignition modules.
#57
Rennlist Member
Not entirely off-post, I am working with the software developed by another Rennlister to plot several engine parameters live and in color. As presented the only thing you can do is a screen capture ore a data log. I am trying to import the data log into Excell so I can analyze it more thoroughly, but because there is a lot of text and because my old brain has forgotten a lot about Excell, I have not progressed very far. If anyone has any suggestions of an easy way to import this data and then turn it into a live graph, it would be a major tool to spot this type of problem.
#58
Is the data being written to a text/log file in realtime? You can perform in import into Excel but this wouldn't update without intervention. You could employ the ODBC/OLEDB driver to use the log file as a 'text type' database, constantly polling the data source and re-drawing a graph. I'll help if I can.
#59
Rennlist Member
Sorry, that post was not up to my usual quality. The software mentioned is OBDPlot and it works through the adapter Tore B sells for the conversion of the round plug to a serial line to the USB on a Windows computer. It does a real time plt on the screen in color that is very useful. It also does a data dump to a text file named OBDPlot.txt. You have to catch this file and rename it before you run the plotter again, because it saves to that name always. I remember reading something about omitting the debug information to clean up the tex file. Will try that when it warms up a bit.