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Car is Surging

RPB81

E500E Newbie
Hello all my name is Rob, in need of some assistance here. Found some of the other posts very helpful, good site! My car has recently started to idle rough, surge, and almost feels like its going to cut out. Last week I had it in the shop for this, an hour after it was dropped off I received a call stating my car took a dump. The ICM was shot and not functioning. I was suspect at first about the repair shop as I only started using them recently, they are telling me that my car is dead and the part is $3600. I did research unearthing the fact that the ICM does indeed fail, so I started the search for a donor. I was lucky to find a second hand module that worked, figured my issue was solved and it seemed better off at first until it all started again. From what I have been reading some users say its essential to replace the coil, cap, rotor...I am willing to do whatever is necessary! I am almost positive this is an ignition related issue. At the same time do not want to throw unnecessary parts at it. Taking it to a recommended 124 specialist soon but was interested to get some feedback here too. My car just rolled over 60k, always maintained! Feel nervous driving on this new module when it sounds like this problem is corrupting it and could potentially leave one stranded, need to get it fixed asap.
 

gerryvz

Site Honcho
Staff member
Doesn't seem right that an EZL (the part that I THINK you are calling an ICM here) would go bad after just 60K miles. Generally heat/mileage/use is what gets them over a long period of time.

Also, it doesn't sound to me like the EZL is your problem. Sounds to me more like the ETA (electronic throttle actuator) at first blush. What you need to do is to get the car to a specialist who can pull the codes and do a "live data" readout using a STAR Diagnostic System or appropriate HHT (hand-held tester). Any codes that are tripped would give you a very strong directional indicator as to what the problem really is.

If the caps and rotors haven't been replaced at 60K miles, they are very likely overdue for replacement. That is a normal maintenance item and these cars do go through them. Really seem to be a part that lasts in the 25-40K mileage range before they get gummed and carboned up. So I'd replace them as a matter of course, no matter if the car was running perfect or not.

As far as the EZL, generally you will get a situation with an EZL where the car will just not start/run, or it will run rough because the car is only running on one bank of cylinders. That's very different than the rough idle and surging that you are getting.

If and when you ever do replace an EZL, you should do two things: a) be sure to use heat-sink paste between the bottom of the EZL and the fender of the car where it mounts; and b) be sure to replace the coils at the same time, because a bad coil can and will cause an EZL to die. You want as pure as possible an electrical signal going between those coils and that EZL.

The heat-sink paste is very similar stuff to what they use with microprocessors to transfer processor heat to the attached heat-sink surrounding the processor. You can get this paste at the Radio Shack or at any Fry's Electronics store if you have them in your area.

Bottom line, get your car into a specialist who is equipped with the tools and techniques to properly diagnose the car. They should find the issue pretty quickly.

Cheers,
Gerry

P.S. :welcome: Please be sure to fill out your profile (location, car, etc.) so that we know a bit more about you.
 

RPB81

E500E Newbie
gerryvz said:
Doesn't seem right that an EZL (the part that I THINK you are calling an ICM here) would go bad after just 60K miles. Generally heat/mileage/use is what gets them over a long period of time.

Also, it doesn't sound to me like the EZL is your problem. Sounds to me more like the ETA (electronic throttle actuator) at first blush. What you need to do is to get the car to a specialist who can pull the codes and do a "live data" readout using a STAR Diagnostic System or appropriate HHT (hand-held tester). Any codes that are tripped would give you a very strong directional indicator as to what the problem really is.

If the caps and rotors haven't been replaced at 60K miles, they are very likely overdue for replacement. That is a normal maintenance item and these cars do go through them. Really seem to be a part that lasts in the 25-40K mileage range before they get gummed and carboned up. So I'd replace them as a matter of course, no matter if the car was running perfect or not.

As far as the EZL, generally you will get a situation with an EZL where the car will just not start/run, or it will run rough because the car is only running on one bank of cylinders. That's very different than the rough idle and surging that you are getting.

If and when you ever do replace an EZL, you should do two things: a) be sure to use heat-sink paste between the bottom of the EZL and the fender of the car where it mounts; and b) be sure to replace the coils at the same time, because a bad coil can and will cause an EZL to die. You want as pure as possible an electrical signal going between those coils and that EZL.

The heat-sink paste is very similar stuff to what they use with microprocessors to transfer processor heat to the attached heat-sink surrounding the processor. You can get this paste at the Radio Shack or at any Fry's Electronics store if you have them in your area.

Bottom line, get your car into a specialist who is equipped with the tools and techniques to properly diagnose the car. They should find the issue pretty quickly.

Cheers,
Gerry

P.S. :welcome: Please be sure to fill out your profile (location, car, etc.) so that we know a bit more about you.


Thanks Gerry, I have found your feedback very helpful! Looks like I have some parts to order since I know the cap and rotor are original.

My car did get a new throttle actuator at 55k, there was a code for this not too long ago though but figured it was stored from before. Work order stated that "car has ASR light on and would hardly move", new actuator installed at cost of $1300 + other parts. I will get this looked at, hope its not the issue again! Car did have recent 60k done at 55k, all the fluids were flushed in addition to new plugs. At this point I think it would be wise to replace the wires, rotors, cap, and coils w/ the new EZL in there as Gerry mentioned. Fingers crossed this will fix my problem. After doing so I will try out my old EZL to see if it fires up and find out whether or not this questionable repair shop was trying to pull a fast one on me w/ a $3600 part. Could have been bad coil or one that is nearing the end of its life.

In regard to the new rotor, I am being told that I need a new bracket, is this true? Its telling me the new one could potentially catch on fire w/ the old bracket. What else is recommended when switching out the cap, thought I read there was a $4-10 part that should also be changed, if so part# please? Seems like the best prices are @ Europartsdirect and AutoHauz follows.

My car is a 1993 that just rolled over 60k
 

RPB81

E500E Newbie
bing said:
you'll find what you need to know about caps/rotors/seals/brackets from the post below. more than likely if it's the original rotor you'll need a new bracket, but info from the post below will give you an idea..

don't get what you mean ''1993 w/60'''?

viewtopic.php?f=19&t=364&p=7144&hilit=bad+caps+and+rotors#p7144
Thanks, I found this post but there was no confirmation if it was used or not. Apparently the new rotor would have to be modified in order to fit the orig bracket, looks like new adapters too. Starting with new Bosch wires tomorrow and will go from there. Looks like I will do the coils asap since I have the new EZL in there, then cap and rotors... Is a coil the main culprit when it comes to frying the EZL? Thought bad wires could also raise resistance which in turn will also plague the unit. This issue of mine also seems like weather is a factor, we had an unusual hot day close to 87 degrees and it did not surge after a min of driving like usual. Today it was cooler and issue reappears, no check lights on since surging started.
 

RPB81

E500E Newbie
Wow! Should have checked my cap and rotors before posting! Yeah I would agree that they need replacement every 30-50k!!

Hopefully this will solve my issue, still questioning why my EZL went bad although I have read many of others going around 60k, will be buying a backup unit soon. Could be too much heat from the M119. My coils checked out fine but still might replace with new EZL.

Thx again guys, good forum here!
 

gsxr

.036 Hoonigan™, E500E Boffin
Staff member
RPB81, is the car running fine now? Wasn't sure from your last post(s)...

:cheers:
 

RPB81

E500E Newbie
gsxr said:
RPB81, is the car running fine now? Wasn't sure from your last post(s)...

:cheers:
The cap and rotor definitely need replacing due to carbon buildup, hopefully will do the trick!

Still looking into the EZL/ICM issue.

Thx!
 

gsxr

.036 Hoonigan™, E500E Boffin
Staff member
The EZL is generally not an intermittent failure - it usually either works or it doesn't. You can test your old unit by laying it on top of the current unit, the wires will just fit. Lay a rag over the existing unit to keep the goop off it while testing. If the car starts, runs, and drives ok with the old EZL, it's fine. BTW, did you get a spare of the exact same part number?

On a side note, verify the proper spark plugs are installed. It should have non-resistor plugs, Bosch F8DC4, available from AutohausAZ.com for ~$1.60 each. For some reason, the early M119 ignition systems are not happy with fancy platinum or yttrium plugs, multiple electrodes, etc. Many mechanics don't realize this and think they are doing you a favor by "upgrading" the plugs. Don't do it - keep F8DC4's in there.

:detective:
 
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