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Discussion Starter #1
Ok, this is another mystery misfire on a 2000 156 Twinspark Sportwagon that I would appreciate some help with.

There are some common elements to other people chassing down mystery misfiring on TS and JTS, but my reading of the threads suggests not all are the same problem..... so the symptons are:

Intermitant misfire - Runs fine (but a little sluggish) below 3 -4000 RPM.

Badly misfires on full throttle acceleration - like breaks down completely and wont rev at all. Back the throttle off and it will eventually clear its throat.

Wont rev past 4000 rpm most of the time unless you slowly let the revs rise through the 4 - 5 K RPM flatspot, then it will rev out fine.

So, the fault is obviously Rev/Throttle position related.

I have a diagnostic cable but I am unable to get it to work on my vehicle. The Alfadiag software demo gets pulled up in my virus software as a trojan and the FiatECU software wont connect to my car with a port issue of some sort.

Reading through these threads it seems that some peoples issues are sorted by changing coil packs but some arent as are some by ECU resets etc......

My suspicion is that the problem is injector related rather than electrical? Anyone know how to test this? or clean/replace? I have run loads of injector cleaner through it over the past 6 months and see only a marginal improvement.

Spark plugs are about 60000K old and belts were done about 45000K ago. I have had the problem for about 6 months but have been driving around it. Would be nice to have it finally sorted. Any help or info would be much appreciated. Cheers, Ged.
 

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Discussion Starter #3
Have you tried unplugging MAF ?
No. Well, I hadnt....... MAF being the Air Flow Meter with the 2 large clamped on cables? I just did a quick lift and look and now it will start but wont rev at all! Bounces between 1200 and 1500 RPM. Thats all. Glad I just ducked down to the shop for milk before I did that! The injector light is now on the dash as well?
 
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Yes that the one - do you mean you have disconnected it and now it wont rev at all ?

If you have disconnected it then your injection light will be on.

Re port issues have you checked in device manager what com port is showing with your cable plugged into computer and then set that port number in settings in FES ?
 

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Discussion Starter #5
Yes that the one - do you mean you have disconnected it and now it wont rev at all ?

If you have disconnected it then your injection light will be on.

Re port issues have you checked in device manager what com port is showing with your cable plugged into computer and then set that port number in settings in FES ?
Yes, I have disconnected it and then reconnected it and now it wont rev at all. Starts, but just bounces between 1200 and 1500 rpm if I give it any throttle and the injector light is on.

yeah, I checked which port number which I think I reset to Port 8 to match the FES. Still wouldnt talk to the ECU.
 
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Ok - disconnect MAF, does it rev if so try taking it for a drive - it probably wont idle but see if it drives better.

Its not a selespeed you have by any chance ?
 

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Discussion Starter #7
Ok - disconnect MAF, does it rev if so try taking it for a drive - it probably wont idle but see if it drives better.

Its not a selespeed you have by any chance ?
Ok, will try that. No, not a Selespeed. This is my 9th Alfa and experience tells me Alfa and Auto are mutually exclusive terms!
 

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Discussion Starter #8
Ok - disconnect MAF, does it rev if so try taking it for a drive - it probably wont idle but see if it drives better.

Its not a selespeed you have by any chance ?
Ok, I gotta be on the wrong connectors here..... Im disconnecting the 2 clamped cables ontop of the box on the air inlet tract. There a too many pins and conductors for this to be anything but the ECU? Where is the MAF connector?

Sorry to sound like a dunce, I'm just not Motronic 7? literate.
 

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Plugs and belts are how old? :eek:
 

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Err yeah, missed that :D
 

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Discussion Starter #14
Plugs and belts are how old? :eek:
Thanks Davffc. we will get me talking Motronic 7 yet!

Ok, have unplugged the correct connector and yeah, it will run but no differrent.

1of1. I think the service life of Titanium (?) tipped plugs is 100000km (were 125000K on my 3 33's) and belts are 65000K? Correct me if Im wrong.
 

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Discussion Starter #15
BTW, will resetting the ECU be in order? All I have done it disconnect the 2 plugs and refit them?
 
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Ok was worth a try ( maf ).
Defo need to get FES working and see any error codes.
The standard Plugs are 60k miles/5 Years so yeah 100k kms. Belts 36k mls/ 3 yrs whatever that is in kms.
I changed the com port number in Device manager then set FES to that number in settings
 

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Discussion Starter #17
Ok worth a try.
Defo need to get FES working and see any error codes.
The standard Plugs are 60k miles/5 Years so yeah 100k kms. Belts 36k mls/ 3 yrs whatever that is in kms.
I changed the com port number in Device manager then set FES to that number in settings
Thanks Davffc. I will try some more diddling with port settings and see where I get to.

How do I reset the ECU?

I had better get to work soon so I have dusted off my alternative transport for the day, my 1983 Ducati Pantah, but I am in the middle of moving house and the Ducati just aint gonna cut it!
 

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Discussion Starter #18
This Fiat ECU Scan software is really bugging me now.......

I have reset my port to 1, the FES recognises the VAGCOM module and tests its latency etc but it wont connect to the ECU and says "Connection Failed. Check Cable and Port Settings" - Sure.......

Anyone know how to make these things work?
 

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This Fiat ECU Scan software is really bugging me now.......

I have reset my port to 1, the FES recognises the VAGCOM module and tests its latency etc but it wont connect to the ECU and says "Connection Failed. Check Cable and Port Settings" - Sure.......

Anyone know how to make these things work?
Go and have a read of the FES forum will help you witth 99% of issues.

This sounds like classic induction leak of maf issue...
 

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Discussion Starter #20
Go and have a read of the FES forum will help you witth 99% of issues.

This sounds like classic induction leak of maf issue...
Thanks biffa. Not quite plug n play then....... What was I thinking. Will work through some of that and see how it goes.

Would an induction leak be rev specific?

BTW, the other issue I have since I have buggared my ECU! (honestly, I just pulled and reconnected the 2 plugs!) is that the engine fan is running continually? The engine starts ok, but wont rev beyond 1500RPM. Just bounces between 1200 and 1500? Will do an ECU reset overnight.

What would I have tripped by pulling the 2 ECU connectors?
 
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