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jts intermittent misfire

9K views 44 replies 11 participants last post by  BMP 
#1 ·
Our 2.0JTS is misfiring when under load, i.e hills or acceleration. When this happens the computer screen goes dim briefly & the engine warning light flashes. Yesterday I tried the 90 sec throttle reset & it ran perfectly afterwards revving cleanly thru the gears, today misfires again:mad:

My local garage have changed the plugs, cleaned the throttle body & run a diagnostic check to no avail, except a large bill.

Another mechanic I know has suggested a bad earth somewhere or HT leads breaking down.

Any ideas??
 
#3 ·
RichJTS is going thro similar issues, so far we have:

last week:
* HT packs x 4
* reset learned parameters

3 weeks ago:
* in-line fuel filter.
* corrugated/ribbed pipe from airbox to throttle body.

2 months:
* pre-cat lambda

3 months:
* replaced battery
* clean connector blcoks [ x 2 ] on bulk head

In all fairness the car does drive well UNTIL *some-thing* happens & then all hell breaks loose,

>> reporting Lambda errors [ which have been replaced ]
>> defective throttle tracks [ which have been cleaned & 'learned parameters reset' ]

imho that *some-thing* is connection related which we are going to address on Saturday ...watch this space.
 
#4 ·
also i believe that unless you use Bosch, iirc, spark plugs the HT system will object ... maybe its NGK .... my brain is turning to mush:eek:
 
G
#5 ·
Jez get it on the examiner as some of the other systems in the car might give you a clue and it is ngk plugs as bosch plugs only work properly on motronic 1.7 and 2.7..... but were the modifications carried out when the lambdas were changed
 
#25 · (Edited)
Hi Tainan,

Sorry for my bad english, i am from holland i own an very nice 156 JTS TI:rolleyes:


I also have a problem with my 156 JTS with returning misfires on cil3.

At the workshop is done so far,... complete head dismantle/ cleaning,... four new injectors one new coilpack on cilinder three,.... and new spark plugs, also compression tested and it was oke, and a part of the wiring was replaced.

one new lambda probe, and the first cat is replaced for a new one, it is all done under warranty.:thumbs:


But can someone tell me the location of the injection computer (on top of the n/s wing) ??
(picture maybe?)

Many thanks in advance :thumbs:
 
#12 ·
mine misfiring too...

Hi All,

I have exactly the same problem on my 2.0 JTS, it started a few weeks back, with a very occasional misfire under load, now it's happening a lot and this morning for the first time I had the warning message.

I want to fix myself if possible, but don;t have a diag cable, is there anything you suggest, or is it worth me taking to a garage to read diags or getting my own? Any instructions on making a cable anywhere?

Many thanks
J
 
#14 ·
misfire on 1...

Dave, cheers for this. I borrowed a cable from a colleague and downloaded the FiatECUScan software. Connected to car this morning and got the following: Misfires detected - Cylinder 1 misfire.

This weekend, I'll remove and clean and maybe swap with another to see if problem moves. Could anyone tell me how they are numbered, is it left to right for example? Fairly new to all this, but really want to learn to do stuff myself.

Also seem in other forums that the MAF can be at fault - anyone can tell me how to disconnect this temporarily?

Cheers
 
#15 ·
Dave, cheers for this. I borrowed a cable from a colleague and downloaded the FiatECUScan software. Connected to car this morning and got the following: Misfires detected - Cylinder 1 misfire.

This weekend, I'll remove and clean and maybe swap with another to see if problem moves. Could anyone tell me how they are numbered, is it left to right for example? Fairly new to all this, but really want to learn to do stuff myself.

Also seem in other forums that the MAF can be at fault - anyone can tell me how to disconnect this temporarily?

Cheers
no1 is at cam belt end and goes to 4 gearbox , youll probably find oil in plug well ,so clean it out and refit ,will probably fix your miss-fire:thumbs:
edit:::leave maf alone till misfire is sorted
 
#20 ·
OK, they weren't much help again saying it took them both... I went for a 14, but it looks way too big. I did notice someone must have topped the oil up messily at some point as there was quite a bit around the coil pack (only outside before you remove the pack). I visually checked the coil pack and it looked ok, cleaned up the oil off the top and then swapped coil packs 1 and 2. Still a bit jumpy, so will wait for the next warning now and then check which cylinder, hoping for 2, can then get a new coil pack. If 1, will go for new plugs and check the wiring. Thanks again for your help Dave.
 
#26 · (Edited)
A guy of squadra tuning was today at the alfa workshop, he told the most jtses have a bit problems wit little hikups at 900rpm reduce the sparkplug gap a bit wil help with that.

My problem of misfires could be an oil leak (problem occurs only with a cold engine, the will look at it.
 
#30 ·
Oke thanks Dave for your answer :D

So the lean burn and condensation can be a problem, when squadria remaps and disable the lean burn, she runs much smoother, also more horsepower and Torque at the middle revs.

To give it a treatment with the dieelectrical grease, wat are the best spots to apply it?

Thanks in advance Dave :thumbs:
 
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