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(Post Link) post #1 of 15 Old 13-10-11 Thread Starter
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Jts slight misfire

Hi all,
I know theres alot of posts on this subject and i believe i've read most of them with out a complete answer to my problem, my 2003 156 jts has slight misfire when idling. I had this problem before which was lambda sensor so i replaced and cleared the fault code all was good.
This time theres no fault codes, tried disconnecting coil packs in turn to see if it was one of them. Checked and cleaned every connection with electrical cleaner, thing is its just had new spark plugs (correct ones) and seems to be a little worse. Its fine most the way through rev range and pulls hard, just at low revs and idling.
Could my other pre cat lambda be on its way out, just not servere enough to throw up fault code? really dont know.Iits a lovely car and i've wanted one for ages so wish to sort this out.
Any suggestions much appreciated. Jed
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Plug in and have a look at the real time lambda sensor values, to see if they are switching as quickly as they should or if the one you haven't replaced has gone a bit slow.
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(Post Link) post #3 of 15 Old 13-10-11 Thread Starter
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Ok thanks,
Gonna have another fiddle with it sat morning to see if i can get to the bottom of it. Am i right in saying if it was Maf it would run crap right through rev range? cheers Jed
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Ok thanks,
Gonna have another fiddle with it sat morning to see if i can get to the bottom of it. Am i right in saying if it was Maf it would run crap right through rev range? cheers Jed
Yes, usually it would affect the whole of the rev range.

One other thing I've just thought for you to check is the flexi section of air ducting just before the throttlebody, these can leak and cause unsteady idle & misfiring.

I hate to say it, but it could also be the start of injector problems. 70-80k is usually when they start causing trouble.
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(Post Link) post #5 of 15 Old 13-10-11 Thread Starter
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Oh great, mines now on 70k. Thats pretty expensive repair isn't it?
I've just replaced that section of ducting as old one split. What will happen if injectors get worse? (symptoms). I do have a hole in second silencer and blowing from flexi section of exhaust that wouldnt affect idle would it?
Sorry for many questions just alittle worried now. cheers Jed
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I'm sure the exhaust won't be causing you any problems by this time next week

See how you go on with the lambda sensors. Injectors are roughly sixty quid each for reconditioned ones, but its a few hours labour to change them as you have to remove the inlet manifold, and they are very tricky to fit and ensure they are properly sealed.
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(Post Link) post #7 of 15 Old 13-10-11 Thread Starter
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Ah yes i believe we spoke earlier on the phone regarding exhaust, nice doing business with you. Ok i'll keep my fingers crossed for a simple fix, not normally my luck though. Don't really want to go down injector route. Wish i could drop a diesel lump in it.
Anyway thanks for advice if you think of anything else please let me know.
Regards Jed
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OK, fingers crossed its just a lambda. If you're ever passing you're welcome to pop in, we can plug the car in and see if the lambdas are behaving themselves.
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147 1.8 evo

hi there guys, i have a 147 1.8 with the same problems...only when cold start is aplied.
it stutters and it seems to run on 3 cilinders if given no gas from time to time.
if the car is on right temperature there is no problem at all....and the whole car just acts normal and pulls very good
let me know what it issue was
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Quote:
Originally Posted by Jed25 View Post
Hi all,
I know theres alot of posts on this subject and i believe i've read most of them with out a complete answer to my problem, my 2003 156 jts has slight misfire when idling. I had this problem before which was lambda sensor so i replaced and cleared the fault code all was good.
This time theres no fault codes, tried disconnecting coil packs in turn to see if it was one of them. Checked and cleaned every connection with electrical cleaner, thing is its just had new spark plugs (correct ones) and seems to be a little worse. Its fine most the way through rev range and pulls hard, just at low revs and idling.
Could my other pre cat lambda be on its way out, just not servere enough to throw up fault code? really dont know.Iits a lovely car and i've wanted one for ages so wish to sort this out.
Any suggestions much appreciated. Jed
As much as we hate to say it Dan is probably 100% correct on the injectors. The JTS just knackers them. I see lots of people fiddling around with coilpacks, loom connectors,lambda etc but it is always the injectors.

Quote:
Originally Posted by thamaesta View Post
hi there guys, i have a 147 1.8 with the same problems...only when cold start is aplied.
it stutters and it seems to run on 3 cilinders if given no gas from time to time.
if the car is on right temperature there is no problem at all....and the whole car just acts normal and pulls very good
let me know what it issue was
It is probably either a knackered spark plug or the coilpack breaking down on yours. Different head on a 1.8 147. It's only a TS
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Sounds similar to the problems I was having, tried coils/plugs MAF, still same. Mine is in Autolusso South having the injectors refurbishes. Do a search for a member called tashbat, he had quite a few problems leading to a complete failure of two of his injectors.
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(Post Link) post #12 of 15 Old 15-10-11 Thread Starter
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Hi all, think I may have made things worse, had another good go cleaning all the connectors and even took maf out and gave it a good spray with high quality electrical cleaner now I've got more eratic idle and maf fault code (dam) but I do wonder if maf may have been in it's way out? Only way to see is buying another I presume? I'd love to take my car to auto lusso so they can sort it out, but it's 3 hours drive away. Lambdas seem ok number 2 pre cat alittle lagging (the one I haven't replaced) what sort of voltage should they read on idle? Sorry for essay and loads of questions but you guys are very helpful, thanks in advance Jed
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(Post Link) post #13 of 15 Old 01-11-11 Thread Starter
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Hello again,

Replaced Maf (thanks to Dan for this at short notice) seems to be running much better. But definitely something up with Lambdas, not consistent.
Cars going in for mot tomorrow and for new exhaust (many holes). When it comes back gonna sort the lambdas and see what happens. I will get to the bottom of this ha ha. Many thanks for all your replies and help along the way. Jed
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Good to hear it is better. Lack of a lambda sensor fault code does not necessarily mean the lambdas are working correctly. Someone experienced in JTS engines can look at the live data for the lambda sensors and have a good idea as to whether they are working or not. Its worth having a look in the engine bay to see how the primary lambda sensors are attached to the car's wiring loom, whether they are plugged in as they should be or if the plugs have been cut off and they've been hardwired.
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(Post Link) post #15 of 15 Old 02-11-11 Thread Starter
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Hi again.

I would love to take it to a decent garage and give the car the attention it deserves but theres none near me (that i know of, any suggestions welcome), and i dont get alot of free time to take it any where far away.
The lambdas retain the original connectors so are not hard wired. Would you guys be able to tell me anything about the lambdas if i posted a few results from fiatecuscan on here i.e when idling and driving etc. As always any suggestions welcome and appreciated. Jed

Last edited by Jed25; 02-11-11 at 21:52.
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