Technical Croma stutters at around 200rpm
- Thread starter Dazler22
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Technical Croma stutters at around 200rpm
Could be EGR valve related.
The EGR valve opens at 2000rpm and cloases at 3000rpm
Also peak torqe starts at around 2000 rpm.
I think also (only think as I have no authoritive information) that when the engine is on a maximum / power request EGR is not operative. Most modern ECUs drop/disable stuff/demands when maximum power is required. One example of this which I do have good information on is the airconditioning compressor.
The EGR valve opens at 2000rpm and cloases at 3000rpm
Also peak torqe starts at around 2000 rpm.
I think also (only think as I have no authoritive information) that when the engine is on a maximum / power request EGR is not operative. Most modern ECUs drop/disable stuff/demands when maximum power is required. One example of this which I do have good information on is the airconditioning compressor.
Stutter update,
Took the car back to the fiat dealer for them to fit anotherEGR vale last Tuesday,
All was fine for the first 10 miles then the stutter atabout 2000rpm came back.
Took the car back & they have now fitted a modified gasketon the EGR vale,
It is now improved the running of the car but the stutter isstill there but not as violent.
I can’t keep paying out for something that’s not gettingresolved & garage says not much more they can do.
Never had this problem with my first Croma but looks like I willhave to live with it.
tarquin1867
Member
Might be a complete red herring but I had just the same problem with my Marea diesel. It turned out to be the MAF sensor after the air filter. The whistling noise went after I changed the MAF and I assumed that the turbo was releasing pressure as the ECU was being told that we can`t put that much fuel out as we dont have enough air!
The MAF has been such a problem with Fiat they have now made it an exchange part which allows them to charge more for them as we as mere owners think we are getting a good deal. Bloody frustrating!!
The MAF has been such a problem with Fiat they have now made it an exchange part which allows them to charge more for them as we as mere owners think we are getting a good deal. Bloody frustrating!!
Simplest to quickly eliminate the egr by blanking it off altogether and see if that cures it. It will throw on a check engine warning light but you can download the software and reset it yourself with a cable of ebay.
Having said that the odds of 2 egrs failing and the mod gasket (depening on the gasket) not fixing it are slim and I think there's a good chance that it's the maf.
Can anyone confirm that the test for a dodgy maf is just to remove it and see if that helps? I'm sure it was one of the tests I did when + was diagnosing my own egr's failure.
Having said that the odds of 2 egrs failing and the mod gasket (depening on the gasket) not fixing it are slim and I think there's a good chance that it's the maf.
Can anyone confirm that the test for a dodgy maf is just to remove it and see if that helps? I'm sure it was one of the tests I did when + was diagnosing my own egr's failure.
Yes, if you disconnect the MAF you will get an engine light but the 1800-2000 RPM stutter will go. When you reconnect, the light (and smooth running) will last for three driving cycles.
HTH
CJ
HTH
CJ
Disconnecting the maf's got to be the way to go then.
Dazzler22 - do you know how to do this? It's a 5 minute job if you're comfortable with a screwdriver? Also, don't panic if the check engine light doesn't go away straight after you put it back in. What we mean by 3 cycles is to warm the engine up fully by taking it on a decent drive and then letting it cool down fully.l 3 times.
Dazzler22 - do you know how to do this? It's a 5 minute job if you're comfortable with a screwdriver? Also, don't panic if the check engine light doesn't go away straight after you put it back in. What we mean by 3 cycles is to warm the engine up fully by taking it on a decent drive and then letting it cool down fully.l 3 times.
You don't need to cool down the engine and then warm it up again, just warm it up one time and then stop and start it two more times and the error goes away. Tested.
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Thanks everybody I will try disconnecting the MAF tomorrowand come back with an update.
Fingers X
P.S I was told by the Fiat garage that it takes 20mins for the ECU to power down then the engine light will be off next time i restart after the 20min period after reconecting the MAF.
Another stutter update,
I disconected the MAF today and took the car for a run, well what a difference it runs like new no stutter and very smooth.
The funny thing is that no check engine light came on.Why?.
So my dad has a croma and im going to fit his MAF just ta make sure before i buy one. The conclusion we are comming too is i had a faulty MAF made worse with a clogged EGR.
Anybody know the cheapest place for a MAF.
Dazler22
I disconected the MAF today and took the car for a run, well what a difference it runs like new no stutter and very smooth.
The funny thing is that no check engine light came on.Why?.
So my dad has a croma and im going to fit his MAF just ta make sure before i buy one. The conclusion we are comming too is i had a faulty MAF made worse with a clogged EGR.
Anybody know the cheapest place for a MAF.
Dazler22
tarquin1867
Member
Just had a quick squint on E_Bay. When I got back to the keyboard , having fainted, I had to slap myself across the face in case I was dreaming!!!
They want £165 for one ------ When I bought one off E_Bay it was £90 against a quoted Dealer price of £130inc VAT. exchange.
Good luck with your search, could try a Vauxhall Vectra to compare prices.
I`m also amazed that you didn`t get the MIL light up.
Also, just a thought , i wonder if the plug onto the MAF may be faulty. Its in an area where it can be abused as work is done to get at the back of the engine etc. If it is shorting somewhere inside it it may be fooling the ECU into thinking everything is hunky dory!
I'm surprised too that the check engine light didn't come on - mine did but there were other problems too. Do you have access to ecuscan that you can use to check whether the ecu knows that the maf is missing?
Anybody know whether it's possible to remap it out or bypass the wiring?
Have you had the car a while?
Unlike the Egr or Dpf the ecu actually needs the info that the maf gives it. Otherwise the fuelling will be wrong and can lead to all sorts of problems. If it knows it's missing it will just assume a safe set of parameters to protect the engine.
Hi Everyone, Another Stutter Update.
Took the MAF of my dad’s Croma and fitted it to mine, wethen went for a drive for a few miles stop and starting the car, The enginelight went off and car drove like a dream (no stutter).
Result! it’s the MAF,put my MAF back on my car and to my surprise the car has driven ok with nostutter for 3 days now so I’m very puzzled and fed up the I’m starting tostutter.
So I’m going to leave well alone for now unless it startsagain.
Thanks’ everyone for help & advice.
Sometimes a simple bad connection can account for many issues.
Any electrical connector in a car, especially the engine, underside, wheel areas, etc. are subject to anything but a comfy warm and dry environment.
Often a simple connector disconnect, clean and lube will solve many issues.
Any electrical connector in a car, especially the engine, underside, wheel areas, etc. are subject to anything but a comfy warm and dry environment.
Often a simple connector disconnect, clean and lube will solve many issues.
tarquin1867
Member
If you look at the connector on the MAF you will see it has a small yellow clip integral to it . If this is not engaged properly the connector could come apart in use, unlikely but possible.it works like a spring clip.
Hi everyone,
Just to let you know I’m still getting the stutter at 2000RPM & just having to live with it as the dealer has admitted defeat & say it’s not worth looking into anymore.
I can’t believe that a modern garage with all there kit can’t find what is wrong, & they would not fit a 3rd EGR as they were adamant that it’s not the cause.
Even the flying doctor from fiat had a look & said it could be a 10001 things.
Well I just feel bloody great.
Dazler.
Just to let you know I’m still getting the stutter at 2000RPM & just having to live with it as the dealer has admitted defeat & say it’s not worth looking into anymore.
I can’t believe that a modern garage with all there kit can’t find what is wrong, & they would not fit a 3rd EGR as they were adamant that it’s not the cause.
Even the flying doctor from fiat had a look & said it could be a 10001 things.
Well I just feel bloody great.
Dazler.
tarquin1867
Member
Sorry Daz- but the thought of a "flying Doctor" from Fiat makes me want to start watching Skippy the bush kangaroo all over again.
BWAAAAAAAAAAAAH
BWAAAAAAAAAAAAH
