Serious CEL issue :(

Twinturbo

Junior Member
Messages
101
#1
After doing a lot of searching hoping to find this solution I still havnt had luck so to cut down on time I'm hoping someone can shed some idea and light on my issue

Previous car issues random CEL triggers on startup car revs up to high so I turn off then next start everything's fine put it down to usual 3200gt temperament
Next few drives CEL starts triggering mid drive but no driveability symptoms then will just turn off again as fast as it came on , I check everything before every drive oil pressure good, oil level good , battery full, All fluids fine.

Anyway after a long nights drive of it running brilliantly really loving this car boost comming on strong no CEL for days I'm so glad I bought it then it all comes crumbling down the throttle starts to be a bit jumpy slightest touch gives more throttle than it should then the CEL came on I pulled over and checked all I could in the dark on the side of the highway 1hour from home, reset battery, did the 2min ignition and 5 sec throttle reset which usually cures the problem to no avail

Current symptoms
CEL on ignition won't disappear with any reset procedure
ive checked the pedal pot signal 440-3200 from ignition to full throttle that normal?
That's joined yellow and white wires separating did nothing to help problem
I don't have any diag equipment can someone recommend the best for our cars or even anything that can help with error codes and possible erasing them?
I would really appreciate anyone's advice and am really
Hoping I can sort this myself before resorting to handing my car over to some stealership
Car has a upgraded contactless TB built by the Maserati shed but when I emailed him he said he did the best he could with what he had so that didn't sound like a very good guarantee of lasting workmanship yikes

Thanks in advance for anyone
Helping and giving the time to reply
Much appreciated
 

allandwf

Centenary Club
Messages
6,961
#2
You need to get the codes read, sounds like a Throttle body or pedal pot issue. If it's 2001 or later then any generic code reader will do the job. If not then not so easy, a trip to an indy may be needed. Unless you have the codes you will be clutching at straws and wasting time. When mine used to throw the odd CEL it was the Pedal Pot, never had an issue since it was upgraded to contactless. The Throttle body was changed later, just for peace of mind.
 
Messages
1,798
#4
Reading the codes i think is really quite important. It is not uncommon for the throttle body and the pedal sensor to have problems at the same time, and without reading the codes you cant really tell if its one problem repeatedly causing problems or several different problems. I think since you have said that the pedal sensor calibration has cleared the problem in the past it would suggest you at least have trouble with the pedal sensor. while joining the white and yellow wires is not the best idea long term it normally helps so the fact that does not help might indicate you have at least one other problem. The engine revving high at start up is not really a symptom of the pedal sensor problems it is usually a problem with either air leaks around the plenum or the magnets on the throttle body motors breaking up or just suffering dirt and corrosion. So i would try to get some way to read your error codes first off and start by looking just what is tripping the CEL, and whether its the same problem or several different ones. I know early on, on my car, i had problems with air leaks, pedal sensor and throttle body all at the same time and it was hard to sort out. and yes i can help with the pedal sensor if you need it.
 
Messages
1,798
#5
sorry on your question of ways to read the codes, it depends on the age of your car, early cars are not ODBII compliant and have an older 2 pin port and you need adapters to read the codes. There is a thread here some where. On newer cars that have an ODBII port any diagnostic reader will work, there is also a separate thread some where on both hardware and software for reading codes.
 

Twinturbo

Junior Member
Messages
101
#6
sorry on your question of ways to read the codes, it depends on the age of your car, early cars are not ODBII compliant and have an older 2 pin port and you need adapters to read the codes. There is a thread here some where. On newer cars that have an ODBII port any diagnostic reader will work, there is also a separate thread some where on both hardware and software for reading codes.
Thanks a lot for replies , unfortunately mine is the 2000 model needing adapter so I have some diagnostic equipment on the way, since it's undrivable and not a daily I will try and trouble shoot this at home as much as I can before having it towedand throwing away $$$$, are there any simple throttle body tests I can do to see if it's ******* without having to take it off and open it up? and considering it was fixed by Maseratished only 2 years ago contactless could it be so broken that it can only be fixed temporarily and require a whole new unit?
 
Messages
1,798
#7
I think one of the accepted basic tests on the throttle body is to remove the main intake hoses and push the butterfly with your finger, it should move smoothly and return to the closed position as far as i remember. It is common for this movement to be rough or indeed sticking and this is often the source of the problem.
 

Trev Latter

Centenary Club
Messages
1,094
#8
If your TB is already contactless, it may be one of the "other" issues that can occur. It could be a circuit board problem (fairly rare by all accounts) or far more likely, an issue with the magnets breaking up/covered in debris and causing the throttle butterfly shaft to jam. Easy way to check for the latter is to remove the pipework where it enters the TB, which is just a few jubilee clips and with the ignition OFF, gently push the butterfly to see if it has a full range of movement and operates smoothly whilst also returning to it's original rest position under spring pressure.

With regard to Davy's pedal potentiometer, it's one of the best upgrades you can do, as it will also smooth out the throttle response a little and build in reliability.
 

Twinturbo

Junior Member
Messages
101
#9
Hhmmm, so the throttle butterfly is a little sticky from closed to 20% open then nice and free but there is absolutely no pressure at all to return it to a closed position with ignition off but with ignition on it snaps back to closed,and for further info the right side sensor is magnetti but the left is aftermarket contactless by the looks .


Thanks again everyone its very kind of u all to help out and it's great to have access to like minded enthusiasts to keep these awesome cars going
 
Messages
1,798
#10
Thanks again everyone its very kind of u all to help out and it's great to have access to like minded enthusiasts to keep these awesome cars going
The power of the Forum! its good we could help, many of us know how daunting all of this can seem and a little help never hurts.
 
Messages
187
#11
Hhmmm, so the throttle butterfly is a little sticky from closed to 20% open then nice and free but there is absolutely no pressure at all to return it to a closed position with ignition off but with ignition on it snaps back to closed,and for further info the right side sensor is magnetti but the left is aftermarket contactless by the looks .


Thanks again everyone its very kind of u all to help out and it's great to have access to like minded enthusiasts to keep these awesome cars going
That will be the throttle body then. It should return under it's own steam. If it needs the ignition on then it's the motor that's doing the work of returning it. This results in a 'sticky'/'lumpy' throttle response, which is what I think you're describing. Mike Roberts at Maserati shed does a contactless rebuild which will give you a creamy smooth throttle response.
Can't say for sure that that's the only issue but it sure sounds like one of them.
Steve.
 

allandwf

Centenary Club
Messages
6,961
#12
That will be the throttle body then. It should return under it's own steam. If it needs the ignition on then it's the motor that's doing the work of returning it. This results in a 'sticky'/'lumpy' throttle response, which is what I think you're describing. Mike Roberts at Maserati shed does a contactless rebuild which will give you a creamy smooth throttle response.
Can't say for sure that that's the only issue but it sure sounds like one of them.
Steve.
I think OPs had been to Mike. Perhaps give him a call to confirm butterfly response.
 

MRichards

Junior Member
Messages
76
#13
It seems that the butterfly valve response is not correct. I had my throttle body refurbed by Xemodex in Canada. Their expertise & rapid online service is brilliant and not expensive.
If the previous refurb had been done correctly you would not have the sticky valve problem. Xemodex will fit their own contactless throttle position sensor (yours is probably the cheap Chinese one),rebuild the motor & magnet,fit new butterfly valve bearings and fully test the unit. They give you the test results. Also guarantee the unit.
Their online enquiry service is brilliant,not the appalling "f*ck off" response you got from Mike.
I also bought Davy's contactless pedal pot,but will need to modify the internal spring before I fit it to the car.
 

Twinturbo

Junior Member
Messages
101
#14
Yeah I'm quite confused I bought the car knowing it had the contactless done by mike only to see it fail 2 years later and now Mike is being evasive and a little rude tbh, he says he did the best he could with what he was given but now I don't know if I need an entirely new one as Mike is talking like mine is irrepairable or maybe he just can't accept the job wasn't done right, mine was tampered with before he got it apparently ,but surely a TB can be fixed if the housing is all in tact it s not like the structure of it has been compromised just the internals,and sounds like xemodex does the whole lot anyway?

When u got the TB back from xemodex is it just a bolt on and it works type deal?
Just another question if I bought a used throttle body off eBay could I just bolt that on and it will get it running or does it need calibration and programming ? And if it does how would this be done? I don't have any Maserati specialists near me that's all
Thanks guys
 

MRichards

Junior Member
Messages
76
#15
The refurbed throttle body will bolt on and work properly. Xemodex even supply a new gasket ! (You also get a free Xemodex baseball cap)
As far as I know,and I will stand corrected on this,you can't use another throttle body,since,I believe,your original body has a VIN specific card,so it only works on your car. The diag. available at Maserati dealers allows them to reprogramme another body to work on your car. The throttle body is common to old Volvo cars so there are thousands of them out there and also a thriving refurbishment industry for all the same reasons. A Volvo service technician couldn't tell me whether he could get a Volvo throttle to work on the Maserati.
So the answer to your first question is Yes.
The answer to the second question is No.
I think you estimation of the chap from Maserati Shed is spot-on. I saw him featured on some pommie car restoration TV feature. His work and workplace was sensationally underwhelming,I can't imagine why anyone would trust him with their car.
 

Rex B

Junior Member
Messages
448
#16
Hi

You can use a tb from another car I have just fitted a new one to my 3200 after the old one repaired 7 years ago started giving cells again.
Just because mike repaired the tb it does not mean other items can't go wrong with it. Most contactorless conversions replace the throttle position restisors with a hall sensor but but as others have said the motors can jam or not return under spring pressor and there are some other electronics in the unit that can fail.

If mike can,t help you this time contact David Askew he also repaired tb's . explain that it has been repaired before and see if he can help, he also sometimes has some second had units.

Regards Rex B





tb,s and might also have a second hand unit.
 
Messages
1,798
#17
i have also heard of people trying a spare TB to check out their car with no issues, so i don't think there is any reason you can't fit a different TB to your car. I don't think the 4-wire link between the TB and the ECU is that smart i think its just a position demand that is sent to it and some feedback so the ECU knows what the actual throttle position is.
I got my TB refurbed by Xmodex many years ago now and it bolted on and worked first time no problems, and no funny set up routines or anything. Easier than the pedal sensor set up :)
 

Contigo

Moderator
Messages
16,350
#18
TB is not locked to the VIN as others have confirmed. The way to prove these issues is to borrow a TB from someone with a car which works and try it on yours.
 

Twinturbo

Junior Member
Messages
101
#19
TB is not locked to the VIN as others have confirmed. The way to prove these issues is to borrow a TB from someone with a car which works and try it on yours.
I have a great contact in the UK that looks after me with 2nd hand low
Mileage parts I can pick up a 20,000mile TB negotiating a price ATM but what's failure rate in miles on these is that worth a go considering I only
Drive 5k miles a year on average and with then have my other TB off to get xemodex fixed without having car off the road
Davy I will be purchasing your PP when I sort my TB out thanks for PM I love this live so much and can't wait to have it running well
Again it's got real love at street meets andnso unique here in QLD AUS just the little pesky thinks that letting it down ATM
 

Twinturbo

Junior Member
Messages
101
#20
TB is not locked to the VIN as others have confirmed. The way to prove these issues is to borrow a TB from someone with a car which works and try it on yours.
I have a great contact in the UK that looks after me with 2nd hand low
Mileage parts I can pick up a 20,000mile TB negotiating a price ATM but what's failure rate in miles on these is that worth a go considering I only
Drive 5k miles a year on average and with then have my other TB off to get xemodex fixed without having car off the road
Davy I will be purchasing your PP when I sort my TB out thanks for PM I love this live so much and can't wait to have it running well
Again it's got real love at street meets andnso unique here in QLD AUS just the little pesky thinks that letting it down ATM