Shock and Awe - 3200 Throttle Issues.

[Ian3200]

A footnote to Mike's response... I've suggested things that might need doing on my car and Mike has talked me out of getting him to do the work, as the problem I've suggested is not what's causing my issue. He could have taken way more money from me than he has over the years, he's honest and genuine and will always want you to contact him to deal with your issue if you've had work done by him, rather than second guess anything. He will fix stuff that's broken after a thorough diagnosis, not just replace stuff until something works.
Just wish he wasn't so popular sometimes!

 

[Roberts Aerospace]

And don't send Mike someone else's TB (ie one which has previously been worked on ) as 9 times out of 10 he won't repair it.

I'll always attempt to fix one that has had an attempted repair by someone else, but, I may not be successful as irreparable damage may have occurred. It's always best to start with one that hasn't been opened and messed around with.

At some point though, I may have to start charging extra for ETBs that arrive having been opened, as they always require extra work to fix them.

Mike.

 

[redsonnylee]

I'll always attempt to fix one that has had an attempted repair by someone else, but, I may not be successful as irreparable damage may have occurred. It's always best to start with one that hasn't been opened and messed around with.

At some point though, I may have to start charging extra for ETBs that arrive having been opened, as they always require extra work to fix them.

Mike.

Mine was poorly refurbished, Mike did a fantastic job carrying out remedial work. So feel very fortunate.

Had a horrendous 3 hour drive in bumper to bumper traffic last week along the M25/M23, the car was faultless the entire journey

 

[boomerang]

I'll always attempt to fix one that has had an attempted repair by someone else, but, I may not be successful as irreparable damage may have occurred. It's always best to start with one that hasn't been opened and messed around with.

At some point though, I may have to start charging extra for ETBs that arrive having been opened, as they always require extra work to fix them.

Mike.

Exactly my thoughts lately.

In my experience, faulty electronic modules where almost always taken from units that where opened before.
In case of a faulty module, all is lost.

 

[urquattrogus]

Oh dear, this seems to be a very irregular problem.

Mike is on the case and has been doing Stirling job of logging all kinds of data and doing lot's of tests, but the issue is still there.

In a nutshell it revs up to 3000 revs on start-up.

Initial report was as follws:

Under certain circumstances, the vehicle will rev to c3000 RPM on starting. The circumstances are as follows:
The car must have been previously started.
The power to the ETB must have been cut off after the car has been off for a few seconds.
The gearbox must be in P or N. As soon as it is put into D or R, the problem goes away and doesn't return.
If the car has stopped and is immediately restarted, it is ok. The "clack" as the ETB depower must have
occurred for the overrev to happen. It also behaves normally if the car is cold.

He has proven the the cause of the high revs is that the ECU is requesting it, no faults with the throttle body and or pedal pot etc.

Latest line of inquiry is the TCU requesting something...

 

[davy83]

Its Italian !!! you may need to live with this i think they all do this once in a while.

Oh dear, this seems to be a very irregular problem.

Mike is on the case and has been doing Stirling job of logging all kinds of data and doing lot's of tests, but the issue is still there.

In a nutshell it revs up to 3000 revs on start-up.

Initial report was as follws:

Under certain circumstances, the vehicle will rev to c3000 RPM on starting. The circumstances are as follows:
The car must have been previously started.
The power to the ETB must have been cut off after the car has been off for a few seconds.
The gearbox must be in P or N. As soon as it is put into D or R, the problem goes away and doesn't return.
If the car has stopped and is immediately restarted, it is ok. The "clack" as the ETB depower must have
occurred for the overrev to happen. It also behaves normally if the car is cold.

He has proven the the cause of the high revs is that the ECU is requesting it, no faults with the throttle body and or pedal pot etc.

Latest line of inquiry is the TCU requesting something...

 

[Contigo]

Battery replacement would be my first port of call. I e seen under voltage cause these issues, has he re-calibrated the pedal pot to the TB? Ray on here had the same issue and Emblem re calibrated it which fixed over revving.

 

[mchristyuk]

I'd agree with Phil. Try a new battery. I had a battery which started the car fine but it ran like ****. Put a new Bosch unit in and it transformed the car. A friend in the hot Subaru scene says the same with their cars....

Mark

 

[urquattrogus]

TB etc all re calibrated.

I doubt it's the batterry, 12.6v at rest and 14.4v when running when i checked it. Car spins over nicely.

not with car, so can't drop test it, but I am sure he would take batterry into account...

it runs well otherwise....

 

[boomerang]

At this moment i have a TB in with very strange manners.
The rotor in this TB was very stuck, so the electronics must have had quite a job geting it moving.
As soon as it is getting hot, problems occur.
I will exchange its module for testing but i am sure that its module is shot.

Module faillure can never be ruled out.....

 

[urquattrogus]

Mike says the car does the same with other Throttle bodies, inc a new genuine item.

It's just so irregular that I was hoping someone could comment that has had the same issue etc

 

[Contigo]

Yes Ray on here had exactly the issue you describe and took the car to Emblem. Ask Mike to recalibrate. It involves plugging in at the throttle potentiometer itself.

To quote.

"The 3200 with the sticky throttle was registering pedal pressed within engine parameters making it rev at idle, I adjusted the pedal stops on the throttle pedal to zero the readings and cleaned the connection. I then reset the pedal parameters and carried out an engine adaptive value reset. This procedure hadn’t been done for a long time so it had a very positive effect on the way the car ran!"

 

[Contigo]

Oh and when it happens again get your foot and stick it under the acclerator pedal and lift it up, I bet the rev drops down to normal!

http://www.sportsmaserati.co.uk/showthread.php/19418-Throttle-Sticking?highlight=lovellracing

 

[davy83]

yes very sensitive to the position the pedal returns to. also the calibration of the pedal sensor, i would do it 3 or 4 times a year to be honest, it is so sensitive that the change in the weather can affect it.

 

[urquattrogus]

None of these apply I'm afraid. They have been checked by Mike.

 

[urquattrogus]

Still no cigar - it looks like I am going to have to live with this annoying problem and have the car back.

In fairness to Mike, I think he has tried everything he can think of and collected a lot of data.

 

[boomerang]

That is bad news.
Somehow i think i have had a car for repair once that did that too.
But it must have been solved with the contactless TB back then.

Thought a lot about your issue.
Is there any fault stored, immediately after this behaviour?
I would be interested to hear if the butterfly of the TB is realy in a more opened position if it runs 3000 rpm.
And what happens if you try to close the butterfly by hand a little at that time and do you feel the TB making an effort to open the butterfly again then?
If so, the ecu must think 3000 is the rpm to maintain, while it isnt.
Did you measure (with a scope)the signals of the TDC sensor and did you compare it with the signal of another car?
Something funny must be going on there.

 

[alfatwo]

Still no cigar - it looks like I am going to have to live with this annoying problem and have the car back.

In fairness to Mike, I think he has tried everything he can think of and collected a lot of data.

Before we start.. lets not forget Maser weren't the only ones with the early 3200GT Magneti Marelli drive be wire Can Bus engine management systems

There must be lots of interesting technical stuff out there if you know where to look!


Dave

 

[CatmanV2]

Before we start.. lets not forget Maser weren't the only ones with the early 3200GT Magneti Marelli drive be wire Can Bus engine management systems

There must be lots of interesting technical stuff out there if you know where to look!


Dave

I diagnosed my gearbox issues with Jaguar technical data sheets

C

 

[allandwf]

Good call, do a search on Volvo and revving on start up. They used the same system, and the symptoms were reasonably common.