3200GT - stalling coming up to junction

[ledlights]

Hi All,

I've had a long standing problem with my car in that it sometimes stalls coming up to junctions. As far as I've noticed, the fault usually happens during the warm-up phase and occurs when I change down gear i.e. the revs overshoot the idle point and the ECU can't recover it.

I've tried to get to the bottom of this for a while to no avail - a change of both lambdas have reduced the frequency of the fault but it still happens occasionally. The idle is a steady 850-900 rpm when warm but when revved the overshoot causes it to hunt for a second or two before it stabilises (it's always done that since I bought it in 2006).

The car has a contactless TB, 2 new lambdas and a new temperature sender fitted. I usually keep the car with the battery disconnected, as I don't use it as my daily drive, and have wondered about the effect of this on the advance/retard setting of the ignition..... Also, normal operating temperature is about 70C so the thermostat could be due for a change.

Any ideas?

Thanks,

Steve

 

[Rex B]

Steve

I assume its a manual?

I have a 3200 manual with a contactotless TB, it has had new lambda sensors and the temperature range is 70 running on the motorway and 90 around town. I have never had any trouble with stalling and it could be the fact that you are disconnecting the battery, and that the ECU which has a self learning function could be having to relearn some of the setting and the stalling is a function of the learning process. The way to check this would be to leave the battery connected and use the car at weekends and give if possible connect the battery to a trickle charger in the week. Mine stays in the garage forall week and I only have to put the charger once a month for a couple of days to bring the battery up to maximum again.

Something else worth checking would be the Throttle pedal voltage is within the range of 0.35 and 0.5 volts at idle, this is checked with the ignition switched on and the peddle at rest.

Regards

Rex B.

 

[conaero]

...I would also have the plugs out and have a look they could be sooted up where you keep removing the battery and the ecu has to relearn again, worth a quick look.

Also have a look at the MAF and chuck some new fuel in her and stop disconnecting the battery, see if that helps.

 

[lozcb]

Hi All,

I've had a long standing problem with my car in that it sometimes stalls coming up to junctions. As far as I've noticed, the fault usually happens during the warm-up phase and occurs when I change down gear i.e. the revs overshoot the idle point and the ECU can't recover it.

I've tried to get to the bottom of this for a while to no avail - a change of both lambdas have reduced the frequency of the fault but it still happens occasionally. The idle is a steady 850-900 rpm when warm but when revved the overshoot causes it to hunt for a second or two before it stabilises (it's always done that since I bought it in 2006).

The car has a contactless TB, 2 new lambdas and a new temperature sender fitted. I usually keep the car with the battery disconnected, as I don't use it as my daily drive, and have wondered about the effect of this on the advance/retard setting of the ignition..... Also, normal operating temperature is about 70C so the thermostat could be due for a change.

Any ideas?

Thanks,

Steve

May i ask what Lambda's you used , were they genuine Maserati ones or a generic model, sounds definately along the lines of lamda's/Maf , we have had a few people that have tried the cheaper generic lamda's which results in frequent problems

Possible air leak on the vacuum system ,could be a possibility



regards loz

 

[stradaman]

Agree, Use proper lambas. Buy Bosch, as they are OE. But, as its cold, it will be in open loop, so lambas not used.
And yes, could have a leak, until engine warms up, and leak disappears. Any small extra air getting in, will cause havoc.
Doesn't the 3200 use an EGR valve? This could be faulty, and cause it also.

Andy.

 

[davy83]

900 rpm sounds a little slow for tick over. pedal sensor might be a problem if its dropping below 0.35 v when you take your foot off the pedal. check black to yellow i think on the connector. Unlikely this would be worse when the car is hot.

 

[ledlights]

Thanks for all the ideas fellas.

The Lambdas were Bosch with the correct plug, so shouldn't be causing a problem.

I'll check the plugs and try leaving the battery connected for a while and see if that solves it. If it doesn't I'll move onto the search for an inlet leak - I've looked before but next time I'll remove it and have a really good look.

Also, I've tried the pedal pot mod recommended by Marcel3200 but to no avail, though it prob wasn't necessary as I hadn't had any pedal pot problems before......

I'll report what gives.

Thanks,

Steve

 

[boomerang]

Maybe worth a check: the bottom of the intakemanifold tends to get loose over time.
I have seen some with bolts missing!
If there is an airleak there, problems like these can occur.

 

[saintetienne]

fwiw , I have manual owned since 2006 too - do the same with battery as not daily driver - more like once a week or 2 - with no issues , as above air leak sounds possible - stalling is characteristic of weak mixture

 

[Fat Arnie]

Are you remembering to de-clutch?




Mine only stalls pulling away when I am not paying attention to the throttle, which even in my 2001 car, has appalling mapping, sensitivity and progression.

 

[LeeH]

Are you remembering to de-clutch?




Mine only stalls pulling away when I am not paying attention to the throttle, which even in my 2001 car, has appalling mapping, sensitivity and progression.

With Boomerangs contactless TB and Davy83 contactless pedal pot mine pulls away without even needing to touch the throttle its is so smooth.

Makes my manual a joy to drive now, worthwhile upgrades even if your not having issues as the enhanced drive is worth it...

 

[ledlights]

Yes mine's pretty smooth pulling away too.

I'll have another look for an air leak. I did the plenum plate a couple of years ago but It could have come loose again even with loctite. When I changed the TB to one rebuilt by Boomerang, the problem did improve.

Considering how long I've had the car, it's been pretty good so I shouldn't complain..... It did have the factory plastic on the carpets though.....

Thanks,

Steve

 

[bill]

As well as the air leaks I would check the throttlebody butterfly moves freaky. With the ignition off,the butterfly should be partly open, at the idle position. Using your fingers, make sure the butterfly returns freely to this position from both fully open and fully closed positions.

Good luck!

 

[ledlights]

I know i put up the original post a long time ago but I've been too tied up with work to get to the bottom of the problem. In the end I took off the plenum yesterday to find that when the plate was put back on by an indie, they clamped it down with an o-ring out of its groove.... End result: cut o-ring on number 8 and stalling coming up to a junction which appeared a short while after the work!

Hope this helps someone else if they end up with the same fault and thanks to everyone who contributed (and bragging rights to those who suggested an inlet leak).

Regards,

Steve

 

[saintetienne]

I know i put up the original post a long time ago but I've been too tied up with work to get to the bottom of the problem. In the end I took off the plenum yesterday to find that when the plate was put back on by an indie, they clamped it down with an o-ring out of its groove.... End result: cut o-ring on number 8 and stalling coming up to a junction which appeared a short while after the work!

Hope this helps someone else if they end up with the same fault and thanks to everyone who contributed (and bragging rights to those who suggested an inlet leak).

Regards,

Steve

That's great news Steve - it's great to solve an ongoing problem after a length of time trying - satifying as well when you find the cause as you did. Just cured my boot leak as well - took a while .

Happy Days ,

Steve

 

[Parisien]

Steve....what was the root cause(s) of the leak....do share!!!!????


P

 

[saintetienne]

Steve....what was the root cause(s) of the leak....do share!!!!????


P

Everyone's called Steve !

Behind the rear bumper you have two channels that are sort of sculpted into rear panel - they have a seam there too - don't know if this will affect everyone ; but my car is always parked nose down . Water ran down behind rear bumper and collected on the top of these channels ,the seam sealer was slightly porous and you could see droplets of water coming through into the back panel then the rain down under the foam and carpet after a while the level rose ......

 

[Parisien]

Steve....gee...am impressed......no pics taken at the time tho? Many thanks regardless!

P

 

[saintetienne]

No sadly I did not think about that till later , that photo is a golden oldie ! - but we have had some rough weather over the last few days and the seems seem ! to be holding well , I have left main well carpet out at moment so I can be sure before finishing . I have found a photo which shows the "ledge" on the rear panel , water collected on here and migrated through the sealer.
Hope this helps others .

 

[bill]

I know i put up the original post a long time ago but I've been too tied up with work to get to the bottom of the problem. In the end I took off the plenum yesterday to find that when the plate was put back on by an indie, they clamped it down with an o-ring out of its groove.... End result: cut o-ring on number 8 and stalling coming up to a junction which appeared a short while after the work!

Hope this helps someone else if they end up with the same fault and thanks to everyone who contributed (and bragging rights to those who suggested an inlet leak).

Regards,

Steve

frustrating I am sure..... but thats great news!