3200GT starting hard when engine is warmed

[rumen1]

Hi guys, I am having a problem with my 3200GT, that unfortunately no one can help me to fix.

I live in Bulgaria and unfortunately there is no independed specialist here, that has a SD2 tester to see what is happening with the car and in the same time the people from the official dealership of Maserati in Bulgaria are saying, that they know only the newer cars and they see a 3200GT for the first time. They have made a diagnosys and haven't found any engine errors, but obviously something is wrong with the car...

The problem is, that on cold start the engine starts perfect, but if I leave the car for about 40-50 minutes or more, it starts very hard, something like when the engine mixture is rich. On cold wetter the problem is smaller, but this summer it was really obvious! The idle is also not very stable.

We have some good mechanics here, but none of them can read the car and like I said - the people, who can read it, don't know what to do with it.

Does anyone have a clue what this may be? I was thinking about a temp. sensor, but it seemed to show normal temperatures when the dealership made the diagnosys...

 

[CatmanV2]

When you say 'if I leave the car for about 40-50 minutes or more, it starts very hard' do you mean 'after it's been running for 40-50 minutes' so when the engine is hot?

That might well be the crank sensor. 3200 experts will be along in a minute.

C

 

[Contigo]

Crank sensor or air leak in O ring seal under the Plenum.

Ask Maserati for the fault codes!

 

[NickP]

Is there a fault code? Is the CEL on? Not sure what is meant by starting hard? There is an issue with a few of these, mine included, where if I've driven it for a while, then stall it or stop, it won't start again for 2 minutes. Bit of a pain when sitting across a junction. I did read on here ages ago what the fault was but for the life of me can't remember. A sensor of some sort I think.

The workaround is to wait 2 minutes without trying to restart and the car starts straight away. Not sure if this is what you are experiencing but sounds similar...


Must get round to fixing this one day. The cure is to change the sensor, I'll try and find which one it is.

 

[jluis]

Mine does the same and I haven't got around to look at it in detail.
Doesn't throw any codes, it just won't start when hot
Last summer it was a pain in the 4ss but this winter the problem has not showed itself (although it's in hibernation, I do take it out every now and then)

What I see in mine is that when it's hot, if I do the reset procedure (turn off the battery on the isolator for 10 or 20 seconds and then on again) the car will start without issues.

Try that on yours to see how it goes.

Also, you could try opening the fuel cap to release pressure.
EVAP systems are prone to failure due to age and this might allow gasoline gases from evaporation on the tank to be fed to the plennum at all times therefore generating a rich condition on startup consistent with what you see.

 

[jluis]

Is there a fault code? Is the CEL on? Not sure what is meant by starting hard? There is an issue with a few of these, mine included, where if I've driven it for a while, then stall it or stop, it won't start again for 2 minutes. Bit of a pain when sitting across a junction. I did read on here ages ago what the fault was but for the life of me can't remember. A sensor of some sort I think.

The workaround is to wait 2 minutes without trying to restart and the car starts straight away. Not sure if this is what you are experiencing but sounds similar...


Must get round to fixing this one day. The cure is to change the sensor, I'll try and find which one it is.

It can be the coolant sensor or the camshaft sensor.
Coolant sensor sends an incorrect temperature reading therefore messing up the mixture and the camshaft sensor is used to sense engine phase and I believe it's only used on startup (to determine TDC)
Some people point to the crankshaft sensor but I'm not very convinced on this as it would cause the car to die or run roughly if the sensor was missing some reads.
I did change the crankshaft sensor on mine, just because it was cheap and I could eliminate that possible source.

 

[Tompelli]

Similar to my situation a month ago. Get the nagging feeling that poor battery condition started it all off. You are probably struggling with more than one fault if your idle is also unstable. Back to basics, start at the battery & check everything. Definitely worth having another try at the diagnostics.

 

[davy83]

There are a few good suggestions here. the fact it idles unevenly suggests either problems with the throttle body, pedal sensor or air leaks around the plenum. All of these are prone to failure. The large cover under the plenum can create problems as the screws vibrate loose, and need to be put back with a new gasket and some thread-lock compound. CAM sensor is an easy and cheap one to replace and can cause problems, and the cranks sensor does some funny things when its broken and is clearly used by the ECU for a lot more than it should be, but not sure it fits your symptoms. engine temperature sensor is a very common failure and would certainly cause some problems. Unfortunately i suspect the uneven idle and the poor starting when warm may be two separate problems, so try to keep this possibility in mind. The poor starting when warm i would go for the engine temperature sensor to be honest, its a piece of junk, and fails because of the heat under the bonnet.

 

[rumen1]

Thank you all for the replies. What I mean is that no matter for how long I have driven the car - if the engine is warmed up - after I shut it down and wait for more than, say, 30 minutes, it starts hard. By starting hard I mean, that the starter motor turns, but the engine stalls and does not want to start from the first time. It starts from the second time and with a lot of turning by the starter motor.

When checking the car by Maserati (the only thing they could do) there were no error codes from the ECU (and I have no CEL on the dash). I actually have а printout from the sensor readings when the car was at idle, I can upload them here tomorrow (forgot them in the car).

I will check about leakings under the plenum, but the throttle body and the gas pedal potentiometer are not the issue for sure, because the throttle body has been rebuild by Mike from Maseratished and I have also bought a contactless gas pedal potentiometer from davy83. The battery is almost new.

UNFORTUNATELY today a knocking sound from the engine has appeared and my engine may be for an overhaul... Just can't believe this - more than an year without ANY issues and now all problems at the same time... I will also need an info if there are any alternative engine parts for the 3200 (pistons, bearings), because this may be expensive. The oil smells on gasoline, but I guess this is because of the rich fuel mixture.

I apologize, that I only ask questions. For the moment I am only a consumer in this forum and I can not help anyone, but I hope with the time I will have some experiense to help others too.

 

[Contigo]

Sorry to hear that mate! All parts available from eurospares but get it checked as these engines are strong! What sort of knock is it?

 

[jluis]

Would be nice to hear that sound or have a description of it.
Does the engine run with the knocking noise? Is it constant?
Does it affect performance when it's running?

Knocking sounds can be a lot of things like detonation under load, valve clearances or bearings, loose parts, etc

Is your car hard to start when hot immediately after being shut off or only after a prolonged time switched off and with the engine still being warm?
What year is it?

 

[rumen1]

Sounds like a constant knock on the upper side (around the right hand head). It appeared today after a 30-minute drive. The engine works fine, but knocks. I am afraid to take her out and push it, I don't if it is a good idea to start it again actually. The car is '99.

We will take the engine apart and see what it is. The parts will be the problem in this case, but the good side (if there is any) is that at least no diagnosys will be needed for this. However, after the fix (or a new engine, I don't know), maybe the starting problems will remain. And also I am preparing for at least 2 months waiting.

 

[jluis]

Don't start assuming the worst.
Valve lash will do that, although should not happen all the sudden.

Take out the intake, the valve covers and timing belt cover.
Check first for any loose screw on the plenum and then check valve clearance and engine timing.

 

[rumen1]

OK, the engine has finally been removed from the car and opened. All pistons look OK and there is only a little play in them, that my mechanic finds as normal. The honing seems perfect, there is no damage anywhere on the block or the pistons. He thinks, that the problem is somewhere in the heads, but there is nothing generally wrong in them also. He thinks, that the problem may be solved by a good adjust of the valves. So now we will make a total revision of the heads and I hope that will solve the knocking.

In the mean time I ordered some sensors from Eurospares, that I hope may help for the starting problem, but they have told me, that the 3200 water temperature sensor is not available from Maserati anymore. Does anyone know where can I find it?

 

[StuartW]

Good progress there

Try David Askew for the temp sensor www.davidaskew.co.uk

 

[rumen1]

Unfortunately even he hasn't got a new one. This sensor is out of production and no supplier anywhere has it new. However, I have saw the Magneti Marelli number on mine and managed to find an alternative one.

 

[EnzoMC]

if hot issue then this could be temp sensor which others have suggested, could be thermostat

how old is the battery ?
a quick and easy check is battery and cheap fix if not good. these cars need a good supply, a poor battery will not supply enough amps even if battery is 100% charged.

the starter motor will pull the amps needed and may not enough left to run the other sensors, therefore not able to start.

 

[rumen1]

Battery is 1 year old, so is the thermostat. i have bought almost all important sensors, including the temp sensor, so we will see what will happen. Thanks for the help.

 

[EnzoMC]

Battery is 1 year old, so is the thermostat. i have bought almost all important sensors, including the temp sensor, so we will see what will happen. Thanks for the help.

was battery replacement as per manual - for GS needs to be minimum of 74ah and cca 700 - could be same for 3200 ?

 

[rumen1]

I don't remember, to be honest, but it is big for sure. I have also tested it and it gives the right charge.