Maestro Turbo running funny

[bub]

Just got a maestro turbo 2 weeks ago, driven about 3 times fine before with no problems, then fitted a baileys dump valve and also ive changed from 4star to optimax with ocatane booster at the same time, but i dont think its either of the last 2 things that have been causing this problem as its so intermitant.

basically problem happened last week, took it to work fine (25 miles) but on the way back i had no power, it felt like a car does when it hasnt got the choke out enough when its really cold (but worse) you go to put your foot down slightly and it jolts and doesnt go anywhere, so you have to go really slowly on the peddle (which is not good in rush hour)

took it home and noticed one of the hoses from the inlet mainfold, vacuum bit to the air box/ oil for emissions or whatever had a split in it, so we replaced that pipe and it ran fine, then later it started running funny again.
took it out the next day without touching it and it ran funny but then ok after it got to about half temperature.
so basically its a very intermitant fault, sometimes it could run fine from cold, or run badly then run fine from fully warmed up or badly the whole time out of the last 6 times ive driven it..

can anyone give some suggestions as its putting me off driving it till we can fix it :(

[ben rawlings]

hi and welcome to the forums....

i dont know much about the rover o series motor but have you checked all usual stuff like leads,spark plugs, distributer, filters etc,etc. some pics of the car would be great as a maestro turbo if genuine is a very special motor and it would be nice to see what sort of condition its in.

p.s do you know when the cars last service was and what sort of millage has it got on the clock???

good luck

[G Force]

so basically its a very intermitant fault, sometimes it could run fine from cold, or run badly then run fine from fully warmed up or badly the whole time out of the last 6 times ive driven it..

can anyone give some suggestions as its putting me off driving it till we can fix it :(


Hello bub, because the fault is intermittent I think it could be a problem with the float chamber vent valve. If this valve sticks open it will give the symptoms that you are getting, usually just when the turbo starts to boost you get a feeling like you are running out of petrol.

This valve is an electronic solenoid and is mounted on the bulkhead at the drivers side. The solenoid opens every time you switch off the engine to allow the petrol vapours to vent from the float chamber to make hot restarting easier. When you turn on the ignition the valve closes to ensure that boost pressure can act upon the fuel in the float chamber. If the valve sticks open then once the engine comes on to boost no fuel is delivered to the engine.

To check the valve you can disconnect the pipe from the float chamber to the valve, and if you can blow through the pipe with the ignition on then the valve is sticking or there is a wiring fault. If the valve is sticking you can blank off the pipe at the valve end and see if the car runs properly, but with the pipe blocked you will have difficulty starting when hot.

Cheers Gary:)

[ben rawlings]

Hello bub, because the fault is intermittent I think it could be a problem with the float chamber vent valve. If this valve sticks open it will give the symptoms that you are getting, usually just when the turbo starts to boost you get a feeling like you are running out of petrol.

This valve is an electronic solenoid and is mounted on the bulkhead at the drivers side. The solenoid opens every time you switch off the engine to allow the petrol vapours to vent from the float chamber to make hot restarting easier. When you turn on the ignition the valve closes to ensure that boost pressure can act upon the fuel in the float chamber. If the valve sticks open then once the engine comes on to boost no fuel is delivered to the engine.

To check the valve you can disconnect the pipe from the float chamber to the valve, and if you can blow through the pipe with the ignition on then the valve is sticking or there is a wiring fault. If the valve is sticking you can blank off the pipe at the valve end and see if the car runs properly, but with the pipe blocked you will have difficulty starting when hot.

Cheers Gary:)

i told you i dont know much about the rover o series...lol

[bub]

thanks for the quick and accurate responses guys, definitely be checking that valve, we were pritty sure it wasnt the ignition components, we changed the leads, the spark plugs seemed fine, the rotor arm and dizzy were new and seemed fine, we changed the ht leads and were going re replace the spark plugs with some ngk iridium ones and magancor ht leads..

for pics take a browser to : http://www.btinternet.com/~sletchet/maestro/
its got 75k on the clock and it was serviced quite regularly but it had been sitting for a few years so stuff like the central locking is stiff and doesnt work properly.

will let you know how we get on.

[E_T_V]

Yes that sounds like a likly culprit as it effectively leans the mixture out as the turbo comes on boost, as no extra fuel is added to cope with the increased air pressure.

I hope to see it at some shows. There is usually a space to be had on the club stand if you are a club member.

[Beaker]

Welcome to the forums :beer: Looks like a very nice car, I see you have the square oil filler cap too.

[bub]

Got home tonight and checked out that valve. Took the pipe off the carb and blew down the pipe, vented straight to air as it should. Turned on ignition and tried to blow down pipe but it held pressure. So it was working OK, but as I said it is intermittant. So left pipe off and drove car, symptoms exactly as before, then blocked up tube on carb and all OK again.

So Gary thanks for the diagnosis it was spot on.

Problem now is how to get at the valve and solenoid assembly, it appears to be beneath the servo and hence impossible to get at without removing something - any ideas what the best thing to remove to gain access?

[G Force]

Hi bub, glad you have found the culprit :thumbup:

You could try remove the carb cooling hose to access the valve.

Cheers Gary :)