Outer Limits 4x4 Board

Hey Guys

One of my mates has a 3.9 v8 d1 which runs fine when you start it up but when the motor warms up a bit it starts to run poorly. If you are sitting at the lights you have to keep one foot on the accelerator and the other on the brake to keep it running. It just cuts out otherwise because it idles so rough. We first thought that it just needed a tune but when it went in to get that done the guys at the mechanics said that there was a problem with the air flow sensor. It has been to many mechanics now and no one can seem to fix the problem. The air flow sensor has been changed with a second hand one off a wreck that we have that ran fine before it was stripped down but that didnt seem to change anything. Some of the other mechanics have said that the coolant temp sensor might be what is at fault. If anyone has any ideas or had this happen to them before then a bit of help would be welcome

Cheers!

huh what do you mean by that?

air flow meter might need rebuilding/tuning

Try cleaning the Idle Air Control valve at the back of the manifold. Also, plugs, leads, dissy cap. It was one of those that fixed mine, can't quite recall now..

Find a rover guy to look at it - most normal mechanics have no idea - I highly recommend Rovertech at Brendale.

possible stickky valves see it all the time

The ignition is ok? Cap, rotor, leads and plugs?

What model is it?
Flappy or MAF?

I would get a can of "start your bastard"/"break cleaner" and spray it over all hoses on your EFI and if there is a leak the revs will go "up"/"down".

If you cant find any leaks, unplug the air flow meter at running motor and see if there is any difference. If there are difference, the air flow meter is ok.

As next a would spray some WD40/Inox in your idle control.
Sometimes it make them go again for a short while.

The water temp sensor could be defect, but it wouldn't make that much difference for the idle. But you can easy check that with a multimeter. Short circut or open circut means defect.

If your EFI is ok, than have a look to your engine like dundee already said. After 200.000 km the cam shaft is anyway down.

Hope that helps

Chris

Same thing happened to my 93 LSE, I was advised to change water temp sensor by experience rangie mech and problem solved. Car runs fine cold as water temp is saying car cold, but when it warms up it still says cold and computer is running car too rich. Black smoke and ruff as guts idle. Also pull plug of air flow meter several times. These terminals get dirty and loose contact.
good luck.
Russell.

Same thing happened on my 93 classic, it turned out to be the idle stepper motor i got it replaced and she runs sweet !

Knew I shouldn't have posted in this thread - now mine has started doing it again - off to the doctor!!

closet1092004 wrote:Knew I shouldn't have posted in this thread - now mine has started doing it again - off to the doctor!!

New throttle position sensor fixed it - wow $225 for such a little switch!!

Some of the other mechanics have said that the coolant temp sensor might be what is at fault. -- you can checked that in 20 sec with your multimeter.. ,so dont trust that fellas - Looks like they dont know anything about was they talking...

It is maybe the useless and hopeless rover engine, if the engine has more than 160tkm on the clock!
This engines are totaly lost.
The cam is down and the rest of the '67 engine maybe too.
Swap - the best what you can do!
But dont swap to an other hopeless Rover engine like a 3.9, 4.0 or a 4.6!
Sorry to all proud Rover freaks like me - but i have testet them out - Rovers are very nice but the engines, gearboxes and axles are the last s**t!

Go a decent V8 like a LSx and something else than Rover axles (Nissan or Toyota).

Sorry for that -

Chris

when it warms up it still says cold and computer is running car too rich. Black smoke and ruff as guts idle

mine was doing that and ended up being the air mass meter

put a 2nd hand one on and never run so good