any clues?

[bernhund]

Had my car back from Jetstream for a few weeks now but still have a problem with it. I'll be getting it back to Dave for some more investigation soon but in the meantime any clues to what could be wrong? When I pull away in 1st the car feels as though it's about to stall unless I ride the clutch just a little, then while I'm driving the over all sound seems 'deeper' than usual and the whole feel of the car is kind of muted and down on power. Dave fitted new injectors which appear to have solved the 'hunting' issue it went in for, but this is another problem.
Don't know if this is a red herring but when the fans cut in the engine will virtually stall and I'm wondering whether a bad earth could lead to the engine problems if the power getting through is down? Or is this just another fuel problem? Or, God forbid, ECU!

[anotherdom]

Is your idle speed set right? That could cause issues pulling away, and fans will tend to start when you're stationary?

Dom.

[bernhund]

Idle is around 800 and yes the fans usually kick in when stationary, which is why my ignition light starts to flicker and the revs almost hit the deck when I'm sat at a red light..very annoying!!!

[Adrian W]

Vacuume leak

[R0162]

Just to give you some ideas...tickover seems a tad low...and it is normal for rpm to drop when fans come on..but of course it is more of an issue when your revs are already low..would you say the problem with setting off is related to low tickover, trying to stall?

Lots of things can cause lumpy running like that, it could be the air intake manifold is leaking..It could be a problem with your exhaust system, maybe an obstruction or an oxygen sensor gone faulty which is very common, you could try cleaning out the throttle body, are you getting unburnt fuel? you could try cleaning the fuel system or looking at the plugs.....but...
Seen as though you are taking to back to Dave anyway..i would just wait it out if it is still driveable...

[bernhund]

Adrian W said:

Vacuume leak

Interesting...how do I find it though?

[anotherdom]

Probably a more professional way, but a spray of Plus Gas around the manifold joints etc might work.

[XLRONYX]

I use an unlit propane torch with a piece of small diameter tubing taped to the nozzle so that I can poke it between the intake runners. Crack the gas valve so that you can barely hear gas escaping, then hold the hose tip near places that may be leaking. If you have a leak, manifold vacuum will suck propane into the combustion chambers and your idle speed will climb a bit.



Jeff

[Gadgeroonie]

wd40 or brake cleaner does a similar job

[R0162]

easy start..the engine note will change or speed up if it leaking/drawing in air but also just check all your vacuum pipes..look for splits/ holes etc..

[Wooden Horse]

Have a look at the vacuum pipe that fits on the top of the engine. If it's pushed on too far it causes the some of the symptoms you are having. It's a 90 degree bend and in pushed fully on cuts to flow.

[ShiDevil]

No idea if your engine works the same but my 6 cylinder tvr has same issue, it idles ok, as soon as i put foot on accelerator to pull of it judders and tries to stall. Its only relieved by more rpm. it's play in the throttle body, which means first two throttle pots activate and delay in last 4. There is play of about 0.5 cm. They need tightening or rebuilding on mine. Simple to check on
mine under bonnet and manually press down, if all activate together fine if not, then that's issue. Hopefully that makes sense, not the most mechanically minded lol

[anotherdom]

Not an issue on the Noble, we don't have individual throttle bodies!

[ShiDevil]

Ahhh, worth a try lol

[ShiDevil]

Ahhh, worth a try lol