G60 cuts out and slugish at hi revs

[LozBoz 0]

HELP!

Above 4000 rpm my G60 has started to cut out, it feels like you have hit the rev limiter and won't accelerate. It is also generally slugish. It only seems to do this at or near full throttle. It also only seems to do it once it is warm.

I have checked all the vacuum pipe work.

Changed the entire ignition system.

Changed the blue coolant sensor.(when you remove the plug at idle it stalls the engine is that right)

Changed the fuel filter.

Checked the timing. (is it 6 degrees before tdc and do you need to remove any sensor plugs to get it right)

Checked the fuel pressure.

Had a diagnostic test (flash test).

It still does it. Please help me i am really stuck

:x

[W3RKD 0]

timing should be set with blue cts removed and car up to temp and @ 2k-2400 rpm.

[LozBoz 0]

Ahh a person in the know.

Got a garage to do the timing. Don't trust them though.

I have a timing light to do it myself. How do i know it is at 6 degrees is the arrow near the pulley meant to line up with the groove on the pulley at 6 degrees BTDC or do you have to guess at 6 degrees before that point. The revs drop off dramatically when i remove the blue temp sensor plug killing the engine at idle. Is that right?

[Jim 2]

It should struggle, but the engine should be able to cope without it cutting out - when checking timing, both mine and Tempests G60's dropped to about 550RPM...

[LozBoz 0]

Right, the timing is definately right. so is the cam timing.

Where do i go next?

[stevemac 0]

There's a good DIY section to work your way through here - http://www.snstuning.com

 

Does the engine get progressively worse as the revs increase ??

 

As Jim says, with the blue temp sensor disconected the engine should still idle & not cut out. If it does cut out then you still have a timing problem - what you will need to find is the cause.

 

Connecting the blue temp sender enables the ECU to make corrective timing adjustments based on various signals taken from different sender units on the engine. Favourite to fail is the ECU vacuum pipe which connects to the back of the throttle body. This MUST measure exactly 1m in length. Worth replacing - costs around £6 from the stealer & will eliminate this as a cause.

[h100vw 0]

If it starts to die when you disconnect the Blue temp plug, Wind out the tickover screw til it holds. Reste this when you have done the timing.

Gavin

[LozBoz 0]

Changed that vacuum pipe to the ECU that was my first point of call. The timing is correct. although it still die's when i unplug the blue sensor. Checked the air flow sensor too got a figure of 219 Ohms is that ok?

[h100vw 0]

Did you turn the screw out??? When you disconnect the blue plug the idle stab valve doesn't control the tickover. This allows you to set it and the ISV can then do its job properly.

Gavin

[W3RKD 0]

Changed that vacuum pipe to the ECU that was my first point of call. The timing is correct. although it still die's when i unplug the blue sensor. Checked the air flow sensor too got a figure of 219 Ohms is that ok?

 

a rough base guide should be between 550-600 on a standard car.. this is just a base figure though.

[Timo. 0]

Changed that vacuum pipe to the ECU that was my first point of call. The timing is correct. although it still die's when i unplug the blue sensor. Checked the air flow sensor too got a figure of 219 Ohms is that ok?

 

a rough base guide should be between 550-600 on a standard car.. this is just a base figure though.

 

What does changing the resistance of that actually do? I set mine to 500 ohms when I was having a few problems with my g60 after I first got it. It could really do with a proper tune up but there's no where decent that's near me!! :cry:

 

The resistance was actually set a wee bit higher than that as I made a note of it incase by changing it, it screwed everything up. What would be a "rough guide" setup for a engine with 68mm pulley and chip. Just a ball park, I know its really needs fine adjustment!!

 

Cheers

 

Timo.

[bazgreener 0]

This is exactly the same as my car is doing, have tried various things and not made any difference. I do think i have narrowed things down a bit though, it seems to be heat related as when i have been driving in traffic and then get out on the dual carriageway it will do it but after i have been at speed for a bit and some air has cooled that crappy little intercooler down the car will be ok, i guess this could be the ecu retarding the ignition timing ??? :roll: I don`t hear any pinking though and my air fuel gauge and boost gauge don`t show any different readings. I have a 68mm pulley and sns chip with pressure regulator. The car has only started doing this in the hot weather this summer, when did your problems start Lozboz? Am hoping to sort out a front mount soon so will see if that makes the problem go away.

 

Baz

[LozBoz 0]

Did you turn the screw out??? When you disconnect the blue plug the idle stab valve doesn't control the tickover. This allows you to set it and the ISV can then do its job properly.

Gavin

 

Are you talking about the air flow sensor? If so i haven't touched the screw does the engine need to be hot to adjust this? you've lost me a bit gavin. Set what when the blue plug is disconnected so the isv can do it's job properly?

Yeh it did start doing it in the summer months it does it at night when it has cooled down though Bazgreener.

Tried the SNStuning trouble shooting looks like i might have a vacuum leak. Don't know where to start there. All the pipe work looks good if it doesn't i've replaced it. i take it a vacuum leak would have to be engine side of the butterfly valve and boost would be the other side.

[h100vw 0]

When you disconnect the blue plug the engine should not die, as it sounds like yours is. To set the tickover, disconnect the blue plug, adjust the screw on the back of the throttle body til the car idles on its own. Then reconnect the blue plug. You need to do this with the engine warm really, so be very careful as the inlet manifold will be pretty hot.

 

The ISV controls the tickover with signals from the ECU. When the ECU detects the throttle is closed, microswitch on the throttle body, it maintains a steady tickover by opening and closing the ISV. Any load on the engine, such as turning the steering wheel or turning on electrical accessories, will require the ISV to open briefly to prevent the PS pump/accessory causing the engine to stall. When the steering comes to rest then the ISV will close again to prevent the engine speed increasing too high.

 

You cant make any other adjustments really, until the engine runs with the plug disconnected.

 

Setting the mixture screw to 500 ohms is a nominal value that works for 90% of cars. This is NOT a substitute for adjustment of the mixture, with reference to a CO meter. But as not everyone has access to one, then it will be adequate in most cases.

 

For finding a vaccum leak I often use WD40. Squirt some around the gasket joints. If the engine sucks a bit in then the revs will rise slightly/the engine note will change.

 

If the leak is not on the manifold then you could try a solution of washing up liquid, make it pretty thick and apply it to all the joints from the charger onwards. Rev the engine, any leaks will cause bubbles to form and Bob's your uncle. This won't work on the inlet manifold as the bubbles will be out of sight!! :mrgreen:

 

Also, is your ECU pipe a metre long? Most important point that!

 

Gavin

[kongo127 0]

All resistence values are taken at ambient temperature. 8)

Be sure to take the CO2 Pot out of the car to adjust it. :idea:

Or just do the checking in the morning! :mrgreen:

[bazgreener 0]

I disconnected my blue sensor and the revs went "up" from 750 to 900 ish, I wound the screw in on the throttle body until the idle dropped to about 750 rpm then reconnected the sensor. The car feels better in traffic now smoother and less jerky when coming on and off the throttle, will see if it has any effect on the power problem though.

 

Barrie