P38A Engine speed dropping at tick over

Buzz2406 · May 16, 2016

Hi all,

Just noticed something today with the rangie. It is a 1998 2.5 dse automatic and the problem is that on tick over the engine speed drops to a point that it feels like it will stall but doesn't. The feeling is very similar to having a manual gearbox at tick over but lifting the clutch to the point that it engages but leaving your foot firmly on the brakes. It does it fairly regularly for a while as warming up then seems to stop. I intend to get it on a diagnostic but initially any thoughts??

Cheers

Buzz

Saint.V8 · May 16, 2016

I am no expert (Wammers is yer man for that) But could be the fuel quantity servo thingy....the revs may dip slightly as drive is engaged, but the EDC on the Diesel models is actually very good and the revs should pick up almost straight away back to a stable idle.

wammers · May 16, 2016

Buzz2406 said:
Hi all,

Just noticed something today with the rangie. It is a 1998 2.5 dse automatic and the problem is that on tick over the engine speed drops to a point that it feels like it will stall but doesn't. The feeling is very similar to having a manual gearbox at tick over but lifting the clutch to the point that it engages but leaving your foot firmly on the brakes. It does it fairly regularly for a while as warming up then seems to stop. I intend to get it on a diagnostic but initially any thoughts??

Cheers

Buzz

What is the normal idle speed of your engine when warm?

Buzz2406 · May 16, 2016

About 600 pm.

wammers · May 16, 2016

Buzz2406 said:
About 600 pm.

Much to slow, get someone with a Nanocom to lift it to 750. Setting should be 750 plus or minus 50. Ideally 750 constant. Should be set to 128 on pump calibration settings. If it is at 128 on Nanocom and giving 600 RPM warm engine, has someone been playing with the pump top?

Buzz2406 · May 16, 2016

Ahhh cheers Wammers. Will check it out on diagnostic and get it adjusted. Many thanks

Buzz2406 · May 16, 2016

Not aware of anyone playing with it and too chicken to fiddle myself.

wammers · May 16, 2016

Buzz2406 said:
Not aware of anyone playing with it and too chicken to fiddle myself.

Two minute job to reset it.

Buzz2406 · May 16, 2016

wammers said:
Two minute job to reset it.

Cheers. Just as an aside. If this was the case would it account for my engine management light flashing on when I lift off the accelerator?

wammers · May 16, 2016

Buzz2406 said:
Cheers. Just as an aside. If this was the case would it account for my engine management light flashing on when I lift off the accelerator?

Mil lamp coming on when lifting off or when coming out of cruise control is usually a quantity servo problem. Get a Nanocom on it and read any fault codes that are present. Get idle set to 750. See what you get then. If calibration is set to 128 and you have 600 RPM idle warm engine you may have fault codes.

Buzz2406 · May 16, 2016

Cheers Wammers. Will get it checked out.

Grrrrrr · May 16, 2016

Might be worth checking the lift pump is kicking out the right amount too. Wammers did a How To in the technical section.

revs will drop a bit as the air-con clutch kicks in. Press the AC button so the orange light is on (light on means AC off!) and revs should be stable, well, more stable.

Buzz2406 · May 17, 2016

Cheers Grrrr. Plan to have a look at the weekend

P38A Engine speed dropping at tick over

Buzz2406

Member

Saint.V8

Dyed-in-the-wool 100% RR Junkie

wammers

No longer with us, RIP

Buzz2406

Member

wammers

No longer with us, RIP

Buzz2406

Member

Buzz2406

Member

wammers

No longer with us, RIP

Buzz2406

Member

wammers

No longer with us, RIP

Buzz2406

Member

Grrrrrr

Technician, Bodgit & Scarper Ltd

Buzz2406

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