Poor idle, car cutting out at junction / low speed.

Poor idle, car cutting out at junction / low speed.

Author
Discussion

Scarface1

Original Poster:

84 posts

210 months

Sunday 29th May 2016
quotequote all
Hi all.

So I recently got my 4.2 running after some time off the road.
It was running and Reving rough but previous owner had had it fault read as lambda's so I have swapped them both.
It now starts and revs great when stationary and not under load.
However when driving it seams to hesitate until 2000-2500 rpm then takes off and when you throttle off to change gear or pull up to a junction etc the revs die and it cuts out unless you keep revs up.

Any ideas before I book into a specialist?

Thanks in advance for any help.

Steve

pmessling

2,284 posts

202 months

Sunday 29th May 2016
quotequote all
I would from experience still say lambda having had one go after a rolling road session with similar behaviour. Have you plugged in the diagnostics and monitored what they are doing.

tofts

411 posts

155 months

Monday 30th May 2016
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If you have replace the lambdas with new I cant see them being an issue any longer. It sounds more like your throttle bodies and/or tps sensors are out of adjustment!

Hoofy

76,253 posts

281 months

Monday 30th May 2016
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Split in air hose?

I had similar last week on another car.

FarmyardPants

4,099 posts

217 months

Monday 30th May 2016
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Check that the lambdas plugs are not swapped over.

Jabbah

1,331 posts

153 months

Tuesday 31st May 2016
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Scarface1 said:
However when driving it seams to hesitate until 2000-2500 rpm then takes off and when you throttle off to change gear or pull up to a junction etc the revs die and it cuts out unless you keep revs up.
I had very similar behaviour last year. Connected it up to diagnostics software and turned out to be a one of the TPSs. When the engine was warm it would start giving spurious signals translating as spikes of throttle causing over fueling and stalling the engine. Easiest way to diagnose it without diag software is to unplug one of the TPSs and see if it is worse or better then reconnect and try the other. If only the one TPS is connected the other is used for both banks.

Scarface1

Original Poster:

84 posts

210 months

Thursday 2nd June 2016
quotequote all
Hi Guys.

Thanks very much for your replys.

We adjusted the throttle stop slightly so the idle is set at 1100 (any less and it stalls) and it now drives ok.

I have spoken to Racing green and APM and will be getting it in for a set up if I dont find some one local to plug in and reset my ecu etc.

Thanks again.

Steve