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Author Topic: Turbo Diesel Revs limited  (Read 1187 times)

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JamesV6CDX

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Turbo Diesel Revs limited
« on: 14 June 2007, 19:51:52 »
What could be the likely cause of a 2k rev limit - a cam sensor?
« Last Edit: 14 June 2007, 19:52:21 by JamesV6CDX »
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TheBoy

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Re: Turbo Diesel Revs limited
« Reply #1 on: 14 June 2007, 21:11:40 »
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What could be the likely cause of a 2k rev limit - a cam sensor?
Which engine, 2.5TD or 2.0/2.2DTi
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Marks DTM Calib

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Re: Turbo Diesel Revs limited
« Reply #2 on: 14 June 2007, 21:21:34 »
MAF sensor or an inlet pipe detached (check the turbo).

The diesel will only add fuel in proportion to the air going in....if the MAF reports bugger all then little fuel is injected....result....no power and no revs!
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TheBoy

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Re: Turbo Diesel Revs limited
« Reply #3 on: 14 June 2007, 21:30:07 »
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MAF sensor or an inlet pipe detached (check the turbo).

The diesel will only add fuel in proportion to the air going in....if the MAF reports bugger all then little fuel is injected....result....no power and no revs!
In the case of the 2.5TD, I'm not convinced the MAF does much. Earlier ones didn't have a MAF, and I reckon the software is still based on no MAF. Unplugging MAF on mine makes absolutely zero difference, nor does it bring on EML....
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Marks DTM Calib

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Re: Turbo Diesel Revs limited
« Reply #4 on: 14 June 2007, 21:34:52 »
It does one hell of a lot......try disconnecting the hose that feeds the turbo.......
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TheBoy

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Re: Turbo Diesel Revs limited
« Reply #5 on: 14 June 2007, 21:36:48 »
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It does one hell of a lot......try disconnecting the hose that feeds the turbo.......
I meant electronically, the ECU seems to ignore the MAF readings....
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osealy

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Re: Turbo Diesel Revs limited
« Reply #6 on: 14 June 2007, 23:56:36 »
You know the way they they rev them at max rpm for NCT (MOT) seeing as I don't normally do this while driving can I temporarily tech it down to 4k for the test? My tractors are usually 100K plus mls & it cant be good for them!
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Marks DTM Calib

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Re: Turbo Diesel Revs limited
« Reply #7 on: 15 June 2007, 09:17:59 »
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It does one hell of a lot......try disconnecting the hose that feeds the turbo.......
I meant electronically, the ECU seems to ignore the MAF readings....

It does until it decides that there is not enough air to support the quantity of fuel being injected and then it backs off the fueling......this stops the black smoke (unburnt fuel) when nailing it!

Hence.....low MAF reading = less fuel going in = rev limit.
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TheBoy

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Re: Turbo Diesel Revs limited
« Reply #8 on: 15 June 2007, 14:17:51 »
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Quote
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It does one hell of a lot......try disconnecting the hose that feeds the turbo.......
I meant electronically, the ECU seems to ignore the MAF readings....

It does until it decides that there is not enough air to support the quantity of fuel being injected and then it backs off the fueling......this stops the black smoke (unburnt fuel) when nailing it!

Hence.....low MAF reading = less fuel going in = rev limit.
Ah, OK, sort of understand :y

Still, when I forgot to plug the MAF back in on the TD, I didn't notice. No difference at all, including some thrashing (if it is possible to thrash a TD!), and no EML. Strange  :-/
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