P38A Hesitation under light throttle.

I think there may be an issue with the throttle pedel on the dse. Seems to cause intermittent light throttle. Like you have some injectors misfiring but they aren’t. Doesn’t happen if you put cruise on so I think the pedel is sending duff signals is this a common fault?

Bit more information. No injector light on dash and truck drives fine under all other conditions. When I say light throttle I mean just about resting your foot on the pedal.

Possible. They're all getting old. Don't have cruise.

Is the MAP pipe all good?

Don’t know tbh. I’ll have look tomorrow. Runs and idles fine. Think its the TPS. Done some research and that seems like a good culprit

So with unit out I’m looking for another. Found a couple in the bay. One has a slightly different part code even though it came from a P38 dse and looks identical. Mine is 0 205 001 006. The other is 040

Joss155 said:

I think there may be an issue with the throttle pedel on the dse. Seems to cause intermittent light throttle. Like you have some injectors misfiring but they aren’t. Doesn’t happen if you put cruise on so I think the pedel is sending duff signals is this a common fault?

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I had a hesitation on acceleration for years : engine warning would flash on and brief loss of power. I'm sure somebody on here diagnosed it as a needle/valve issue in the engine diesel pump. I had to get the pump refurbished in the summer due to a leak which caused an MOT failure. Problem has disappeared.
(Incidentally I still have a spare pump which I bought and which turned out to have same leak after fitting. Turned into a v expensive job)

Worth a thiught. Did it do it with the crusie control on? Mine very obviously does when it is controlled by my foot but totally disappears at any rev range and speed when crusing. Even at 30 in 5th with bugger all rpm

Joss155 said:

Worth a thiught. Did it do it with the crusie control on? Mine very obviously does when it is controlled by my foot but totally disappears at any rev range and speed when crusing. Even at 30 in 5th with bugger all rpm

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My problem also disappeared in cruise control.

How much to have the pump recon?

Is this a manual?

Yes mate. Diesel manual metal inlet manifold

Joss155 said:

Yes mate. Diesel manual metal inlet manifold

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If it is happening at low rpm in high gears likely DMF flopping about.

Do they not do a solid flywheel yet for the bus?

wammers said:

If it is happening at low rpm in high gears likely DMF flopping about.

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Dual mass flywheel? Well I must admit that wasn’t even on my radar. It is happening at higher rpm. Just light throttle only. It’s not noisy.

Mark Piercy said:

Do they not do a solid flywheel yet for the bus?

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That would be a nice conversion. Did it on my old diesel alfa a few years back. I’ve bought a TPS to see if that solves but I guess there is far more to look at ....

Joss155 said:

Dual mass flywheel? Well I must admit that wasn’t even on my radar. It is happening at higher rpm. Just light throttle only. It’s not noisy.



That would be a nice conversion. Did it on my old diesel alfa a few years back. I’ve bought a TPS to see if that solves but I guess there is far more to look at ....

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Do you not know anyone with a Nanocom to rule out electrical problems? Guessing on these can get quite expensive. Best guess from me would be DMF flopping from side to side and that is really expensive.

No mate unfortunately not. Might have to just invest. Have a mate who owns a garage with a Texa. Talks to every car under the sun except mine!

Joss155 said:

No mate unfortunately not. Might have to just invest. Have a mate who owns a garage with a Texa. Talks to every car under the sun except mine!

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Yep diesel P38s are a one off when it comes to diag. No system on them is OBDII compliant.

Don’t I know it. Still. Lets see what this tps does first and then we’ll go from there

Mark Piercy said:

Do they not do a solid flywheel yet for the bus?

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They do but I wouldn't.

Usually when the DMF is on its way out it is like the clutch is slipping when you floor it in 3rd gear. No EML.

Mines isn’t doing that. I’m light. On DMF’s in general. My156 weasel did 150,000 on it’s original.