Thread: Engine won't rev for a couple of min when drive selected FO

Mine does this once every few months. Engine won't rev for up to a minute. If turned off and back on always works perfectly.

So, cleaned map sensor and all appeared to be good. Then took it for a drive up the highway only to find it now bogs down after driving.
Disconnecting maf made no difference.
Map was quite clean so sprayed some maf cleaner in it.....does this sound like the map sensor is stuffed?..
Cheers

I have a similar problem but generally happens after driving for a while. Today I drove across a causeway in a steep dip, caravan in tow. As I cleared the causeway & tried to accelerate up the slope, the accelerator went on strike. This time, I couldn't persuade it to work again. Then I selected low range & hey presto all worked again & worked correctly for the rest of the trip today.

It's not the gearbox as I have a reconditioned box 3000 km old in mine & it misbehaved with the old box. My MAF works fine according to Nanocom. I do have an Air Inlet Temperature fault logged.

At my wits end, the problem has caused some hairy moments in traffic towing a 2.7t caravan. Watching with interest.

Originally Posted by Devomorris

So, cleaned map sensor and all appeared to be good. Then took it for a drive up the highway only to find it now bogs down after driving.
Disconnecting maf made no difference.
Map was quite clean so sprayed some maf cleaner in it.....does this sound like the map sensor is stuffed?..
Cheers

Have you checked the vacume lines to and from the turbo modulater? It is also possible the modulater needs replacing. If you disconnect the MAF the system defaults to a factory setting, the nanacom will log a fault, but if all else is oki it should run ok with reduced performance. The maf could be had it the accel could be on the way out. Check the voltages as you drive.

Cheers Scott

Pulled map sensor out again and gave it a shake and put it back in again. Drove to the airport which took about 40 min and ran fine. Father inlaw drove it back again, no issues. Should get a run again this weekend so waiting to hear how she goes. Thinking of throwing in a new map sensor anyway. MR Auto said he's only changed 2 in 12 years! So they're usually very reliable.

Just trying to clarify your symptoms in my head...

If on startup there is no rev change in park when you depress the throttle pedal on and off, or after so many seconds it all seems fine:
*Faulty throttle assembly (typically logs faults under transmission as random non injector response etc etc).

If you have throttle response, it drives but then has a lack of throttle response or starts to surge under heavy throttle:
*Fautly or intermittant MAF (but disconnecting the plug on top it should drive fine)

If it starts/drives fine but randomly it surges especially under full throttle.
*Faulty turbo modulator/vacuum line (actually its pressure not a vacuum), one of three has come off or is split.

If it starts/drives fine but under full throttle surges.
*Stuck waste gate on turbo.

If it starts, but lacks throttle response/dies/struggles when in drive and wont push to 3000rpm or beyond.
*Faulty fuel pump

All of the above/some of the above symptoms.
*Oil ingress in the injector harness/harness plug/loom to computer/ red plug on computer/ oil in the computer (ECU behind battery and requires carefully pulling apart)

The most common from the top:
Fuel pump.
Turbo modulator or the pressure lines to and fro.
Stuck waste gate.
Oil in injector harness plug.
Oil inside computer (ECU).
MAF

Regards
Daz

P.S The two items that wont list fault codes are a faulty fuel pump, faulty MAF

Originally Posted by DazzaTD5

Just trying to clarify your symptoms in my head...

If on startup there is no rev change in park when you depress the throttle pedal on and off, or after so many seconds it all seems fine:
*Faulty throttle assembly (typically logs faults under transmission as random non injector response etc etc).

If you have throttle response, it drives but then has a lack of throttle response or starts to surge under heavy throttle:
*Fautly or intermittant MAF (but disconnecting the plug on top it should drive fine)

If it starts/drives fine but randomly it surges especially under full throttle.
*Faulty turbo modulator/vacuum line (actually its pressure not a vacuum), one of three has come off or is split.

If it starts/drives fine but under full throttle surges.
*Stuck waste gate on turbo.

If it starts, but lacks throttle response/dies/struggles when in drive and wont push to 3000rpm or beyond.
*Faulty fuel pump

All of the above/some of the above symptoms.
*Oil ingress in the injector harness/harness plug/loom to computer/ red plug on computer/ oil in the computer (ECU behind battery and requires carefully pulling apart)

The most common from the top:
Fuel pump.
Turbo modulator or the pressure lines to and fro.
Stuck waste gate.
Oil in injector harness plug.
Oil inside computer (ECU).
MAF

Regards
Daz

P.S The two items that wont list fault codes are a faulty fuel pump, faulty MAF

Strangely, none of these symptoms fit the bill. When my father picked up the car for me, he said that the turbo lag was dangerous. By the time I got my hands on it, he'd disconnected MAF sensor and seemed to be better apart from the first 30 sec or so. ( would rev in either park or neutral but not drive). No faults showed up on the nanocom so reset anything and everything and drove a lot better. Replaced MAF with a VDO unit but didn't seem to change much. Then clean MAP and that changed things again. On start up there was no sluggishness but after it had warmed up there was lag. Clean MAP again and all appeared to be fine. Was driven today for the first time in a couple of weeks without issue. Go figure!