[gurx]

funny car

sometime it is running fine......apart from in 6th gear it is cutting at 120km/h......all the time

but....somteimes it has no performance at all.........not in any gear........car has no dpf....no fault codes, no warning lights...only one it gave us p0234 and p0238.......replace suction control valve....still the same, checked the vacuum box............can't get it right


any idea?????????

 

[k-4]

Suction control valve goes in the back of the fuel pump mate
It controls the fuel pressure and it sounds like its going into limp mode
Do a search there's loads of info about it

 

[JPMC]

Those codes relate back to the turbo.

p0234 is the boost control solenoid valve that is located behind the air filter and activates the turbo.

p0238 is the boost sensor located down on the exitside of the intercooler.


The boost control solenoid is a known problem so maybe you should be looking at that.

 

[gurx]

scv replaced yesterday...no change.....so next boost control?

 

[JPMC]

scv replaced yesterday...no change.....so next boost control?

Did you reset the fuel pump or ECU after replacing it?

 

[gurx]

nope

 

[JPMC]

Try resetting the fuel pump before wasting more money as when you replace the suction control valve the fuel pump needs to adjust itself for the pressure change.

Do this by following the instructions below.

Turn ignition on so all dash lights come on.

Wait 3 seconds.

PUMP accelerator pedal 5 times within 5 seconds....

With foot now OFF accelerator wait 7 seconds...

After 7 seconds press and hold down accelerator pedal for 10 seconds...

After 10 seconds the Engine Management Light will start to flash, at this point remove foot from accelerator.

The Nav is now in diagnostics mode, so let the EML flash for a bit. Then press and hold the accelerator pedal down for more than 10 seconds - this will then reset ECU and fuel pump etc and put them into learning mode.

 

[gurx]

doesn't seem to be the problem....sorry.....we changed two scv, one new one used, both reset/learned as described......still doing the following:
you drive with normal power, come to a e.g. robot (slowing down) accelerate again and whoop....no power.....no warning lights or dtc's either (very seldom p0238). you stop the car/engine off.....restart... everything fine again for a short period........

we removed the cat, as we thought it could be a blocked cat - note: the car does not have a dpf!)..........any other idea(s)??????????

 

[gurx]

boost control was also replaced........

ecm/ecu left???

 

[landmannnn]

I had the fuel rail replaced under warranty, showing similar symptoms.

 

[gurx]

the complete rail or just the pressure sensor?

 

[landmannnn]

Whole rail.

 

[lookskyward1]

This is an interesting post, it may be worth a try.
viewtopic.php?f=14&t=25496&hilit=scv

 

[gurx]

hi....great...that sounds like a plan.....will try it and report back......easier to do this than to replace a costly rail.... :+1