Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[05omegav6]

That should put a light on, being electrical... basically whenever the ecu sees summat it doesn't like, it will try to compensate, and failing that put a light on. No lights means one of two things... either the bulb has blown or the issue is in a system that the ecu cannot see.

I'd be surprised if the output from the throttle pedal isn't monitored in some way, but it's essentially a variable resistor which might be failing, causing odd throttle responses sticking throttle body might be another cause...

[zirk]

Could be Maf, but as said that should put alight on, might not if the Maf still reading, be it inaccurately, but I wouldn't expect a Maf fail to give those symptoms your describing.

 

[zirk]

Im trying to picture in my mind what would cause your sudden stopping (being slammed forward) during a miss fire, without any braking involved, the only thing I can think off is your miss fire is total Ing. fail (no spark on all pots), or as Al's thinking, total Fuel fail, although I would have thought enough fuel pressure left in the system to run it down rather than a complete cut out. May be not if being hammered.

I wondering if its worth checking and re installing the 2 ECU plugs and checking the main wiring  connectors under the battery, you could also swap the purple relays over, see if that does anything (if was me I would pop the covers off and have a look at the relay contacts), and generally checking, wiring loom, pushing relays fuses in the box.

Other thoughts, ECU??, I have had 2 go now on 3.2's without fault codes, one intermittent, the other total fail over night. 

[Andy H]

Could be Maf, but as said that should put alight on, might not if the Maf still reading, be it inaccurately, but I wouldn't expect a Maf fail to give those symptoms your describing.

If the MAF gets oil on it it may still be OK electrically but feed duff readings to the ECU. Worth checking the long term fuel trims to see if the ECU has tried to adapt to misleading air flow readings.

[dbug]

Just disconnet maf and see if it cures fault - if it does replacement maf required

[TheBoy]

Do you still have the old airfilter and a spare MAF for testing?  Oiled filters are known to destroy MAFs - on the 2.6/3.2 this tends to be an under reading, rather than a "not working", hence no codes.

What are long term fuel trims doing?

[P6UL K]

Do you still have the old airfilter and a spare MAF for testing?  Oiled filters are known to destroy MAFs - on the 2.6/3.2 this tends to be an under reading, rather than a "not working", hence no codes.

What are long term fuel trims doing?

The what now?

Yeah I still have it all but it's been doing this long before the fitting of the K&N

[cem_devecioglu]

A 3.2 ECU is intelligent enough to create cylinder misfire codes if ignition problems cause a misfire, unlike the 2.5/3.0.

Which is why I didn't say loom, as that definitely generates codes...

Another thought, is the fuel light on/less than 1/4 tank what speed are you doing when this happens? Accelerating?

Top of the red to run out is about 5 miles at full chat and fuel starvation is about the only thing which won't put a light on...

I tought similiar but once started fuel starvation problems wll show very frequently and you can easily guess


I still think the ignition feed is cut completely for some reason

[05omegav6]

Could be a left over from the runlock wiring I suppose

[TheBoy]

I still think the ignition feed is cut completely for some reason

Knowing the Motronic 3.1.1, I'd expect ignition codes for that, unless the entire ECU is shutting down.

[chrisgixer]

Ime the 3.2/2.6 ecu shuts off a cylinder(s) completely until ignition off and re start.

So I doubt its ignition, unless the loom plug is loose? But again, no codes.... Have you seen constant flashing from the pedal trick/car spanner light?

If experiencing loss of drive under full power or firm acceleration, that would throw you forward, so to speak. Without braking. Especially in a manual as reverse load is more severe.

Fuel trims are a figure allocated to the amount of mixture adjustment the ecu is applying to get fuel air ratio correct. Normally around zero, if they are off you might see +5 or -10 as a variance for example. If the maf is miss reporting air volume, a fuel trim figure of more than, say, +or- 5 might support a faulty maf diagnosis.

But them again, if the trims go out by +/- 25 that would bring a warning light on, and the pedal trick would show the specific code.

Has the engine management light bulb been removed? Say to hide a pre cat code 0420/0430?

[TheBoy]

Fuel trims are a figure allocated to the amount of mixture adjustment the ecu is applying to get fuel air ratio correct. Normally around zero, if they are off you might see +5 or -10 as a variance for example. If the maf is miss reporting air volume, a fuel trim figure of more than, say, +or- 5 might support a faulty maf diagnosis.

But them again, if the trims go out by +/- 25 that would bring a warning light on, and the pedal trick would show the specific code.

To update that, for a non-LPG car, long term trims more that -1% - +1% indicates a problem with mixture, as seen by ECU.

Code gets stored around +-20%, EML on at 25%



(LPG adds its own complications that we'll ignore as not relevant to OP)

[P6UL K]

Interesting information regarding the Fuel trims but how would I go about seeing the figures to be able to advise you as to what they are?

Car came to a complete standstill on the A2 last night, misfire got so bad that the car was struggling to run and pull its own weight up a slight hill. Its seriously over fuelling as well, I drove roughly 20 or so miles last night and managed to use just over a quarter of a tank! It's popping and banging on gearchange almost like the car has anti-lag! Okay might not be to that extreme but that's the best example I can think off to explain what is happening.

It's been suggested to me that because I have altered the air intake system the car is drawing in too much air now and the MAF can't monitor it's enough to adapt the Fuel Settings? And to make matters worse I meant to be driving to Cornwall on holiday on Monday morning so I've now got to try and sort out a doner or hire car!!

[zirk]

Interesting information regarding the Fuel trims but how would I go about seeing the figures to be able to advise you as to what they are?

Car came to a complete standstill on the A2 last night, misfire got so bad that the car was struggling to run and pull its own weight up a slight hill. Its seriously over fuelling as well, I drove roughly 20 or so miles last night and managed to use just over a quarter of a tank! It's popping and banging on gearchange almost like the car has anti-lag! Okay might not be to that extreme but that's the best example I can think off to explain what is happening.

It's been suggested to me that because I have altered the air intake system the car is drawing in too much air now and the MAF can't monitor it's enough to adapt the Fuel Settings? And to make matters worse I meant to be driving to Cornwall on holiday on Monday morning so I've now got to try and sort out a doner or hire car!!

Should the Air Intake increase the ECU will compensate for it and add the correct fuel ratio. As asked a few posts up, is the K and N heavily Oiled?

[05omegav6]

Interesting information regarding the Fuel trims but how would I go about seeing the figures to be able to advise you as to what they are?

Car came to a complete standstill on the A2 last night, misfire got so bad that the car was struggling to run and pull its own weight up a slight hill. Its seriously over fuelling as well, I drove roughly 20 or so miles last night and managed to use just over a quarter of a tank! It's popping and banging on gearchange almost like the car has anti-lag! Okay might not be to that extreme but that's the best example I can think off to explain what is happening.

It's been suggested to me that because I have altered the air intake system the car is drawing in too much air now and the MAF can't monitor it's enough to adapt the Fuel Settings? And to make matters worse I meant to be driving to Cornwall on holiday on Monday morning so I've now got to try and sort out a doner or hire car!!

In that case, refit the old induction system and see if that cures it