its still a bag of sh*t

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robp38

robp38

Well-Known Member
Posts
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Location
north devon
if i took the exhaust off, leaving manifolds on, should the car run as normal, all be it very noisy, im thinking that it would run badly as the lambda sensors are not sensing anything !!!!

car been on testbook, no faults!!!!!!!!

been told problem is the cats breaking up and blocking the flow of gasses, so im trying to find out if i can test this by taking cats off
 
Hi Rob. I got the voicemail this evening - no mobile signal at work. :doh:

Just to confirm the T4 findings, no trouble codes were logged on the Motronic ECU. All the sensors on live data looked OK, but the fuel trims after an adaptive reset were showing the vehicle was trying to overfuel to compensate for the problem it was having running.

There won't be much of a problem removing the Y section, even with the HO2 sensors being bypassed. Have you tried it yet?

Maybe you need some feedback from people running LPG without cats fitted. From what I understand as long as the vehicle arrives at the testing station on LPG, then the examiner must test the vehicle running LPG, in which case usually the vehicle will pass the test without cats fitted.

I'm wondering why the cats appear to have broken up? To get them to break up on both banks like that, they must have been excessively hot or over fueled. I'd guess most of this damage would have been done before or during the problem which prompted the head gasket work.
 
WSLR said:
Hi Rob. I got the voicemail this evening - no mobile signal at work. :doh:

Just to confirm the T4 findings, no trouble codes were logged on the Motronic ECU. All the sensors on live data looked OK, but the fuel trims after an adaptive reset were showing the vehicle was trying to overfuel to compensate for the problem it was having running.

There won't be much of a problem removing the Y section, even with the HO2 sensors being bypassed. Have you tried it yet?

Maybe you need some feedback from people running LPG without cats fitted. From what I understand as long as the vehicle arrives at the testing station on LPG, then the examiner must test the vehicle running LPG, in which case usually the vehicle will pass the test without cats fitted.

I'm wondering why the cats appear to have broken up? To get them to break up on both banks like that, they must have been excessively hot or over fueled. I'd guess most of this damage would have been done before or during the problem which prompted the head gasket work.
Click to expand...

hi richard

have tried dropping the cats off the manifolds and if anything it runs worse, the revs go up and down and wont tick over.. and wont rev at all from the pedal.. so i was wondering how it would run with the exhaust removed.. (i know it will be very noisy)
 
the cats will have no bearing on the gas, there may be back pressure issues but i dont get any problems with mine.

the cats i knocked out were the original and in a very poor state, your issues are not with the cats!!

can you check to see what brand the lambdas are?

what were the trims at?

its worth checking visually, i remember you did something to it and it was fine for a short while, could this have gone back to its original position?

did you get the cable for the gas?

if you knock your cats out it will sound a little asmatic but other than that there will be very little change.
 
if u had a de-cat and custom exhaust made with one silencer box you would hav solved problem if nt change fuel rail this could allso be problem and has the lpg kit been serviced on old systems it is comon for them to brakedown on rail systems. Is it starigh into rail or port?
 
range2.5dsemad said:
if u had a de-cat and custom exhaust made with one silencer box you would hav solved problem if nt change fuel rail this could allso be problem and has the lpg kit been serviced on old systems it is comon for them to brakedown on rail systems. Is it starigh into rail or port?
Click to expand...


its drilled n ported into manifold.. fuel delivery is ok..overfueling to compensating for whatever problem is !!! was going to get lpg serviced but as its not running right theres no point yet :doh:
 
could be a brake down in system i would get is serviced then see if problem is gone. There are upgrades on old systems to make more afishent. If it is a wet port system check u hav plenty of lubricatsion for system to work afishentley. Cant rember wat it is called but be under ur bonnet and looks lik a fish blow check fliud ok. Petrol engines need to be lubacated at all times
 
The motronic ecu hasn't no ability to reset the adaptive settings. You can only clear faults.
The gems ecu can have adaptive settings reset.
It sounds like the maf sensor has packed up.
 
Rick-the-Pick said:
The motronic ecu hasn't no ability to reset the adaptive settings. You can only clear faults.
The gems ecu can have adaptive settings reset.
It sounds like the maf sensor has packed up.
Click to expand...

Mine has, and I have done it several times with my Faultmate.

Extract from the helpfile......
SM009 - BOSCH MOTRONIC M5.2.1 - Diagnostic Capabilities (Other)


Discovery security learn: This function forces the Motronic ECU to learn the incoming code from the BCU in a Discovery Series II as its correct mobilization code.
Reset adaptive values: The adaptive values should be reset if any of the following components have been renewed or rectified: fuel injector, lambda sensor, fuel pump, fuel rail, MAFS, inlet manifold, after fixing an air leak or if a new ECU was fitted.
Click to expand...
 
Last edited:
robp38 said:
are you saying that the maf can pack up and not show on testbook !!!
Click to expand...

I was saying you can reset the adaptions on the Motronic ECU. Which you should do after changing anything on the air/fuel system. I have some readings somewhere of what a good MAF should be reading at various rev ranges. I will dig them out if you want ? Oh, hold on...found them...

Idle 680rpm - 22Kg
1200rpm - 32.5Kg
2000rpm - 55Kg
3000rpm - 92Kg.

Thanks to 8NV
 
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