P38A head repair,power loss

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Wazzajnr said:
I know, I was just thinking that as the revs build and the turbo spools up, the pressure increase could cause more air to escape thus making it super rich? If the head has been off, it could be a gasket on the inlet tract not sealing properly?
Click to expand...

Not quite. First the ECU has to know that manifold pressure is increasing, only then is fuel increased to suit. Sounds from his latest comments he is getting fuel starvation. He needs to check that lift pump is working, if it is, then for a blocked filter.
 
ta for all the replies
I checked the valve timing just in case and it seems to be ok,was a bit worried as first time ive played with the camshaft etc.
Ive changed the fuel filter and whilst it was off I put a jug under the empty fuel head and switched on the ignition. The pump operated for about sixteen seconds then cut out ,in that time I recorded about 200 cc of fuel.
Tried it again to see if it was the fuel filter but still the same. I had the nanacom on whilst I checked it and it recorded the following
fuel flow value out of range
type:-invalid fault,major fault,log

now I used the injectors that came with the second hand head,should I change them for the injectors from my original head as although on that head she would over pressurise she always ran, revved well
 
rover75lover said:
ta for all the replies
I checked the valve timing just in case and it seems to be ok,was a bit worried as first time ive played with the camshaft etc.
Ive changed the fuel filter and whilst it was off I put a jug under the empty fuel head and switched on the ignition. The pump operated for about sixteen seconds then cut out ,in that time I recorded about 200 cc of fuel.
Tried it again to see if it was the fuel filter but still the same. I had the nanacom on whilst I checked it and it recorded the following
fuel flow value out of range
type:-invalid fault,major fault,log

now I used the injectors that came with the second hand head,should I change them for the injectors from my original head as although on that head she would over pressurise she always ran, revved well
Click to expand...

Should produce 180 Ml of fuel in 10 seconds so pump is ok. I will ask again, does the boost pressure rise as engine is revved? What is the modulation at idle warm engine? Change the injectors see what you get.
 
Last edited:
many thanks wammers,ill check the boost pressure rise on revving later I did get the following last night,before I saw your post that is
fuel temp 29.12
swg set point {mv} 3200
swg actual {mv} 2760
inj setpoint degrees 1.8
inj.actual degrees 1.9
timing modulation 73.31.

whilst checking the timing, turning the engine backwards then turning forward to make sure I had the correct hole etc ,I noticed there seems an awful lot of backlash in the timing chain system. The top one is tensioned ok. is this normal? Plus it seems weird that the tensioner is on the drive side of the chain. Is this a german thing as I know they do it on their combines as well which is different from non german manufactured machines,sorry a bit of the point I know
 
rover75lover said:
many thanks wammers,ill check the boost pressure rise on revving later I did get the following last night,before I saw your post that is
fuel temp 29.12
swg set point {mv} 3200
swg actual {mv} 2760
inj setpoint degrees 1.8
inj.actual degrees 1.9
timing modulation 73.31.

whilst checking the timing, turning the engine backwards then turning forward to make sure I had the correct hole etc ,I noticed there seems an awful lot of backlash in the timing chain system. The top one is tensioned ok. is this normal? Plus it seems weird that the tensioner is on the drive side of the chain. Is this a german thing as I know they do it on their combines as well which is different from non german manufactured machines,sorry a bit of the point I know
Click to expand...

Static is slightly retarded at 73.31. I take it that is at idle warm engine. You should NEVER EVER turn them backwards other than a slight nudge to locate locking pin. With old worn chains it can jump the crank sprocket.. Always turn them clockwise, follow instructions in RAVE. DO NOT follow timing directions in BMW M51 engine manual..Tensioners are not on the drive side of the chain.
 
Ta for that.
Checked the boost pressure and it rises as I rev up
at one point it read 180 boost pressure and
ambient was 105
but these varied as I revved
I removed the fuel pump relay ,waited some time then revved up,still the same result . The fuel tank is 3/4 full if that helps
 
rover75lover said:
Ta for that.
Checked the boost pressure and it rises as I rev up
at one point it read 180 boost pressure and
ambient was 105
but these varied as I revved
I removed the fuel pump relay ,waited some time then revved up,still the same result . The fuel tank is 3/4 full if that helps
Click to expand...

If you press the floppy disk icon on the Nanocom when in the EDC screen you can then take a live trace of all the readings as a CSV file. Sometimes useful.
 
Wazzajnr said:
If you have an SD card fitted that is!!
Click to expand...

Forgotten that! Assume everyone has one! On mine I also have the Nanocom manuals, a PDF copy of RAVE and the Nanocom emergency restore files should the worst happen to the unit. Together with the laptop I am ready for most Nanocom related eventualities.
 
solved
got pretty peeved of and threatened the ole girl to drive her off a cliff i was that wound up.
Went back to basics and started all over.
Checked my air filter....again,all good,checked my pipes ...again all good,took the filter off the diesel head and checked the fuel flow again all good.
took the inlet pipe off and the turbo spins ok by hand and to be honest you can hear ,feel the turbo working.
I remembered a long time ago that she would cut out at anything over 3200 start smoking and "misfiring" and it turned out to be the air filter soggy and collapsing,so i triple checked the air filter again but as it was new two days ago it was fine.
Really peeved off now,so disconnected the pipe from the air filter box to the hard plastic pipe over the engine.
Tried here and hey ho works fine. Couldnt understand it,so i took the air filter out ,connected the pipe to the air filter and problem back again,revs to 4200 cuts out ,misfires,smokes.
It turned out the air filter box inlet was almost full of crud,cleaned it all out fitted the filter and hey ho ,all good.
Thinking about it,i work in really dusty conditions so should have considered it. Yes i do wash her regularly
Thanks to all who contributed
 
rover75lover said:
solved
got pretty peeved of and threatened the ole girl to drive her off a cliff i was that wound up.
Went back to basics and started all over.
Checked my air filter....again,all good,checked my pipes ...again all good,took the filter off the diesel head and checked the fuel flow again all good.
took the inlet pipe off and the turbo spins ok by hand and to be honest you can hear ,feel the turbo working.
I remembered a long time ago that she would cut out at anything over 3200 start smoking and "misfiring" and it turned out to be the air filter soggy and collapsing,so i triple checked the air filter again but as it was new two days ago it was fine.
Really peeved off now,so disconnected the pipe from the air filter box to the hard plastic pipe over the engine.
Tried here and hey ho works fine. Couldnt understand it,so i took the air filter out ,connected the pipe to the air filter and problem back again,revs to 4200 cuts out ,misfires,smokes.
It turned out the air filter box inlet was almost full of crud,cleaned it all out fitted the filter and hey ho ,all good.
Thinking about it,i work in really dusty conditions so should have considered it. Yes i do wash her regularly
Thanks to all who contributed
Click to expand...

Well done glad you sorted it.
 
its a swine of a dust,silica quarrying for the high spec asphalt used on the roads. If you spray it with water it just becomes a sludge. A lot of the service vans on site carry a spare i think its a maf sensor as the dust is so abrasive it wears them out in 4-5 months!!! Not nice stuff
 
rover75lover said:
its a swine of a dust,silica quarrying for the high spec asphalt used on the roads. If you spray it with water it just becomes a sludge. A lot of the service vans on site carry a spare i think its a maf sensor as the dust is so abrasive it wears them out in 4-5 months!!! Not nice stuff
Click to expand...

Just think how much your lungs are enjoying it.
 
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