p38 running problems help

hello all hope some 1 can help i have just bought a n reg p38 4 ltr with lpg conversion with a dream xx1 system on it and was all running fine till a few weeks ago and have now got a miss fire on both gas and petrol and cant seem to resolve the problem i was getting aroung 200 miles from about 60 ltrs of gas and now gone down to 125 ish and poor response up hills and poping back through air filter and only seems to go well when kicked down and reving hard !
i have replce plugs with BPR6ES AND GAPPED TO 0.63 MM AND REPLCED THE LEEDS AND NOT MUCH DIFF IN PERFOMANCE I HAVE STRIPPED DOWN THE GAS INJECTORS AND CLEANED AS FAULT WAS GAS TO START WITH BUT NOW SEEMS TO BE BOTH AND NOT MUCH BETTER BUT SOME DIFF I HAVE SPRAYED LEADS AND COILS WITH WATER TO C IF THERE IS A MISS BUT ALL SEEMS FINE I HAVE PUT ON CO MACHINE AND GOT A VERY HIGH CO LEVEL ABOUT 6 TO 7 % AND ALSO PLUGED IN MY OBD11 READER I HAVE CODES FOR KNOCK SENSORS ON BOTH BANKS AND ALSO HAVE A LOW MAF READING OF 0.7 ON IDLE AND ABOUT 1.5G/S UNDER HEAVY LOAD NOT SURE IF THATS RIGHT BUT I HAVE FITTED NEW MAF TO CAR BUT NO CHANGE ONLY A CHEAP 1 FROM EBAY I HAVE ALSO NOTICED I HAVE NO VOLTAGE FROM O2 SENSOR BANK 2 BUT SIGNAL OF AROUND 5 TO 600 AT ABOUT 70 MPH ON 02 SENSOR BANK 1 THE GAS WIRRING IS ONLY CONNECTED TO 1 O2 SENSOR FOR SOME REASON NOT SURE Y ,HAS ANY 1 GOT ANY IDEAR OF THE MAF READING FOR THIS ENGINE OR ANY GOOD IDEARS WHERE TO GO WITH IT NEXT APART FROM SCRAP YARD LOL:doh:

Engine Temp Sensor faulty ???????????????

gauge seems to be reading all ok and no diff from when it was running good i have spoke to a main dealer today and advised me the cams of lifters wear but the engine has only done 40,000 from a new engine replacement thanks hooded claw !!!

broomy1702 said:

gauge seems to be reading all ok and no diff from when it was running good i have spoke to a main dealer today and advised me the cams of lifters wear but the engine has only done 40,000 from a new engine replacement thanks hooded claw !!!

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The gauge reading "Normal" does not necessarliry mean the Engine Temp Sensor is reading correctly .. the temp sensor supplies its readings to the BeCM & thense the BeCM "Adjusts" the various imputs to the engine....

Wammers will be along in a bit to further this "Idea" ... hes BRILL at this sorta thing & has explained it before on here with great clarity....

TONY!!..............Over to you mate ..........................

Thank you Keith. Ok, temp sensor Keith means is ECU temp sensor, not the one for the dash guage. One for dash usually brown in colour. ECU sender usually blue in colour. This sensor along with inlet air temp sensor controls fuelling at various temperatures. It is not the only thing that goes wrong but is the obvious first one to try on ECU controlled engines.

See, Broomy ... I said he was good !!!............ Thanks Tony

Thanks guys i will have a look monday when i get back to work and i seee what ya mean hooded and thanks wammers

Poor running on gas will throw the ecu adaptions out so it will run bad on petrol. Get it running well on the petrol first. 1 Throw away the MAF and get a genuine one, the cheap ones are just that and you will be flogging a dead horse. 2 Get the fuelling adaptions re-set. 3 Check for air leaks around the intake manifold by spraying carb cleaner around the joints, any increase in idle will be indicitive of a leak. 4 Check both O2sensors with a voltmeter you should see them cycling between 1v and 5v every second or so. Do this then report back.

silly question but have you checked compressions? Mine had a blow across 2 and 4 cyl and and that ran better at higher revs,also low mpg.

sorry guys computer packed up and only just got back on line have now nearly got to the bottom of the prob put new lambda sensensors on and got it running alot better and also put new leads and coil pack on and runs much better but i dont seem to get good mpg from the gas about 130 miles from 90litre tank does any 1 get better than this if so how many thanks for all the help every 1

Get it tuned at your local lpg centre. Mine was the same before my bag load of other trouble started.

Hi, double check the condition of the wires and pins on the mutiplug to the coil packs from the engine harness.
90 litres is nearly 20 gallons x 14mpg = 280 miles !

ill check the pins and pop down the local lpg place and c what they can do 4 me thanks

I get 120miles around town on 45lt of gas with a single point system,and over 140 on a run.

hello guys sorry its been a while but back to the poor old p38 i still have issues with the poor fuel eco and have today put new ecu temp sensor on which i belive is the 1 on front of in let manifold and the dash guage 1 is next to it disconected the dash 1 to make sure it was the right 1 ? i have been checking the fuel trims and and have on idle shrtft 24.4 % on both banks and the longft ihave -100.0% the shrtft seems to change at reves and about 70 mph and goes to 0.0 up to about 10 % ish i have also put a gen maf sensor back on and took off the cheap 1 any idears why the furl trim seem to be stuck and not move im guessing its over fueling and i do seem to get knock sensor faults keep coming back into memory any words of wisdom wise ones on this thanks broomy

forgot to say that i have also checked lamda reading and they seem lazy there about 0.15 on idle and only going up to 0.25 when doing about 70 ish on live data readings

my p38 range rover is also bloody thirsty,less than 19 mpg,no leaks starts well,120 thousand miles,is it knackered,no smoke either,but it does seem to go ok,full service inc fuel filter and new thermostat,but still bloody thirsty.

id be pleased with 19mpg

So would I. I doubt I'd get that at a steady 70 on a flat motorway.

broomy

Interested to see how you get on. I am currently getting 12 mpg on gas. Obviously the thing needs some serious investigation and may well start out with new ECU Temp Sensor. Do you have a part #, source and cost for the one you got ?