You have discounted the MAF haven't you?
You have discounted the MAF haven't you?
No need to separate the coils to test, just unplug them at the multiplug. MAF is another one that can cause weird things to happen, unplug it and see if there is any difference, if not, that is you likely problem area. Bear in mind that the fuel injectors, MAF and Camshaft sensor are all powered from a common Brown/Orange 12V rail while the coolant temperature sensor, fuel temperature sensor, lambda sensors, intake air sensor and throttle position sensor are all powered from a common 5V rail on a Red/Black supply,
Idling fine but dying when you open the throttle may also point to the TPS as it controls the idle air valve making it open at small throttle openings to raise the revs above idle. TPS voltage can easily be tested with ignition on and engine not running just by moving the throttle while watching the voltage on the Nano.
i have visually inspected and cleaned the maff . can it be tested with a multimeter ?have ordered the coil pack as my testing says it's stuffed , will take some time to arrive so i might tackle some of the other small issues , blower motors.
MAF output to the ECM should be in the range of 1 - 5V, 1.4V at idle.
A dead MAF will usually lead to the engine starting and then stalling.
One way to check it, unplug it and see if the problem is worse/different/better/same/insert some other thought here ......
engine stalling 4.0L gems watch video.
i have removed the coil pack so at present unable to try and start wit maff disconnected
Does it always run for roughly the same length of time before dying? Will it die even if you don't touch the throttle? Fuel pressure maybe? Fuel pump primes when you turn the ignition on but doesn't run once the engine starts? Put a gauge on the Schrader valve and watch what it does. Does it show full pressure when you switch it on and then maintain it while running or does the pressure drop off?
Fuel pressure seems like a good bet, i agree
have checked the fuel pressure it is 37psi at idle and 38psi at run . the vehicle hasn't been started for days and still has pressure at the rail
the video was taken from a cold start as it seems to run for a longer period before stalling and then starts and stops as per the video . no throttle just start run stall. i have checked all things that i can check and the only thing that i have found faulty is the coil pack
PS i have put the video up because all the good helpful info has been deleted and we need to develop our own library of info again.
ok time for an update , coils arrived , fitted and guess what its not the coils (testing them wrong) . cracked it and walked away in disgust even though i know it wasn't the coils . went back later in the day started up and sounded different , would rev with slight miss managed to move the metal island out of the driveway and under cover .
have now made a loom up so i can pin test the maf without damaging the wires or the plugs. hopefully this will happen today when i have an assistant to assist
PS how to test a TWIN output coil,
primary coil is tested by probing the inputs , negative on negative ,positive on positive multimeter on 200 ohms should read around .5 to 1.4 or their abouts , mine read around 1.1
secondary coil test is done bye probing BOTH the hi outs (where the leads come out of the coil) mutti meter on 20k ohms place the positive and negative on the two outputs , reading should be around 8k to 15k ohms or thereabouts, old coil read 11.3k ohms , new coil reads 13.8k ohms. not shore if that makes it stronger or weaker with the old coil reading lower
now have to check out the maf , will report back later.
ok now it's later , time to report . have tested the maf several times and have different readings . first readings were very erratic jumping from 1.5v to around 3 to 4v just idling , smocked me out of the carport in 20 seconds , end of that test . tried again to day and the reading was a lot more stable siting around 1.5 v to 1.65v but would not alter , other than the slight fluctuation it would not move ,. didn't smoke me out this time so i was able to be more pacific with the readings, so i am looking for a new MAF . have looked on line and the price varies from $120 to $300 but they look the same brand just a different supplier , is there any recommendations when purchasing a new MAF or are they all the same anyway.
yes it's a gems
If it is a GEMS, perhaps looking for a couple of S/H ones as I understand the replacement ones, all from China, aren't all that good. I picked up a couple of S/H ones from a wrecker in Geelong, swapped them in and out to find that I they work OK, so they can sit on the spares shelf.
have borrowed a maf from a friend , all is working ok now so it is definitely the maf .
That's good then, a simple and relatively inexpensive fix.
Is a 2nd hand maf better than a cheap Chinese New version
Most definitely yes, second hand ones are likely to work. Chinese ones work but give the wrong readings so the fuel trims go all over the place.
This isn't a Rangerover specific answer but I'd say yes for most vehicles for the same reason Gilbert said.
Recently had a similar discussion on LpgForum regards a supercharged L322, seems many of the vehicle's problems were caused by an aftermarket 'compatible' MAF, which went away when the genuine part was fitted.
Super. Cheers guys.
ok i am looking for another maf not an easy find at moment will keep looking, if anyone comes across one please let me know thanks.
Don't know if this link will work
But this chap I have sourced quite a few second hand parts from on ebay.
He doesn't list the Lucas Mafs that often but he does have plenty of them by all accounts.
Perhaps worth messaging him directly and see what he says.