Running but still doesn't seem right.

Had another look at my p38 since I put the plug leads on the right way and still doesn't sound right to me. I went out and it started first time, I thought mint it's improved. So I left it running abit, it was idling about 600rpm, bit of condensation out the exhaust which is as expected from its first start up for a couple of months. Then the rev needle started fluctuating only within a couple of rpm each side of 600rpm. So I thought I'll blip the throttle just to see if it will pick up, and it cut out. Started first crack and it started kicking out black smoke like it used to. If you blip it then rev it , it will pick up and you can hold the revs on all the way round, it just seems abit hesitant on initial pressing of the throttle. Haven't tried it in gear yet, but I'm 70% sure it will cut out when gears are selected. Anyone come across this problem with theirs? Doesn't seem as bad as it was before I took the heads off to check them and disconnected the gas system.

dont suppose you have the obd software to see whats apening in the engine?

could it be the fuel map is all out?

see if you can give it a few miles see what happens. make sure plug leads are on correctly, easy to get em not quite home and cause issues. as for the black smoke its usually over fueling! but could just be soot. if you have obd stuff have a look at fuel trims and lambda readings. trims on mine are around 12% i think on long term

I'm going to finish back together, as the top rad pipe and fan isn't on it at the moment, so I can leave it running longer, I'm hoping the black smoke is just the old stuff coming out the exhaust, it revs fine now as it seemed to be holding back throughout the rev range before. I'll check the plug leads because they do seem slightly dodgy fitment. I can get access to Snap on scanner, which should read the settings. It was spitting droplets of soot out when blipped to start with, it was only black smoke at fullish throttle.

Forgot to add it seems a bit knocky when idling

where about are you?

An ECM (Adaptions) reset would be a good place to start. After that reset idle and look at the MAF readings. Obviously you need an independant with TestBook or Autologic/Rovercom etc.
You don't say what year your car is? I have the Gems system on my Dads 1996 car and the Motronic on a 2000 car. The displayed info for each model is very different on TestBook.
Example: have just come in from running the diagnostics on the 2000 model as it was running a bit rough with a lumpy idle, seems one lamda is not working as it should. Changed both, did another Adaptive reset and she is sweet again. The car is just too complicated to do a fueling fix without the diagnostic kit to point out the problem.

Message to the Forum gods: please have a list of all available TestBooks/Rovacoms and Autologic guys with location and phone numbers.

I'm in Walsall the West Midlands Gav.
It's a 1995 4.0 42d engine code running coil packs. My mates scanner is the top of the range Snap On one, I've seen it read live data on other cars, and he also bought the key for the scanner especially to read my Range Rover, he's already plugged into it before and it came up with faults for things I knew about, that I had unplugged. I think the only thing it can't read is the ABS and SRS system. Luckily it will reset the suspension system aswell. What is Testbook all about? And does that mean there's a choice of two different computers for each ecu?

stopover said:

Message to the Forum gods: please have a list of all available TestBooks/Rovacoms and Autologic guys with location and phone numbers.

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or at least a place where they can add thier details if they are not a buisness!!! and recomendations only, no slagging off!!!

mattfletcher said:

I'm in Walsall the West Midlands Gav.
It's a 1995 4.0 42d engine code running coil packs. My mates scanner is the top of the range Snap On one, I've seen it read live data on other cars, and he also bought the key for the scanner especially to read my Range Rover, he's already plugged into it before and it came up with faults for things I knew about, that I had unplugged. I think the only thing it can't read is the ABS and SRS system. Luckily it will reset the suspension system aswell. What is Testbook all about? And does that mean there's a choice of two different computers for each ecu?

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the rovacom (i think) can set up security stuff, reset becm and engine ecu links for immobiliser and generally everything else. its the stuff used by the main dealers.

i think the otherstuff is more aftermarket with less ability.

the engine ecu can be read by any compatible box/software/diag machine using the iso9141-2 protocol, wich is pretty much the same as rs232 but slightly different voltage on the uart line.

the engine ecu reading is in itself not a complete package but the one i have cost me 30 or 40 quid and is valuable in that it will help fix engine stuff like the fault codes stored. i get these alot with gas, although they dont affect the car i like to keep em cleared every now and then just to save it doing something silly!!!

Right I put it all back together, had it running for 15 mins+ no overheating at that stage, it was just sitting just under half way and creeping back up to half and back down again. Heaters weren,t very warm, but obviously I'm going to put it down to air locks in the cooling system at this stage. But it's still struggling to rev when warm, wouldnt rev very easy past 1500rpm, was then idling up and down below 500rpm, but not cutting out. Any suggestions? Could it be a temp sensor?

get it on the diag and see whats what, your really stabbing in the dark. the temp should be around 89 degs when running at normal temp!