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Discussion Starter #1
I have a problem with both my rr p38's now i have a 94 4.0l and a 95 4.6 hse
Both have a tendantsy to flood up and will not start however long you crank them over .only remady is to remove 8 plugs heat them up burn out the fuel in the cylinders refit plugs and sometimes it will go as normal sometimes it will flood up again. Has good spark (1.5 inches) while cranking new fuel good battery new coils plugs leads temp sensor maff when it does start it runs well but next morning back to square 1
run out of ideas now someone must have a clue to this problem
 

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Is the fuel pressure return hose blocked? Or, as it is affecting two cars, is there anything you've done that may have caused it?
 

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Discussion Starter #4
If i had done something i could onderstand it but one died 2 months ago oyher one died this week
Fuel pressure is 40 and 38 second one died following running out of petrol but cant see the connection as has run since
 

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How long since you've reset adaptive settings? stft will go to +38 % when cold, and I suppose if you have a v high learned ltft that may cause excessive fuel.
My 4.0 will start on the nose, but if it doesn't catch first time (generally if I turn the key back too quickly) it also won't start ie that first crank does seem fairly crucial , second time around there's too much fuel
As Richard says, the fact that it's both... have you done anything to both - any additives perhaps, or adjustments to the IACV?
I was wondering if you might have leaky injectors, I had an issue hot starting on my 4.6 which disappeared once I had the injectors professionally cleaned. but it was absolutely fine starting from cold... Does your fuel rail hold pressure overnight?
 

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Maybe compare the fuel pressures after you come home of an evening, to what it says in the morning. I'm not sure if those pressures are "healthy" or a bit too high, they're higher than mine, at least... Perhaps the injectors cannot hold the pressure and/ or the regulator is not releasing. I'd also be tempted to send off one set of injectors for cleaning and see what happens - resetting adaptive values is probably the quick win
 

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Take the vacuum hose off the FPR...do you have fuel in there?
 

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Discussion Starter #8
I have never reset the stft whatever that is or used any additives had the 4.0 l 4 years with only a o2 sensor needing changing for mot when mixture went high on lh bank hse not done anything to it in 3 years
4.0 drops fuel pressure in 30 seconds so i suspect an injector as when it will run it has an intermittant missfire on 1 cylinder not checked 4.6 yet
You mar be right in your thoughts but i cant see all the injectors failing at the same time on 2 cars
How do you reset the stft ?
Take the vacuum hose off the FPR...do you have fuel in there?
No fuel in fpr on either
 

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have you replaced the plugs or any off the coils . what type of fuel are you using have you changed the fuel suppler . 38 psi fuel pressure is excellent pressure. very strange that two vehicles have done the same thing . to eliminate one cause try another fuel suppier ?
 

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The fuel pressure shd definitely not drop in 30 seconds. I agree it seems unlikely that all injectors are leaky, but if there's been a pressure increase on the rail then that could have given rise to an issue across all cylinders.
To reset the trims you need some kind of diagnostics eg Nanocom, where are you based?
You could also try this app, I tried it once out of curiosity but cdnt get it to work and just used my nano, supposedly you can reset adaptive values in there

GEMS ECU Utility for Land Rover - Apps on Google Play
 

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Discussion Starter #11
have you replaced the plugs or any off the coils . what type of fuel are you using have you changed the fuel suppler . 38 psi fuel pressure is excellent pressure. very strange that two vehicles have done the same thing . to eliminate one cause try another fuel suppier ?
Both had new fuel last d days from different places
4.0 has had coils leads plugs cps maff tps temp sensor pump relay +fuse still same
The fuel pressure shd definitely not drop in 30 seconds. I agree it seems unlikely that all injectors are leaky, but if there's been a pressure increase on the rail then that could have given rise to an issue across all cylinders.
To reset the trims you need some kind of diagnostics eg Nanocom, where are you based?
You could also try this app, I tried it once out of curiosity but cdnt get it to work and just used my nano, supposedly you can reset adaptive values in there

GEMS ECU Utility for Land Rover - Apps on Google Play
Im near canterbury u.k.
i have a modis but it doesnt show any problem when it runs
The fuel pressure shd definitely not drop in 30 seconds. I agree it seems unlikely that all injectors are leaky, but if there's been a pressure increase on the rail then that could have given rise to an issue across all cylinders.
To reset the trims you need some kind of diagnostics eg Nanocom, where are you based?
You could also try this app, I tried it once out of curiosity but cdnt get it to work and just used my nano, supposedly you can reset adaptive values in there

GEMS ECU Utility for Land Rover - Apps on Google Play
Ill try that app tomorrow thanks
 

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you need 3 things for it to go air, fuel and spark
if the spark is an inch long its good , air, outside of a rag in the intake you would have air and the fact that it dose go eliminates that . you are left with fuel. if the plugs are drenched in fuel then you have fuel. back to the spark, you need to get a timing light and make sure that the spark is there when you start cranking. put the pickup for the timing light directly on the coil pack and see if it has spark when you crank the unit over. its a process of elimination (dose this happen in all places or only in the driveway)
 

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Discussion Starter #13
you need 3 things for it to go air, fuel and spark
if the spark is an inch long its good , air, outside of a rag in the intake you would have air and the fact that it dose go eliminates that . you are left with fuel. if the plugs are drenched in fuel then you have fuel. back to the spark, you need to get a timing light and make sure that the spark is there when you start cranking. put the pickup for the timing light directly on the coil pack and see if it has spark when you crank the unit over. its a process of elimination (dose this happen in all places or only in the driveway)
it happens anywhere and the spark is 1 inch long when cranking both are un different locations atm neither will start
 

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The last thread I read where a guy had run out of fuel and then replaced a shopping list of items in order to get the RR to start again ended up rolling back most of the replacements and then found he had been supplied the incorrect TPS. How sure are you on all the quality of all those sensors you changed? esp MAF, both of mine will not start or only just start if i disconnect the MAF. Laser tools do a set of xmas lights for the spark plugs for c £10 - may help you eliminate the sparks as an issue
Canterbury is a bit far from Twickenham, but there may be others closer.
 

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dose it have spark when it dose this ? the reason i ask is their is many things that turn off the spark. but you still have the common denominator , the pair off them doing the same thing
PS my thinking is it may have been a signal from some dodgy house alarm interfering with it , but if in different places then maybe not. there has to be something associated to both vehicles.
 

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Discussion Starter #16
Well thats a good point but when it does run it will start with the tps disconnected but not rev wel and if the maff is no good it will not go at all which it sometimes will in all it does not make sence why it is doing it
dose it have spark when it dose this ? the reason i ask is their is many things that turn off the spark. but you still have the common denominator , the pair off them doing the same thing
PS my thinking is it may have been a signal from some dodgy house alarm interfering with it , but if in different places then maybe not. there has to be something associated to both vehicles.
yes a very good spark
 

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How did you get on with the app? Needs diagnostics before running in any more circles. The fact that this is two cars may just be an unfortunate coincidence . You should have a tps idle reading of around 0.6V +/-.02V. The MAF should be around 1.3V+/- .1V at warm idle. IACV shd be about 22 steps +/- 7. Or at least they are on my '98s. This will tell us if one of the components is dodgy. You can also try swapping the old MAFs between cars, they should be the same part number. But if you have all this new stuff, and have not done an adaptive reset, or done enough miles for the car to re-learn anything, then the ECM is still stuck on its old settings.

BTW, I think the running out of fuel could be significant because you may have dredged up some cr** from the tank and now the injectors have been compromised
 

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sorry without more diagnosis i am out of ideas . as romanrob says you need to check those parameters . maybe new plugs or something in the one that didn't get anything done to it . i do know that plugs today don't like being drowned in fuel it tends to kill them even new ones . i have also had other vehicles stop because of poor plugs for no apparent reason , they just will not start. yes we are scratching the bottom off the barrel without diagnosis
 
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