Getting anoying now!

Hey guys!

The rangy is still running like a bag of crap .....

At first i put it down to a failing fuel pump. I just swapped it (Through the boot method ) but my problems are still there!

Its a 4.0v8. The symptoms are, Wanting to cut out at idle (sometimes it does cut out) always when im at a junction/traffic lights!

It idles fine when in Neutral or Park, but when i select D the revs drop straight down (Sometimes to 0 revs nearly stalling)

When i go to accelerate the revs drop for a couple of seconds then pick straight up.

I changed the O2 sensors about 5 months ago, I changed the coolant temp sensor a few months ago too.

Also whilst its running rough it smells very Rich, with smoke noticably coming out the exhaust!

Any ideas will be much appreciated

Scott

color of smoke,

possibly MAF
Ecu Temp Sensor another possibly-rave should have test values

fanatic said:

color of smoke,

possibly MAF
Ecu Temp Sensor another possibly-rave should have test values

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The smoke has a bluey tinge to it, but when its not not running rough (Before i select D) theres no smoke?

MAF.. get it running then disconect the MAF plug it shoud settle down and run properly.
You can go for a drive with it disconnected and all your problems shoukd be solved.
It will not start with the MAF disconnected so be aware if you go for drive.

lowfat said:

MAF.. get it running then disconect the MAF plug it shoud settle down and run properly.
You can go for a drive with it disconnected and all your problems shoukd be solved.
It will not start with the MAF disconnected so be aware if you go for drive.

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Thanks mate I'll give that a go and I'll let youknow what happens! Itl will have to be tomorra now tho cos the wife's gone out in it (properly cursing as we speak ha!) plus I'm just having a beer and don't want to get tangled up with the rozzers

If it is the MAF would I have to buy a OE One or is there a decent after Market version?

Cheers scott

I got one second hand from RPI they are on ebay.
Not sure how much from a dealer.

lowfat said:

I got one second hand from RPI they are on ebay.
Not sure how much from a dealer.

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Cheers bud, I'll post tomorrow as to how it goes

Scott

lowfat said:

MAF.. get it running then disconect the MAF plug it shoud settle down and run properly.
You can go for a drive with it disconnected and all your problems shoukd be solved.
It will not start with the MAF disconnected so be aware if you go for drive.

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Would this apply to a diesel as well?

Don't know only had experiance of the V8...

enery8 said:

Would this apply to a diesel as well?

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A dodgy MAF can cause all sorts of problems on a petrol engine, never had to replace one on a diesel but I would guess it could cause your problem The only easy way to be sure is to swap it for a known good one.

Datatek said:

A dodgy MAF can cause all sorts of problems on a petrol engine, never had to replace one on a diesel but I would guess it could cause your problem The only easy way to be sure is to swap it for a known good one.

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Morning Keith, Trouble is I dont have a known good one so looks like I will have to go to our local indy (they are not bad on price) Is there any way to check it with live data, do you know?
Just had the Hawkeye on it and it returned a 142 fault, start of injection. Cleared that but just the same. I have ordered the ect having blanked the egr and made no difference, if anything a little worse. Goes fine when at normal operating temp!
Oh well, keep trying!
cheers all for the help.

enery8 said:

Morning Keith, Trouble is I dont have a known good one so looks like I will have to go to our local indy (they are not bad on price) Is there any way to check it with live data, do you know?
Just had the Hawkeye on it and it returned a 142 fault, start of injection. Cleared that but just the same. I have ordered the ect having blanked the egr and made no difference, if anything a little worse. Goes fine when at normal operating temp!
Oh well, keep trying!
cheers all for the help.

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If you weren't so far away you could try mine MAF, temperature sensor, crank sensor, needle lift sensor are all possible causes.
Some things can't be seen via diagnostics, you need to use an oscilloscope to see an erratic output, at least that's what I do.

Datatek said:

If you weren't so far away you could try mine MAF, temperature sensor, crank sensor, needle lift sensor are all possible causes.
Some things can't be seen via diagnostics, you need to use an oscilloscope to see an erratic output, at least that's what I do.

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I have a scope (20mhz) and x10 probes. What else do I need? likely quite a lot
If the car was running okay I might just nip over and see you. Never mind, hoping to take the caravan to La Belle France next year, maybe then. Searching for my Mums ancestors around Rouen, then a bit of touring.

scott02464 said:

Thanks mate I'll give that a go and I'll let youknow what happens! Itl will have to be tomorra now tho cos the wife's gone out in it (properly cursing as we speak ha!) plus I'm just having a beer and don't want to get tangled up with the rozzers

If it is the MAF would I have to buy a OE One or is there a decent after Market version?

Cheers scott

Click to expand...

Not sure if yours is Gems or Thor but I've heard the aftermarket ones are crap. Mine came with an aftermarket one fitted and it had the same symptoms. Unfortunately genuine Gems ones are really expensive, Thor much less so.

Do the test to at least work out if you need one or not first.

Guy

kooky_guy said:

Not sure if yours is Gems or Thor but I've heard the aftermarket ones are crap. Mine came with an aftermarket one fitted and it had the same symptoms. Unfortunately genuine Gems ones are really expensive, Thor much less so.

Do the test to at least work out if you need one or not first.

Guy

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It's diesel At least I think enery8's is diesel.

enery8 said:

I have a scope (20mhz) and x10 probes. What else do I need? likely quite a lot
If the car was running okay I might just nip over and see you. Never mind, hoping to take the caravan to La Belle France next year, maybe then. Searching for my Mums ancestors around Rouen, then a bit of touring.

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Scope the outputs of the sensors and look for erratic waveforms.

Plenty of parking chez moi for a caravan, water, electricity and emptying available

kooky_guy said:

Not sure if yours is Gems or Thor but I've heard the aftermarket ones are crap. Mine came with an aftermarket one fitted and it had the same symptoms. Unfortunately genuine Gems ones are really expensive, Thor much less so.

Do the test to at least work out if you need one or not first.

Guy

Click to expand...

I know mate the OE ones for mine (4.0 Petrol Gems) are over a grand!!

Balls to that, its not an option LOL!

I did the test today and its deffo the MAF thats gone, It runs fine once disconneted.

I got an 'Allmakes' version ordered (£80). I know the after market ones have a bit of bad press but i cant afford an OE spec MAF, plus ill be running the risk that a second hand OE Maf could also not actually have that much life left in it....

Ill let you know how I get on with the replacment tho when i get it

Scott

Datatek said:

Scope the outputs of the sensors and look for erratic waveforms.

Plenty of parking chez moi for a caravan, water, electricity and emptying available

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Thanks Keith, I will get the scope out when/if the weather good enough (chucking it down at the moment) and check the outputs. Hopefully be able to get my otherwise beautiful P38 sorted out. I will let you know how I get on.

Looking forward to our trip to France next year with the 'van. Hope to see you then. I will bring Hawkeye so we can compare notes on diagnostic code readers.
All the best Bill

enery8 said:

.

Looking forward to our trip to France next year with the 'van. Hope to see you then. I will bring Hawkeye so we can compare notes on diagnostic code readers.
All the best Bill

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Look forward to meeting you

Datatek said:

Scope the outputs of the sensors and look for erratic waveforms.

Plenty of parking chez moi for a caravan, water, electricity and emptying available

Click to expand...

I have a semi portable 1mhz 'scope and wondered if that could be used, do you think that would be capable of checking waveforms? It is basically an audio spectrum 'scope.