Fuel Starvation? Coolant Loss...

[Davenotouring]

The 2.5 is in...I expected one or two teething problems, here they are!:

1) When I boot it in first it shifts then dies then shifts again, like kangarooing.....Is the 2.0 fuel pump different to the 2.5 one? Is not enough fuel getting through?
Or should I be looking at more obvious things, like bent pipes etc?

2) It uses a bit of coolant, not a substantial amount but some.
Now, it doesn't overheat, it doesn't smoke.....I have looked for leaks but can't find any I'll have a proper look, but does anyone have any bright ideas about this?!

Bar these annoying problems, I'm loving it!!

[Andy335Touring]

Fuel pump should be fine mate,my 3.5ltr is run by the old 2.5ltr pump with N/P's.

I think some one said they had a similar problem to yours that they cured by moving the arm in the AFM to an unworn track or some thing similar ?

When it's working try this link.

http://frwilk.com/944dme

Trouble with these slight miss fire/running prob's it could be lots of things so finding what it is can be tricky.

Not sure about your leak but an over looked place to check for leaks is where the heater pipes connect to the heater matrix on the bulk head.How much is it using ?

[Toby_Unna]

coolant's likely to be a rubber hose not clamped properly or split. had this problem when i put the m30 in and was worried but it was just that.

a 316i pump will run a 220bhp m30 3.5 fine, which utterly utterly drinks fuel if that helps!

a fueling problem like that would be more prominent in higher gears, you can't be in first on full throttle for very long like you can in 5th!!!

bad earth connection somewhere, possibly alternator (i had that problem too), fuel pressure regulator (unlikely but you can swap the 2.0 one on to check...)

[Davenotouring]

I'll have a better look over it tomorrow, just seems to happen in first....and the tank isn't near empty. Feels like the fuel goes to the back of the tank then back so it moves, then flows to the back it dies etc etc.

Oh well. Only happens in first, the rest of the time it's fine.

Coolant.....I'll check all the pipes over, but I can't see any leaks or wetness in the bay or on the hoses. Hmmmm.

[Toby_Unna]

well it ain't going to be a serious problem if it only does it in first gear i reckon.

mine was doing that all the time when the alt went screwy.

[Davenotouring]

Luckily I have a spare alternator if need be. Hmm, I'll check all the earths and so on tomorrow for that problem, very annoying when I want to make a quick getaway!!

Obviously everything was undone, so I'll check it over tomorrow.

[gareth]

i had similar problems a while ago. turned out to be a pin hole in the top hose, squirting steam all over/inside the distributor cap!

[Demlotcrew]

I'll have a better look over it tomorrow, just seems to happen in first....and the tank isn't near empty. Feels like the fuel goes to the back of the tank then back so it moves, then flows to the back it dies etc etc.

Oh well. Only happens in first, the rest of the time it's fine.

Coolant.....I'll check all the pipes over, but I can't see any leaks or wetness in the bay or on the hoses. Hmmmm.

The pump sits in a bucket in the tank to stop this.

Andrew

[Davenotouring]

Andrew, I guessed that was the case, it's just that that is how it 'feels'!

[Davenotouring]

The N/S engine mount is snapped.....I noticed while having a look around under the bonnet?

Could this have anything to do with it?

If not, and I can't cure this by next week, I'll take it to the specialists.

This is really annoying now!!!

[Demlotcrew]

What the new one?

Im not sure if the engine is even in the right possition, check that all the mounts are in the correct holes. (small holes are correct)

Andrew

[Davenotouring]

The 'new' mount was on the other side. This was an old one, which wasn't broken, but is now.

I'll have another look, but my trolley jack and stuff is in Cambridge.

I will probably drop it into the specialists next week for them to have a look.

Is it a bad idea to run the car with the AFM disconnected to rule it out?

[Davenotouring]

I just drove it with the AFM disconnected.....

It runs perfectly on WOT and slight throttle, and dead everywhere else.

Does this mean the AFM is at fault, or does having the AFM dissconnected put it in limp home mode?

Cos it's solved the jumping on full throttle when it's disconnected....??

Help!!

[Demlotcrew]

The ecu doesnt take any signals from the AFM when the TPS is on wot.
Thats why i say a custome remap is needed after you git a BOTB

Andrew

[Davenotouring]

Ahhh, ok.

But this could mean the AFM is bust.

Also, just noticed there is a slit half way round the rubber inlet pipe.....Does this help?

[Demlotcrew]

thats the problem mate, not the AFM as you boot it the engine moves and the gap lets air in. On the M42 there are metal spacers inside the boot to stop it compressing when changing gear which helps with instant power delivery

you could do the same with a new boot.

Andrew

[Davenotouring]

So lots more air is going in than the ECU thinks.....

And the Engine mount is just making matters worse.....???

[Demlotcrew]

yup

[Jesus325iTouring]

ecu AFM TPS wot.
BOTB

Andrew

I was readin this thread with interest untill I got here..............

[Davenotouring]

ecu = engine (electronic control unit)
AFM = Air Flow Meter
TPS = Throttle Position Switch
wot = wide open throttle
BOTB = Big Bore Throttle Body (should be BBTB I think!)

Hope that helps!

[Jesus325iTouring]

ecu = engine (electronic control unit)
AFM = Air Flow Meter
TPS = Throttle Position Switch
wot = wide open throttle
BOTB = Big Bore Throttle Body (should be BBTB I think!)

Hope that helps!

Cheers Dave,thread now makes sense!

[Demlotcrew]

Bored Out Throttle body.

[Davenotouring]

Bored Out Throttle body.

Ahhhhh.

Same thing really

[Demlotcrew]

:yeahthat: