WTBorrow: M40 sparkplugs - chch!

[Linden 0]

Hey guys, im just wanting to test another set of plugs in my 318 before i buy a new set..

Reason being my car is rev limiting at 4k and i cant figure out why, so far ive tried: new leads, different rotor cap, different coil, different computer and its still limiting at 4k, last test is sparkplugs but i wanna see if thats the problem before i go buy a new set...

cheers

Linden

[Forrest 35]

I have four essentially brand new ones, if you want to pay for postage I can send em down if you have no luck closer

[antil33t 90]

This may sound silly... but is your throttle cable pulling all the way?

get someone to watch your tach, as you manually open the throttle?

[*Glenn* 854]

From your description ... I'd say blocked exhaust, AFM, fuel filter blocked or fuel pump

[brockie123 31]

Hey Linden, Reckon I have a set of plugs that I am pretty sure are for a M40 318, (best check first though) they are brand new - Champion N9YC you are welcome to try them. give us a yell on 027 4576909

I did a quick google check and could find nothing to show if they were correct or not.

[hotwire 352]

I suspect possibe causes as Glenn has suggested & doubt it's plugs.

Surely though - if you want to eliminate plugs then simply buying & fitting a new set is hardly an over the top cost to incur

[OP6 27]

Perhaps the timing is out. Has this problem just started?

[Linden 0]

I suspect possibe causes as Glenn has suggested & doubt it's plugs.

Surely though - if you want to eliminate plugs then simply buying & fitting a new set is hardly an over the top cost to incur

I dont want to spend money i dont need to as I have little supply at the moment lol

From your description ... I'd say blocked exhaust, AFM, fuel filter blocked or fuel pump

whats the easiest way to check these?

Hey Linden, Reckon I have a set of plugs that I am pretty sure are for a M40 318, (best check first though) they are brand new - Champion N9YC you are welcome to try them. give us a yell on 027 4576909

I did a quick google check and could find nothing to show if they were correct or not.

Sweet, I will pull out the plugs in mine and check the code on them.

Perhaps the timing is out. Has this problem just started?

Has done it since I bought the car not long ago, it revs nice and smooth untill it hits just over 4k rpm then it seems as though it hits a limiter and just bounces.

[rxsumo 33]

I'd be listening to Glenn's advice....

My M30 528 has a similar problem...which I reckon is the AFM....but as its only a parts car it isnt worth investigating,

To check the exhaust.....break the exhaust at the first joint....manifold to front pipe.....fire up the motor and see if it will rev out.....if it does- you will need to go down the exhaust breaking it at the various joints to determine what section is blocked.

As for the fueling components - an external fuel pressure gauge for testing might be a good start, and check whether the pressure is within factory tolerances and see if it falls off as the revs come up

[brockie123 31]

i have heard of this problem before. i'd agree with op6 here sounds like the timing.

[Linden 0]

Its starting to frustrate me so i went and got some brand new plugs yesterday and chucked them in with no success, the old ones were all yellow and running too hot so i got some colder ones anyway.

I also tested it with a second AFM and no success..

I will have to check the timing and exhaust now.

The engine revs nice and smoothly straught up to 4k and hits a wall so i have my doubts about it being fuel as it is so consistant

[brockie123 31]

i am 95% sure it is the timing. get it done anyway it's cheap as.. you could probably do it yourself?

[edit]

when you drive it flat foot it stops at 4k? what happens if you are driving it and it gets to where it is limiting itself and really slightly have your foot on the accelerator but enough to speed up does it go past 4k even just a bit?

Edited August 11, 2009 by brockie123

[c.robertson00 11]

If your car is a facelift 318i then it could possibly be a worn cam? Someone will correct me if im wrong.

[Linden 0]

i am 95% sure it is the timing. get it done anyway it's cheap as.. you could probably do it yourself?

[edit]

when you drive it flat foot it stops at 4k? what happens if you are driving it and it gets to where it is limiting itself and really slightly have your foot on the accelerator but enough to speed up does it go past 4k even just a bit?

cant get it past 4k, it feels like its actually limited there if you're driving it and plant boot it changes down and just uses revs below 4k like it was built to have 4k limit if you get me..

If your car is a facelift 318i then it could possibly be a worn cam? Someone will correct me if im wrong.

Yep its a FL 318i - M40 engine, should i expect a worn cam in it at 132kms though???

[Deano 1]

cant get it past 4k, it feels like its actually limited there if you're driving it and plant boot it changes down and just uses revs below 4k like it was built to have 4k limit if you get me..

Yep its a FL 318i - M40 engine, should i expect a worn cam in it at 132kms though???

If its motronic its non adjustable timing..except by the belt or chain so look else where first.

Check the throttle is fully opening by looking into the throttle body and if thats OK then swap in another ECU.

[Linden 0]

If its motronic its non adjustable timing..except by the belt or chain so look else where first.

Check the throttle is fully opening by looking into the throttle body and if thats OK then swap in another ECU.

Alright ill check the throttle body today im not sure if it'll be this though as when it hits 4k it has that limiting sound unlike the smooth sound of holding the throttle open at say 3.5k for example,

I have already swapped in another ECU with no success.