Miss fire

[Billy the Kid]

Hi,
I am a newbie on the site. I recently bought a E34 540I 1994(according to the papers), in February I had to swap the motor with a secondhand unit and since then the car had a missfire, however from 3000RPM's the problem goes away.
I was thinking it might be coils (however I used the coils from my old motor because I did not get coils with the secondhand motor). I have replaced the plugs already with the specified Bosch replacement. Is there a way to test the coils maybe by measuring the resistance when cold as well as operating temprature? Also after I swapped the motor the car is extreamly heavy on fuel (3km/l).
Must the computerbox be remapped/programmed after the engine swap?

Any suggestions would be appreciated.

Thanks
William

 

[zaleonardz]

Welcome to the E34 540 club William...

The seem to have a cult status on here, and we have a few of them in the club.

As for your issue, the best would be to plug the car into diagnostics and pick up any error codes.

It could be coil, it could be injectors as well, but I am not convinced that its either of those, based on the fact that the problem goes away after 3000,

Your easiest and cheapest thing to do right now is run two bottles of decent injector cleaner through, and see if it solves the issue. 3km/l is stupid consumption, and a dead cylinder caused by either injector or coil will not take it to that level, so I suspect MAF or something like that.

Do you have any rocking at idle, ie car shaking ?


Your motor should not require it to be remapped, unless you replaced it with the M60B30, which is the 530 motor, but I dont think so...

 

[Billy the Kid]

Thanks for the welcome

I had a leaky injector seal about a week ago and replaced all of them over the weekend, I did take the time to clean the injectors with a bit of carb cleaner (do not know if it actually did anything good). I am going down to Bloemfontein this weekend so I will put some injector cleaner in and gun it down the higway a bit.

The motor is definitely a M60B40 as I made sure of this and also I was there when they pulled it out of the old car.

Is there a way that I can pull the codes myself or do u need special equipment for that, on my Telstar and MX6 I used to pull the codes myself.

 

[P1000]

Could be a MAF or vacuum leak related problem, but the high fuel consumption sounds like a injector stuck open... First step would be to figure out what cylinder is giving the problem if only one, then swap coil and injector one by one and see if the problem follows the part, then you have your defective part. Also make sure all the vacuum pipes are in the right place and not leaking. Oh, and the fact that it is fine at high RPM should indicate that it is not COIL related...

 

[clutchplate]

nah, if misfire under 3000rpm, thats most certainly your cam sensor, I am sure. vacuum leak you should only feel at idle really, unless its a BIG leak.
I have attached screenshots for you below of what your sensors reading should be, if you have a multi-meter you can check these items.. test your MAF and cam sensor and let us know how it goes..

here you go .. sorry for the big images, but I was lazy.

 

[brukutu]

Thanks for the welcome

I had a leaky injector seal about a week ago and replaced all of them over the weekend, I did take the time to clean the injectors with a bit of carb cleaner (do not know if it actually did anything good). I am going down to Bloemfontein this weekend so I will put some injector cleaner in and gun it down the higway a bit.

The motor is definitely a M60B40 as I made sure of this and also I was there when they pulled it out of the old car.

Is there a way that I can pull the codes myself or do u need special equipment for that, on my Telstar and MX6 I used to pull the codes myself.

I got a tool (obd2 reader) if you want i can maybe help you

 

[zaleonardz]

Just watch the E34 and OBDII, as not all systems are OBDII compatible, its a bit of a mixture, the ECU requires ADS to access it, but the airbag for example is OBDII.

Its very annoying isint it, as you cant do decent diagnostics

 

[Billy the Kid]

Hi,

Thanks to all for the advise - it seems as if I will have to get stuck under the bonnet soon, will start with the sensors and then check for leaks, the injectors was cleaned over the weekend.
Brukutu, I might take u up on your offer let me first check the other stuff and zaleonardz, I will keep it in mind that it might not be compatible.
Clutchplate, where do I locate the plug to test the MAF sensor's resistance and if you have Putty open on your desktop, what kind of work do you do?

:thumbsup:

 

[clutchplate]

cool man, yeah. that plug in the picture is for the DME .. just lift the black panel and disconnect the wire harness from the DME and you can test the pins directly..
work ? http://www.bmwfanatics.co.za/showthread.php?tid=7003&page=3
page 3, post #59. .. PuTTy just used for my unix boxes..
and since you actually know what PuTTy is.. what do you do ?, as I can obviously guess your in IT

 

[Billy the Kid]

Will do the tests over the weekend, thanks clutchplate.

Yeah I'm in IT, a Network Engineer(Cisco and Enterasys routing and switching).

William

 

[STREETRACER]

did you replace the engine with 100% the same as old engine? if not you are looking at a piggy back chip to set your fueling and timing accordingly!

 

[rick540]

Everybody's avoiding the dreaded Nikasil word......

Have you done a simple compression test yet?

 

[clutchplate]

cool beans Billy, will watch out for your post.. interested to see what it is..

 

[Billy the Kid]

Streetracer
Yes I replaced it with 100% origanal and also had to use most of my old sensors because the new motor was not 100% complete.

Thanks Rick540 I have thought of doing a comp test will do that as well and keep you guys posted.

William

 

[Billy the Kid]

Well I was suppose to pick up the F100 in Bloem on Saturday but the idiot selling the sold it on Friday. On Friday night I found another one on gumtree in Durban and we left for Durban early on Saturday morn and only came back late yesterday afternoon, hence the reason I could not do any of the checks over the weekend. However as I pulled out of Durban I realized the 540 had considerable less power than what she's suppose to have and just after PMB she started to backfire when I take my oot off the petrol, so my gues is burnt valves or something and I must do a compression test soon.

So I believe I found the cause of the missfire will confirm this with a comp test soon and keep u peeps posted.

 

[Billy the Kid]

Hi All.

I did say I will keep you posted as to what was wrong and yesterday I eventually got around to spending some time with the beast.

I did a compression test and found that cyl 4 is running on 650 and 6 is almost reaching 200 (Burned valves I think), so I started by removing the intake and exh manifolds to remove the heads.

I do have a spare set of heads waiting in the garage, I just need to send them to enginering for recons, so luckily the repair costs will not be to high.

If I can get enough courage to work in this cold weather I should be able to pull the heads tonight and get them back by Saturday morning and we should be up and running by the end of the weekend.

William

William

 

[Jandre]

Can't really decide if it is good news or bad news Billy. Guess it's good news, especially since you do have a spare set.

Let us know the outcome.

I dread the day I have to spend money on my 540's engine. Eish.

 

[clutchplate]

cool bananas billy ! its a pity about the compression :/ I was almost sure it would have been a cam sensor :/ I hope you come right man, take some pics for us

 

[Billy the Kid]

Well I guess it good news the only bad news is the amount of work and the fact that I dread the setting of the timing as I can remember the last ime I replaced headgaskets on my old mans 540 - I battled to get the cam timing sorted and I cannot remember the correct procedure no more.

Will see about the pics since my camera are in for a repairs - guess I can use the phone but it will be real sh!tty quality.

Cheers William

PS. anyone want some free booze while he gets his hands dirty, my girlfriend will keep our glasses filled hehehehe?

 

[Jandre]

By the way, as a matter of interest, what could one expect to pay for a second hand e34 540i motor?