E30 Zone

Hi everyone, I need some help with my rough running sport. Ive got a small vid to show what its doing. Its extremely lumpy, chugging a bit, alot of vibration and running really rich.



What Ive done so far.

Ive replaced the injectors for refurbed ones, off a M50 2.5. Was told from members in the know they will work fine but no power gains.

Ive replaced the plugs

Changed leads

Changed distributor cap for a better one I had

Cleaned up rotor arm

Changed the fuel pressure regulator 3 times

New main dealer TPS

About 4 AFM

All the intake pipes seem ok, have replaced a couple of them although a while ago now

It has had a replace blue sensor, but again a while ago now.

I ran a compression test. All the results are in PSI. No 1.165, No 2.145, No 3.155, No 4.140, No 5.140, No 6.135.

Im not sure what the compression should be but I did do a search and found on a thread someone had 180 PSI. I know mine is down some from that but would it result in the issues I have?

The engine has covered about 240,000 miles and I know its bound to be a bit tired and I have no problem replacing it but I dont want to go to all the work to find it still runs the same and I dont like to give up on something.

Other info that maybe of use. It hasnt had a oil change in an age

It has been driven hard in the 40k+ Ive owned it

Alternator is only putting out about 12.8. Tried about 3 different alternators one was fairly new but all the same about 12.8. So thinking theres a issue somewhere but was concerntrating on the engine running issue first but maybe there linked?

Car has been laid up (dry storage) for about 3 years now but it ran the same before I stopped using it.

If anyone could help it would be much appreciated. Thanks Jamie

I ould try gong back to standard injector personally. ecu map may not be matching etc...

Have you tried adjusting the tappets?

http://www.e30zone.net/e30zonewiki/inde ... M20_engine

Is it the motronic setup with a lambda sensor? If so try replacing that. I also have a set of blue injectors from a 1990 325i which i had serviced. No longer needed because i did an engine swap. You can also adjust the mixture on the AFM there's a screw toward the back of it. clockwise to richen anti-clockwise to lean it out.

I ould try gong back to standard injector personally. ecu map may not be matching etc...

I have thought about it. Only problem is the old set are definitly no good. Three of them were leaking fuel when not in use resulting in poor starting. Now it starts well but the running hasnt changed. I will try and track down some replacements, but Im not convinced it would cure the fault.

Have you tried adjusting the tappets?

Not for along time. I think that will be next on my list

Is it the motronic setup with a lambda sensor? If so try replacing that. I also have a set of blue injectors from a 1990 325i which i had serviced. No longer needed because i did an engine swap. You can also adjust the mixture on the AFM there's a screw toward the back of it. clockwise to richen anti-clockwise to lean it out.

No lambda sensor as far as I know. Its a 1991 but no cat. Also PM me what you would like for your set of injectors. Do you have the print out with them aswell? Im never keen to play with mixture screws but Im going to put that on the list after the tappet adjustment.

Thanks for the help so far guys its good to get other perspectives. Whatever the cause it is overfueling on all cylinders which made me think the injectors are ok or would I be wrong for thinking that? All the plugs are equally sooted up.

You could get your original injectors ultrasonically cleaned; there's a guy on here that does it:

http://www.e30zone.net/modules.php?name ... c&t=152878

have you checked the wiring socket under the inlet manifold?

I have checked the plug under the inlet manifold. Looks good on connector and under the rubber covers. Havent checked the tappets yet. But have decided next port of call is the AFM settings. After reading another thread Brianmoore mentioned about the Afm being adjusted to run better with badly performing injectors but now the injectors have been replaced it would need to be adjusted back. I think maybe this could also be my problem? My next question is, is there a default setting for the AFM? Somewhere I can start from as Im unsure where abouts its at. Ive never touched it personally but it could have been when its gone in for running issues in the past. Thanks guys

You really need to adjust the AFM with an exhaust gas analizer stuffed up it's bum...your local MoT man may well help you out at a quiet moment in his day.

Have you checked the inlet system for unmetered air leaks?

It's not uncommon for inlet manifold gaskets to suck in a bit and cause air leaks.

daimlerman wrote:You really need to adjust the AFM with an exhaust gas analizer stuffed up it's bum...your local MoT man may well help you out at a quiet moment in his day.

I know but in its present condition it has to be moved on the back of the truck or when it goes for test, which is an age off with other bits on the list to do. Was hoping someone may know where the screw starts its life. I will have a fiddle to she if i can get it better. I havent checked for unmetered air leaks since i replaced the injectors. Im going to go round it with an aerosol before i attempt any adjustments to the afm. Cheers for your help. Really hope to cure this soon. Havent driven it for over 3 years

Ive just been to the car. I sprayed hair spray around all the inlet while running. Nothing changed, so assuming i have no air leak. I couldnt get to the block end of the crank breather with the spray. So Im going to remove the inlet, see if anything stands out at me. Also going to borrow a inlet with injectors to see if that makes a difference. While thats off i will check the tappet clearance. Hopefully that will sort it if not Im really not sure what to look at next. Could it just be a worn engine?

Remove the plugs and see if they ends are all the same colour noting which cylinder each one is from.

jamie325isport wrote:Hi everyone, I need some help with my rough running sport. Ive got a small vid to show what its doing. Its extremely lumpy, chugging a bit, alot of vibration and running really rich.

Ive replaced the injectors for refurbed ones, off a M50 2.5. Was told from members in the know they will work fine but no power gains.

You state, 'the car is running really rich and I've fitted bigger injectors'

Kind of obvious isn't it?

I assume that you were advised that the injectors would fit, they will of course fit, but they will also inject more fuel refurbished injectors will be at their peak output rate as well making your stituation worse.

In it's current status your fuel management systems has no way of adjusting the fuelling because it is designed to run with known components which you have changed.

Adjusting the idle mixture won't help except at idle. If you want to continue with the bigger injectors the first thing you need to do is fit a lambda sensor, which your exhaust likely doesn't have a boss for. Unless your car has mechanical modifications that you would expect to see 20bhp from revert back to standard.

If your car is chipped, putting the standard chip back in will help a little, but will in no way resolve your problem.

Best of luck Alex.

A diesel knock so to speak but obviously petrol?

e301988325i wrote:

jamie325isport wrote:Hi everyone, I need some help with my rough running sport. Ive got a small vid to show what its doing. Its extremely lumpy, chugging a bit, alot of vibration and running really rich.

Ive replaced the injectors for refurbed ones, off a M50 2.5. Was told from members in the know they will work fine but no power gains.

You state, 'the car is running really rich and I've fitted bigger injectors'

Kind of obvious isn't it?

I assume that you were advised that the injectors would fit, they will of course fit, but they will also inject more fuel refurbished injectors will be at their peak output rate as well making your stituation worse.

In it's current status your fuel management systems has no way of adjusting the fuelling because it is designed to run with known components which you have changed.

Adjusting the idle mixture won't help except at idle. If you want to continue with the bigger injectors the first thing you need to do is fit a lambda sensor, which your exhaust likely doesn't have a boss for. Unless your car has mechanical modifications that you would expect to see 20bhp from revert back to standard.

If your car is chipped, putting the standard chip back in will help a little, but will in no way resolve your problem.

Best of luck Alex.

Car as far as I know is standard, Ive done nothing to the engine in the 8 or so years I have owned it. Injectors were fitted as they were known good working injectors. I did ask on another thread ( http://www.e30zone.net/modules.php?name ... highlight= ), was informed they would work fine but with no bhp gains. A good running car is all Im after.

Im going to borrow a inlet and injectors off a mate and go from there. If it turns out the M50 injectors are no good so be it. Learning curve.....

Try the breather pipe running from the crank cover to the inlet manifold. I found the jubilee clip was not done up tight and was casing it run like yours.

knightmare wrote:Try the breather pipe running from the crank cover to the inlet manifold. I found the jubilee clip was not done up tight and was casing it run like yours.

I will check it out. Is that the straight metal pipe from the block upto the inlet? Cheers.