1986 325i engine rebuild and motronic upgrade to 1.3

[Avinit4]

Thanks Grrrmachine..... Excuse my ignorance as I'm not to good with the obvious but what is FPR?
What way do the wire clips on plugs need to go: away from the Head or towards it? I cant tell because there flush all way round the plugs?
I just need to somehow get some leverage on number 3 injector to push it in properly as opposed to removing them all with the fuel rail!

[Grrrmachine]

FPR is Fuel Pressure Regulator, at the end of the fuel rail.

You'll need to get the rail off because you don't know whether the injector is just not pressed in enough or, more likely, the rubber gasket ring got twisted when fitting, leading to an imperfect seal.

[Avinit4]

OK kool, thanks again Grrrmachine.

I've just got the injector loom out and defo not looking forward to putting it back in...lol

The rubber ring getting twisted when fitting sounds more likely to me so now the rail and hope I fit it right this time, I'm thinking a little bit of vasilene might help this time.. ... Thanks again, much appreciated.

[Avinit4]

Thats sorted Now a running problem Seems like this will never end altho I know im close now surely?
She starts up but wont rev up, infact when I hold throttle little bit down the engine revs then drops away juddering then revs and drops away judering again. Ive video'd it so you can actually see/hear it for yourselfs as will make more sense then I hope?



As always your help is much appreciated because I havent the faintist idea other than I must be close to actually completing this mission

[Grrrmachine]

It's either an air leak (most likely) or a poorly set up/broken Throttle Position Switch (likely) or a disconnected/broken Air Flow Meter (unlikely).

That gives you some avenues to pursue.

[Avinit4]

Nice one... I'l start reading up on those now....Cheers

[Avinit4]

Yep, it as an air leak,...... But she idles and revs up a bit and then dies/comes back dies/comes back ..... its easier to hear what I mean in this vid... I'm thinkin its something else now because the air leak has been sorted.
The Throtle Position switch worked fine before rebuild & Motronic upgrade but if you think thats still a possibilty I'l take it off and give it a clean?



I noticed when it dies the fuel light flashes at the same time?

[Grrrmachine]

A very simple thing; did you do the ECU warm-up procedure? When fitting a new ECU, or one that's been disconnected for a few days, you need to let the car idle for ten minutes to warm up, then turn off, turn on again and take it for a howling blat around the lanes for ten minutes. That way the ECU learns its settings based on its map.

If you haven't done that then the engine will be running lumpy. To reset the ECU, just undo the two battery cables and join them together for a few minutes.

[Avinit4]

I pressume you watched the 2nd vid so what you heard falls within your defintion of running lumpy?

I wasn't aware of the ECU warm up procedure so obviously didn't do it! I wont be able to this procedure for about a week because I still need to redye the leather seats before refitting, plus few other bits before I can drive it. But once I've done it I'l let you know the outcome.

Due to fact I need to run the engine in I can't do a howling blat around the lanes for 10 minutes so would you recommend I do the ECU warm up procedure again after I have run engine in. I ask because its only after I've run her in that I can do the howling blat part of the procedure.

Finally I can see the light at the end of the tunnel so Thanks sooooooooo much Grrrmachine and everyone else thats helped me

[Speedtouch]

Yes, carry out the ECU initialisation procedure regardless of how you then drive it thereafter.

This enables base idle settings to be learnt.

[Avinit4]

Is it important to drive the car after ECU initialisation?

I ask because I just followed the initialisation procedure thinking I would be able to rev it up after (cant drive it for reasons stated above). However, although it sound much smoother on low revs, when I increase revs it returns to goin up and down on its own (like in the vid).

I was about to repeat the ECU initialisation when I thought perhaps driving the car immediately after (as opposed to reving her up) is a nessercary part of the process?

Sorry if this is a stupid question but thought best to ask before repeating procedure

[Speedtouch]

Well, if you want the ECU to learn the full settings, it is necessary to drive it under load conditions, throughout the rev range, having followed the idle initialisation procedure.

[Avinit4]

OK I'l get the other bits done asap then repeat ECU intialisation procedure then take for a drive , will post the outcome....Thanks again

[Avinit4]

After colonising seats etc I finally make it back to the engine ecu initialisation procedure.
1st attempt..... discovered small fuel leak in fuel pipe so renewed and restarted ecu initialisation procedure

2nd attempt..... Engine started on the key and idled beautifully for 10 minutes. I then turned off and restarted for the 10 minute drive. NOTE: because previously the engine would not rev up after the 10 minute idling procedure and I was advised I needed to do the 10 minute drive I made sure I did not rev it before pulling away incase this affected initialisation procedure.

With in 300 yards the engine was the same as in the video shown above so couldn't even pull away from the roundabout I was now stuck on. I undone batery, joined conectors together for 20 seconds to clear ecu and repeated ecu idling initialisation procedure. Altho this time wasnt as smooth and afterwards car couldn't pull away becos wouldn't rev up enough so needed to get towed home which brings me to writing this.... I'm gutted she's not running and desperate to overcome this issue so your input guys will be pricely...Cheers

[Grrrmachine]

It's either an air leak (most likely) or a poorly set up/broken Throttle Position Switch (likely) or a disconnected/broken Air Flow Meter (unlikely).

You say you've cured an air leak. So follow the other two avenues.

[Avinit4]

Ok thanks Grrrmachine, youve given some idea/context of where I'm at because my brains completely frazzled with untold info from last 8 months on this.

I'l go back to start wiv the air leaks and redo them just incase because I'm seriously doubting the throttle position switch (thats bit scewed on bottom of throttle housing yes) because I've had car over 10 yrs and it was spot on prior to engine rebuild and motronic upgrade so I'm not quite understanding what could have now caused it to malfunction? But I will do that after checking air leaks.
Altho I need to lfind a guide to ensure I do it right so about to look threw ones on here...Cheers

[Avinit4]

Grrrmachine...... I havent a clue where or how...... * I tried to use text speak but the text speak filter stopped me * that sentence came from........ I defo never wrote it so please ignore it.

[Grrrmachine]

That message pops up if you type like a spaz. So don't type like a spaz and it should be alright.

With the TPS, considering you have do take the old engine loom out and refit a new one there's a high chance you disturbed the TPS, since it sits right on top of the loom as it passes under the intake manifold. If the TPS was unplugged or unseated then the engine will have no clue that you're pressing the accelerator, and won't know how to interpret the sudden increase of air entering the engine - potentially causing your "hunting" problem.

[Avinit4]

....lol.... kool...Cheers

[Avinit4]

OK..... I've cleaned TPS (that had lots of oil in it) and I also replaced hose from rocker cover to throtle housing. Plus I checked AFM conected & working.

Result: No difference!

I know thought problem must be linked to the coolant temparature sensor so checked it and discovered this:
The Brown conection plug on Sensor contains 1 conection pin, but the brown conection plug on my new Motronic 1.3 engine loom contains 2 conections.
I checked my old motronic 1.0 engine loom and the brown conection plug only contained 1 conection.
So now i'm thinking the ecu is expecting to recieve data threw its 2 conections in the brown plug but is only recieving data threw 1 because my original sensor only contains 1 pin conection.

Solution: Source and obtain coolant temparature sensor with brown conecting plug containing 2 pin connections (not easily achieved without car registration number, which I dont have because engine loom came from a 1990 e30 325i)

Does this make sense to anyone and am I right to conclude what I have?

[Grrrmachine]

Ignore the Brown plug, it's got nothing to do with the ECU or any other engine data. It exclusively supplies the dash cluster.

[Avinit4]

Only read your reply Grrrmachine after I'd already got another sensor, although its only the e36 temparature sensor that has the 2 pin connection. Wich begs the question has someone previously adapted an e36 injector engine loom to fit an e30 that has been sold to me as an e30 injector loom? Could this cause problems?

Anyway I fitted the e36 temparature sensor but again made no difference except after reving up and enging was hunting a loud intemitent buzzing noise came from the middle of the injector loom trunking? Only stoped when battery disconected?

I have now took the AFM off and apart to clean inside but wasn't very dirty and about to replace it and try again. Altho I doubt will make any difference.

Could it be the ecu itself malfuctioning, after all it is 2nd hand off of ebay?
I'm sooo fu**ked off with this its unreal and I sooooo wish I left the original motronic 1.0 on it now!!!!

[Avinit4]

So...... I rechecked for air leaks several times and to be sure I renewed any pipes that looked old.

Ive cleaned out the TPS and I've replaced it with another I had.

Lastly I took the AFM apart cleaned and replaced.

Result: Engine still Hunting..... If anything its slightly worse?????

This may be of significance..... The rev ometer doesnt work and when the engine hunts the fuel light flickers?

Personally I'm wishing I set fire to it instead of restoring it cos its putting me on a perminant downer, especially now Ive exhusted the normal avenues for this issue..bla bla...

[Speedtouch]

I have a spare 0 261 200 173 available if required, with the chip of your choice fitted - standard, Mild or Wild.

[Morat]

How are you checking for air leaks? Visual inspection? It might be worth wafting an unlit blowtorch near the pipes you're checking to see if the engine surges due to sucking in gas. In moderation, don't be creating a bomb under your bonnet!!

[Avinit4]

Ive checked for air leaks by just looking & renewing to be sure, but I will do the unlit blow torch test to confirm or dispell air leaks, thanks morat.

Speedtouch, assuming theres no airleaks, yes mate I'm definitely up for your spare 173 ecu with the mild chip (wild chip only better with other modifications yes?).

What sort of money are we talking (can PM me answer pls) and if for some reason it turns out not to be ecu problem so makes no difference can I return it? If thats poss and you dont ask silly money then I'l do that for sure.

Okey dokey I need to get hold of a blowtorch to check fo leaks before anything else.... Thanks people for giving me some hope this will soon be overcome

[Avinit4]

Have done blow torch test and couldn't find any leaks so I'd say its safe to rule out air leak as possible cause, thanks again morat for that method.
Speedtouch I'l PM you my number if easier to talk... Cheers

[Speedtouch]

PM sent!

[Avinit4]

Have returned PM and sorted paypal stuff...cheers

[Speedtouch]

PM replied to.

Thanks,

[Avinit4]

Okey Dokey..... Sadly the ecu didn't solve the problem but finally think I have sussed it.

While the enging was idling (but hunting still) I removed the Idle Control valve plug and to my amazement the hunting stoped. Whats more is when I held the engine at higher revs it stayed there instead of starting to rev up and down on its own, which has been the main issue.

So I need to acquire another Idle control valve but its saterday evening now so will have to wait till next week, which brings me to these questions:

Is it ok to drive the car with the idle control valve is unpluged? (I really dont want to be towed home again!)
What is consequence of having it unpluged? Thankyou people I'm almost there and I'm hoping someone will be able to tell me if I can drive the car now?

[Grrrmachine]

I think you're confusing the symptom with the cause.

If the ICV ran perfectly up till the Motronic swap, then it's very unlikely to have suddenly failed. Far more likely is that the engine isn't being told when to idle and when not, and that's the fault of the TPS - a far more suspect culprit.

Daft as it sounds, when you swapped the engine loom are you sure you got the right plug to the TPS?

[Avinit4]

Your a clever fella Grrrmachine.
Because the plugs look the same I couldn't be sure I had the right plug to the TPS so I just swoped over the ICV & TPS plugs. Result: revs OK now, she's not perfect but thats probably to do with the little screw on the throtle housing I was turning earlier to see if it made a difference, culminating with me not knowing where it was to start with opps!

So she's idling and reving now wth both plugs on so obviously must have been wrong way round.

Prior to reading your message Grrrmachine I tested the Ohms on ICV and 2 outer pins were 43 Ohms and center to outer were 21 and 23 Ohms, which I believe means ICV is OK.

Well I need to refit seat and see if she's drives OK. I'l post the outcome. Many thanks

[Grrrmachine]

I'm not that clever - should have thought of it before you got sent on a wild goose chase chasing the AFM and whatnot.

Hope it all works out for you. Don't forget to reset that screw, otherwise the car won't know when to idle. With the cable set to the right tension, you should hear the AFM click as soon as the throttle arm is moved off its stop - that screw IS the stop, so adjust it until it's set up like that.

[Speedtouch]

Good to hear you now have it running pretty well.