e30 325i cutting out

[Etwenty1 45]

Getting E30 325i ready to sell and its playing up, i drive the car easy until it warms up but during mild acceleration it cuts out for half a second, like its not getting fuel? This car has had these parts replaced new over the last 6 months, Fuel pump, fuel filter, plugs, cap, rotor, valves adjusted. Strange but it only seems to do it just the once. Usually always when the engine temp is on the way up and within the first 15 mins of running. Did it with the old fuel pump too which was changed due to intermittent whine. I got a new walbro pump from usa, rated for e30 and recommended on another forum so has nice clean sock. Now that pump is starting to buzz as well......grrr.

Engine temp sensor? The plug is pretty rough but gauge reads fine. compressions are vg.........

any suggestions appreciated. Cheers Chris

[tire 10]

I had a cutting out issue similar but not quite the same as yours. It was my ECU for some reason. I put a manual one and bam, never done it again.

Based on my research, the fuel and ignition relays are the first thing to replace (under the cover on the left front strut tower.

Good luck, its a real pain.

[Etwenty1 45]

Cheers Max, I have a prefacelift 325i I can borrow to swap bits over so will give those a crack. What were your symtoms?

Also thought maybe fuel injectors.....?

[Forrest 35]

Try getting some fuel injector cleaner and running that through the car also, and maybe replacing the fuel filter while you do that, otherwise what Max has mentioned will be worthwile to check also.

[Etwenty1 45]

Ok, will have done less than 5k on fresh filter though.

[Forrest 35]

To me it sounds like what I have had with both my E30's, if you have run the tank low it picks the sh*t up out of the bottom of the fuel tank and blocks the injectors, causing similar symptoms to what you have described.

If the filter is new, give just the injector cleaner a go and see if what happens it's only $15 or so.

I am no mechanic, just going off what worked for me with personal experience.

Cheers

Edited September 30, 2010 by Brams

[Lucan 196]

Could blocked injectors as you've described contribute to a rough idle?

[pureboiracer 0]

^yeap

[tire 10]

My symptoms were cutting out at 3000rpm regardless of warmness of engine. Sometimes it would cut then come straight back on again instantly, other times it would cut and casually coast along for up to 5 seconds before coming back in again. It was definitely the ECU at fault.

3000rpm was a particularly annoying spot too, since 3000rpm = 110kph in my car!

I've never been convinced by those injector cleaner / engine flush / doohickameywhatsit magic bottles of sh*t fwiw.

Check the earths in your engine bay too. There is an earthing strap that goes from the sump on the passenger side to the chassis rail, one from bonnet to the front of the car, and one off the battery obviously,

[Jacko 2157]

Check for dodgy wiring, loose connectors etc too. Never been convinced about magic sh*t in a bottle either.

My e30 did similar stuff, drove me nuts as I couldnt work it out for weeks. Thought my coil was dying.

Turns out the previous owner had installed a kill switch and jammed it under the dash, not secured, one of the crimped terminals to it had broken wiring and would kill the ignition randomly (braking/accelerating etc)

Id look at your coil too, a mates Mk2 cortina GT had similar issues too your e30, after running out of ideas we changed the coil thinking maybe it was breaking down internally when the engine bay got warm, and it seems to have been the problem.

[Jono51 59]

plugs , coil, Ecu. is it a twin board ecu motronic 1.3?

time for you to plug and play with the donor car

[Etwenty1 45]

After thinking about the fuel sid eof things i remebered this car did have some rank fuel in it when i got it so am pulling the injectors to check. Everything up to there has been replaced, pump, filter FPR.

How does the main round plug on the injector loom come out? I have unscrewed the bottom half of the plug but cant get the top section off?

[3series 0]

I had a similar issue, which caused me to have a problem which occured at around the 3000rpm mark in every gear and sometimes would come and go but generally under load. While it was on the dyno, Gavin swapped over the coil and sure enough it fixed the issue.

Edited October 2, 2010 by bmw3

[Etwenty1 45]

Following the dirty injectors angle at the mo' anyone know how the top half of the injector loom plug comes off?

[Etwenty1 45]

Well, i had the pleasure of removing and cleaning the injectors but problem remains. Car is running a bit better (imaginery?) but not fixed.

One tip was fully gunked up but unsure if that happened during removal while wrestling with the rail. I was lucky enough to have a full set of 12 injector seals from a previous head gasket kit. I recommend circlip pliers to fit the o rings over the injector tips - easy as.

Also if you blip the accel at idle the revs choke for a moment then rev, almost like its going to stall. Doesn't affect cruising. Is that too lean or too rich?

Will swap Coil and ECU with donor car, thanks for those suggestions, and also going to check throttle switch........?

Process of elimination i guess............

[Jacko 2157]

Its 100% an ignition thing man

[Jono51 59]

Its 100% an ignition thing man

yip agreed,

also diagnosing incorrectly could introduce new faults

start with the most likely culprits first, like Coil and ECU

easy plug and play

Edited October 3, 2010 by Jono51

[pureboiracer 0]

check rotor and dizzy too, if its too worn a big spark gap can cause similar issues too.

[Etwenty1 45]

Ok will swap out ECU and Coil first.

Has new cap, rotor and plugs.

[Etwenty1 45]

plugs , coil, Ecu. is it a twin board ecu motronic 1.3?

time for you to plug and play with the donor car

So i got the coil swapped over then found my ECU has an extra row of connectors in the plug and the unit is a different size. Does that make it a twin board? Took off with different coil and car is maybe running a little sweeter ? then cuts out worse than before, just the once though, i switched off sat for 5 mins then off again and all good. Will try again tomorrow when cold.

Edited October 5, 2010 by etwenty1

[Etwenty1 45]

Getting E30 325i ready to sell and its playing up, i drive the car easy until it warms up but during mild acceleration it cuts out for half a second, like its not getting fuel? This car has had these parts replaced new over the last 6 months, Fuel pump, fuel filter, plugs, cap, rotor, valves adjusted. Strange but it only seems to do it just the once. Usually always when the engine temp is on the way up and within the first 15 mins of running. Did it with the old fuel pump too which was changed due to intermittent whine. I got a new walbro pump from usa, rated for e30 and recommended on another forum so has nice clean sock. Now that pump is starting to buzz as well......grrr.

Engine temp sensor? The plug is pretty rough but gauge reads fine. compressions are vg.........

any suggestions appreciated. Cheers Chris

I have found another ECU, the one in the car is 0 261 200 380 and the other is 0 261 203 448. Anyone know if these are interchangeable. Guess it won't hurt?

[barf 0]

some E30 ECUs are shoddy (up until the 3-row-of-pins ones), they can't supply enough current because a capacitor supplying current to the injector drivers often has dry solder joins. a piece of foam bends the PCB (part number 0 280 001 301, but not all have the large piece of foam at fault.)

[Etwenty1 45]

some E30 ECUs are shoddy (up until the 3-row-of-pins ones), they can't supply enough current because a capacitor supplying current to the injector drivers often has dry solder joins. a piece of foam bends the PCB (part number 0 280 001 301, but not all have the large piece of foam at fault.)

Have swapped coil and given battery a full charge and problem has gone away.