Juddering when accelerator slightly in use....

[march109]

I still haven't solved it either, cleaning the inside of AFM made no notiable difference for me.

[casper8r]

Cleaning the guts of the AFM has certainly improved the situation on my car, but the juddering is still there, just not as bad as it was previously.

Likewise, which leads me to suspect it's AFM's fault.

[march109]

I'll try get a spare (working and tested) AFM and fit that see it it improves the situation.

[Jonny_71]

SOLVED AT LONG LAST!!! At least it is on my car anyway. I replaced the FPR a few months back with a brand new part from GSF. Out of curiosity thought I'd swap it over with the original 19 year old BMW part this morning and hey presto, been for a long drive and NO JUDDERING!! Been said a million times before, but don't assume that because a part is brand new it is working properly. I'm just glad I don't need to fork out for a new AFM right now.

[Brianmoooore]

SOLVED AT LONG LAST!!! At least it is on my car anyway. I replaced the FPR a few months back with a brand new part from GSF. Out of curiosity thought I'd swap it over with the original 19 year old BMW part this morning and hey presto, been for a long drive and NO JUDDERING!! Been said a million times before, but don't assume that because a part is brand new it is working properly. I'm just glad I don't need to fork out for a new AFM right now.

Interesting!!
At least someone else is accusing the FPR - the same way as my investigations are heading.
Wonder if the new FPR was faulty and the old one good, or the old one was faulty and counterbalanced another fault somewhere? You really need to try another new FPR, or try your new FPR on another car without the problem as proof.

[smithy318i]

I have replaced my FPR, fuel rail, and injectors and it made no difference to the kangarooing.

Although the car is more responsive and running better than before (probably because i swamped it in carb cleaner) I have a more serious problem of water in the Inlet manifold.

I might just live with the problem until the engine blows up. (then get an M20)

[daimlerman]

When I read Jonny 71s input I went straight out to the garage and swapped myFPR.And,no juddering.Car pulls from 1000rpm in top.I can force it to judder by holding top whilst braking to force the engine to run below its idle speed,thats all.The FPR I fitted is a secondhand one of unknown vintage.Just wish that I had not ordered the Miller watsit now....

[Speedtouch]

Never mind daimlerman, I reckon you'll like the MAF anyway Did they do a special chip for your car?

[casper8r]

FPR is the fuel pressure regulater - round canister shaped thing at the end of the fuel rail has a vacuum line connecting to the back of the inlet manifold and a fuel in and fuel out.

Any ideas of how to get a hold of one and how much do they usually cost? Might as well try it out. The whole MAF conversion would be really nice too except I'm not in a position to spend money on it at the moment.

[Martinaston]

For all those still suffering with this problem you may want to close the bonnet and take the back wheels off.
Rear binding brakes has the same effect, back off the handbrake adjuster at the wheels not the cables.
See if it cures it for a while until the adjuster moves the shoes back out.

[Speedtouch]

Jonny_71, can you confirm whether the FPR you refer to is the fuel pressure regulator or the fuel pump relay?
Cheers!

[Jonny_71]

Sorry dude, it's the fuel pressure regulator I replaced.

[daimlerman]

Me too!!

[Speedtouch]

So, looks like they need genuine BMW regulators rather than GSF, etc...

[casper8r]

And where would "they" get one? Any idea of how much would one cost? Somehow going to an official dealer doesn't appeal to me at all...

[Brianmoooore]

Somehow going to an official dealer doesn't appeal to me at all...

Try it sometime! You might be pleasantly surprised.
BMW genuine parts are typically much cheaper than genuine parts for other makes of car, and you will find the dealer's attitude and customer service levels much better than the average franchised dealer.
BMW GB insist on this latter point.

[march109]

So did replacing the FPR fix it for you guys?

Interstingly I 'borrowed' a known to be working AFM and it made no difference, and mine made no diffeence on the car I 'borowed' it from. However I was going to go the FPR route, and if that failed go for rear binding brakes, if that failed I was going to take a long drive off a short pier.

However, with me absolutly not changing anything what so ever, ie. the car is back in the same state as when I first started to fix this problem, the juddering has dissapeared, knock on wood, at least for the last 600 miles, and ll my other issues have cleared up too.

Only difference I can see is the weather is colder but dryer, and I've been running it on longer journeys than normal. and haven't been buying petrol at tescos, been going to shell due to my current location. Other than that mechanically it is in the same state as before but the problem has vanished.

If it returns I shall try the FPR, anyone know bmw part number and price and I'll get one ordered, nevery hurts to have a spare. Found that out with my fuel pump .

[Martinaston]

Around the £20 mark i should think, nothing magical about them.

[daimlerman]

My Miller MAF arrived yesterday.Dan Miller requested the number of my ECU,its *** *** 172.He replied saying that it should end 173 or(I think)525.I confirmed mine as 172.So they have sent me a loan ECU,with the request that I send mine,with zone chip,for a holiday in the USA so that it can be ajusted to suit the MAF.Now unlike 320iSE,I followed Millers fitting instructions!!This involves chopping off the AFM plug(no going back now)and repositioning one wire on that big plug that fits to the ECU.I hope that my soldering skills are up to this!!I also needed to make up a bracket to support the MAF because no means of supporting it was supplied.I used the plate that came with my chav type cone K@N with a small angle bracket on one end.Making the bracket took longer than the rest of the job,of course.On the first test run the car pulled cleanly up to my current 4500rpm limit(it is only 2500 miles since the rebuilt 2.7 went in)but jerked in all gears as I slowed down through 1000rpm off throttle. On the plus side,I now have a hot idle at 700rpm,much better.From a rolling start it will pull from idle (foot off loud pedal)in 5th.No protest.Even er indoors says it is easier to drive.

[smithy318i]

I'm determined to get to the bottom of this 'kangaroo' issue, and to that end, I've invested in a 4 gas exhaust analyser today. Only problem is lack of time, but I will get there!

Any news on the exhaust gas analysis Brian?

[Brianmoooore]

Any news on the exhaust gas analysis Brian?

Yes and no! I've got the thing home (all two metres high by a metre wide+ of it), but the gas analyser isn't working properly.
It calibrates O2 OK, does a fifteen minute warm up, and then the HC, CO2 and CO should be calibrated, but unfortunately they don't.
If anyone out there knows anything about how these machines work and how they calibrate themselves, any information will be gratefully received.

[liam012]

brian
the one i use needs to be on for 24 hours before its calibrated and usually the longer it has been on the "better calibrated it is"!(i am not joking either...) - though this is not a mobile unit.
what make is yours

[Morat]

Somehow going to an official dealer doesn't appeal to me at all...

Try it sometime! You might be pleasantly surprised.
BMW genuine parts are typically much cheaper than genuine parts for other makes of car, and you will find the dealer's attitude and customer service levels much better than the average franchised dealer.
BMW GB insist on this latter point.

If you've ever had the misfortune to visit a Fiat dealer, you'll be amazed at BMW standards of service.

[Speedtouch]

daimlerman, good to hear you've got your MAF fitted. Re. the jerkiness you mention, did you allow the ECU to learn the idle setting by letting the engine idle for at least 10 minutes on initial start-up, then switch off, before going for a drive?

[funkyjoe]

Quick note about replacing the fuel pressure regulator. It seems to improve the running, but does not eliminate the kangaroo running problem. Back to recalibration of the AFM time

[Brianmoooore]

brian
the one i use needs to be on for 24 hours before its calibrated and usually the longer it has been on the "better calibrated it is"!(i am not joking either...) - though this is not a mobile unit.
what make is yours

Mine is a Sun MCA 3000, and is most certainly not mobile, except for trundling around on its casters.
When you switch on it loads the operating system, then you get a welcome screen. Press continue and the screen shows "system calibration" and quickly calibrates all the machine's functions like trigger, primary, secondary, ripple, amps, temp, etc., and O2.
Then a 15 minute countdown begins, after which the screen should show HC, CO and CO2 calibrated as well, in green.
Mine comes up "not calibrated" in red for these last three, and then displays the message "attempting recalibration".
I've only left it on for half an hour or so like this, so far, and in that time nothing more happens.
If you press continue, and attempt to use the gas analyser, it will display O2 values, but the other three are just large asterisks.

[liam012]

well the one i use doesnt have a lcd screen like that - just about 8 sort of red led screens\it doesnt give you a "calibration failed" message as such - its more of a case of looking at the readouts and thinking "if i am standing in that room i am dead" for you to knw its not calibrated - these achies are cery very tepremental and fussy - i would reccommend not turning it off for a day or two and letting it cycle over and over....

[Brianmoooore]

- i would reccommend not turning it off for a day or two and letting it cycle over and over....

Worth a try. I'll do it this weekend, when I can keep an eye on it.

[Speedtouch]

Sounds like a machine that's more trouble than it's worth...

[march109]

like my e30,

anyway a little update, still no judder, and I've done nothing to fix it, but it is starting to hunt at idle. bloody car!

[sean_318i]

I recently had a similar problem with my 325i tourer spent ages looking
for the fault it turned out to be nackered injectors. Resistance was perfect
but the spray was more like a squirt substituted with another old set and hey presto problem solved.

[march109]

A few people have mentioned inectors and even FPR, I just don't know what could cause my symptoms to come and go though. It goes for weeks withought a problem, and cures itself after a little tinkering. I never actualy changed any part that I didn't refit right away to see if it was the cause of the problem. It just seems to cure itself if I spend some time working on it. Think she misses me while I'm gone so plays up.

[gavo]

My 325 does the same juddering thing at low revs i was told it could be the maf as mine runs seriously rich but thrust bearing is also on it's way.

[smithy318i]

After pulling my engine to bits. Testing the TPS at idle and wot, and also cleaning my injectors and testing the spray pattern, I turned my attention back to the AFM (again). it would appear that my AFM isnt giving the correct reading, and after pulling off the cover and checking inside I discovered that the track had worn away.



Also the pin layout doesnt match what the manual says it should be... ?


going to tinker with it and refit it tommorow.

[Speedtouch]

Dunno if it's applicable to a 318i, but there was a good diagram on a Russian site in this thread:
http://www.e30zone.net/modules.php?name ... highlight=

- I used it a while back to wire in a MAF and it was spot on! Instead of on your diagram above running '4,5,2,3,1', the AFM ran '1,4,2,3', without the odd resistor marked '?' on the far end.