Juddering when accelerator slightly in use....

[Brianmoooore]

How are you getting on with this problem Brian?

'Fraid I haven't looked at it since. The problem only affects my wife's touring when it's running on petrol, and I solved the LPG problem instead!
Running on LPG better than it ever has now - even starts from cold on LPG easily, which it never did before!
Ought to check out the FPR though, as that would explain the very small amount of petrol consumption that it seems to have.

[k]

Firefly....I would add check valve clearances, not to tight, and compressions on each cylinder balanced.

[jone23]

I've also heard someone one here saying that the o rings in the crankcase to intake manifold pipe can perish causing an air leak. Likewise with something around brake servo/master cylinder i think. However, i have no experience myself with either of these solutions.

[Martinaston]

Firefly2005
You could probably add worn gearbox bearings to your list.
I hope it doesn't get too long or i'll never sell another E30

[daimlerman]

Just reread this thread,my yellow service light came up at the weekend.Yesterday I changed oil and filter and stuck a new set of spark plugs in.And guess what?Yup,my splutter at around 800rpm has vanished.Now its not the fresh oil so it must be the NGK BPR6ES plugs....at £1.03 (plus VAT) each from Partco...how did we all miss what is now so blindingly obvious?

[asmith88]

i dont understand how it can be spark plugs when it runs fine the rest of the time, surley if it was plugs it would always splutter.

[zaust]

Have you checked the gearbox mount's and the prop doughnut, and also to see if the weight has fallen off the prop ?????

[Brianmoooore]

,my splutter at around 800rpm has vanished.Now its not the fresh oil so it must be the NGK BPR6ES plugs....at £1.03 (plus VAT) each from Partco...how did we all miss what is now so blindingly obvious?

Because your's is a different fault from what I understand most on this thread to be.
A 'bogging down' underaccelerationn from lowish revs is a well known ignition fault, and although changing plugs may have cured yours (until they begin to wear), the real problem is likely to be the distributor cap and/or rotor arm.
The fault mainly under discussion on this thread (as I understand it) is a slight hesitation/kangarooing underaccelerationn.

[SickEddy]

hi. i have just bought another e30 and this has the same problem, at 1000-1500 revs it kangaroos. its a 325i sport with high lift cams (aparently this could be the cause on its own). i have tried changing the AFM over from my old car (320i) and made no difference but havent got around to trying anything else. it is worse when the engine is cold.

[Martinaston]

I'm pretty sure mine is due to a worn gearbox, i've checked everything else and it all works fine.
The reason i figured it was the garbox is due to the amount of play in the prop shaft with the rear jacked up and the car in gear.
An easier way to check is to park the car on level ground, take the handbrake off and put the car in first gear.
Then rock the car backwards and forwards without pushing it so hard that the engine turns over.
Idealy if there is no play in the drive train the car should not move at all

But considering most E30's are in there twenties then there will be quite a bit of movement.

So if all the people who suffer from the kangeroo problem measured how far the car rocks back and forth while in 1st gear.
We could then compare the distances and get a rough idea of how worn the gearbox (drivetrain) has to be before the kangeroo rears its head, so to speak.

I would go first and put the measurement up but the cars locked away
I can say for sure though that its ermm...... Lots

I'll get the tape out tomorrow and post it up, if anyone else wants to post up before then, then go for it.
Best way i guess is to measure the gap between the bumper and a solid object.
It may be worth mentioning the mileage as well but i don't know how relevant it will be, its more likely to relate to how much abuse the cars had.

[markus_74]

driving through town traffic at 1500 rpm is a feking nightmare in 5th and 4th.
3rd is a little better,as the revs are higher.

please someone, solve my shit engine fault.

dear, smithy

i got same problem with you and after i replace with my friend new afm the problem is solve.

i open and check my afm and find that the carbon track that is at 1500-2000rpm is very very thin or nearly disappear, so my conclusion is there is an afm.

[Speedtouch]

driving through town traffic at 1500 rpm is a feking nightmare in 5th and 4th.
3rd is a little better,as the revs are higher.

please someone, solve my shit engine fault.

You're asking a teeny 4-pot to shove 1.25 tonnes of car at barely above idle speed in high gears through traffic! It's just hinting at you that it's on the verge of stalling and needs a lower gear, surely?

[Martinaston]

I eventualy got the tape measure on mine yesterday and measured the amount the car moves while in gear.
While rocking the car it moves back forth by 28mm so its got quite a bit of play in the gearbox. I know its not down to the half shafts becausee they have only done about 3k miles from new and the diff is in pretty good shape with no signs of wear on the teeth at all and no play in the movement and a new clutch with about 600 miles on it..
All the slack in the drive train is down to the gearbox that i'm using thats from my original 83 320i thats been used in various cars over the years and must have covered well over a 100k by now.
I've never pulled it apart so don't weather its worn layshaft bearings or worn cogs, judging by the chatter at idle i think most of it will be down to the bearings.

So i'll say the car (box) has done 100k with 28mm of play.

If anyone else wants to get the measure out and post the results so we can compare, it would be appreciated. (just re-read that, cue the silly comments )

As for all the people that have changed the air flow meter and cured the problem, i'd be willing to bet that if you dissconnect the battery so the ECU has to re-learn its settings with the new meter that the problem would return.
If its running a map with the settings from the old air flow meter then it probably has a very slight overfueling that is masking the wear in the drivetrain.
Anyone willing to give it a try ?

[zaust]

I do agree with that,

But have also found recently with my own, That there is a in built fuel cut out in the ecu set at around the 1100 rpm mark. Haveing just remapped mine, And raised the paramiters I found this to raise as well. It will casue a feeling like kangroo jucie and there is not much you can do about it unless £££s are involved.

[Martinaston]

You mean the cut out for when your coasting in gear?
When you hit the gas and the fuel is switched back on, i guess the ECU has to calculate just how much fuel is needed.
Perhaps the old motronic is just not up to the job and its been hidden by that big doughnut on the back of the gearbox.
Stick a faster processor in and see what happens, Intels are good but AMD's are a bit cheaper

[zaust]

That's the one, I have seen a couple of times where they are slightly higher than they should be. And now have the same.

[Martinaston]

What would happen if the TPS was moved so it clicks slightly later ?

[zaust]

Try'd that, Same same but with a slight bog down at the start..

[Martinaston]

So its down to a gap in the rev range between the idle map switching off and a take up of the running map as the fuel kicks back in ?

[zaust]

Exactly. When you re map or chip, in some ecu's it will raise the cut out too. Unless i go msd or simular, there is not much that can be done about it other than going back to standered.

[Martinaston]

I guess that WAR chip is looking tempting.

[bpowell555]

Well, mine had this and now my fuel pump died, whether due to the relay I don't know. So I'm hoping it was due to weak fuel pressure, on throttle but before wot ... Some cleaned injectors should make it run better still. I guess I'll find out once my fuel pump is sorted....

[markus_74]

May be this can help:

I have a few afm from 203 and 134, I have change it but the problem is still there.

so, I take all my intake manifold, clean all the hole at the throttle body, especially small hole that connect to the vacum hose.

and the very important is proper adjust the TPS.

loose the screw at the back of the accelerator that hold the cable, so it can move free and the butterly can closed perfectly, ah may be my language is difficult to understand but I mean that the throttle body flap must be closed perfectly before you can adjust the TPS.

all clean and then I replace it.

My engine is cure with kangaroing when slow and low rev.

may be this can help

My car become so responsive and feel good.

[bpowell555]

driving through town traffic at 1500 rpm is a feking nightmare in 5th and 4th.
3rd is a little better,as the revs are higher.

please someone, solve my shit engine fault.

dear, smithy

i got same problem with you and after i replace with my friend new afm the problem is solve.

i open and check my afm and find that the carbon track that is at 1500-2000rpm is very very thin or nearly disappear, so my conclusion is there is an afm.

I tend to agree with this though I'm going to give my tps a clean first. This video is the nuts for showing why a fubarred afm will provide a similar jerkyiness on throttle application to tps but only at certain revs.

TPS is off, on or full, but AFM is more sensitive and cause lumps in between the "on" section.

[youtube][/youtube]

[bpowell555]

Well, mine had this and now my fuel pump died, whether due to the relay I don't know. So I'm hoping it was due to weak fuel pressure, on throttle but before wot ... Some cleaned injectors should make it run better still. I guess I'll find out once my fuel pump is sorted....

Dead fuel pump replaced; running well so going to clean tps and then adjust the track on the afm.

[Green]

Having some major juddering recently, and it's increasing.

Basically sometimes when I start the car from cold it'll idle at 1500rpm and may eventually drop down to 700rpm again after a bit or after i rev it.
Other times when the car is warm and been running I've put it in neutral to coast and it's been once again say 1500rpm or slightly higher.
When it's like this it'll judder under 1500rpm.

But I've also recently had the growing issue of the car juddering at when I'm just driving along in any gear occasionally which varies from cruising speeds to perhaps a bit of hard accelerating.
Tonight for example after i down geared into second and then gave it some abuse, it sort of just started to judder, then lost all throttle response for a moment and was erratically idling in neutral up and down from 1000-2000rpm a few times before returning back to normal and regaining throttle response.

This topic worries me a bit thinking it could be a gearbox and clutch issue, as I noticed earlier underneath the car that my gearbox has a film of oil substance on it, and also appears to slung some off around the where it joins onto the prop so that it had splashed onto the underneath of the car.
My injectors are very noisy as well i realised today (thinking it was my lifters) so could it just perhaps be this and a dodge FPR?

[KimH]

I think this must be a common symptom with a number of different causes. My 325 has done this intermittently since I got it some 3 years ago and it seems to be getting worse. The car pulls well and never hesitates under acceleration ”“ it just kangaroos when trying to pull away gently or keep the throttle slightly open in slow traffic. I am at a loss but have noticed that if I hold the throttle very slightly open with my fingers when the car in neutral and idling (which it does nicely at 600rpm) the revs rise and fall as if I was blipping the throttle pedal (hunting).

I am going to replace the TPS next ”“ more in hope than expectation. (I've already swapped the AFM and FPR, admittedly with used items, without affecting the symptoms at all).

Update: Replacing the TPS made no difference - which would have been nice as the engine had started to misfire horribly above 2500 rpm when trying to accelerate. There is a noticeable hesitance when cruising ”“ like a single cylinder intermittently though not regularly misfiring ”“ and at anything other than gentle acceleration a total loss of urge to the point it feels like it’s about to die. Back off the throttle and all is well again. It revs quite happily in 1st, 2nd and 3rd well past 3000 rpm so I guess it’s not fuel starvation; I never smell unburned fuel and it has never backfired; I’m still averaging 350 ”“ 400 miles per tank so consumption has not suffered (I do a lot of mainly motorway driving); I’ve taken a couple of the plugs and they look good (they were new some 8000 miles ago so I guess they’re still OK); it idles very well and pulls like a train when cold.

Crank Position Sensor reads 560 Ohms and the blue temp sensor 2.7K cold and 300 Ohms hot ”“ so no obvious faults there. But”¦”¦ After a 125 mile journey today, which did not fill me with confidence I would make it home, I plugged a new blue temp sensor into the connector, I didn’t screw it into the Thermostat housing in place of the original ”“ just left it lodged against the housing to get warm ”“ and the car ran like a dream. I was even able to cruise at 25 in 5th on idle without the engine trying to jump out of the bay.

I’ve left it for the night to cool. I’ll give it another 250 miles tomorrow and post an update.

Mine's FIXED!? Ran like a dream today - purred and pulled like a train, backto its silky smooth acceleration in top and no misfiring or hesitance. I'll pop the new blue sensor into the thermostat housing asap, bin the original and enjoy the car again.

Update: the misfire returned, I swapped the crank sensor without resolving the issue but a spare set of second hand HT leads has again restored the silky smoothness of a straight 6. 2 steps forward, 1 step sideways and 1 step back. I will get there in the end.

[brummimatt]

I've got a similar problem. When pulling away and the clutch is all the way off, with small amout of throttle the car Kangaroos pretty bad. Not so bad in 3rd 4th and 5th.

Also though, when i accelerate and then drop of the throttle the car feels like it suddenly jolts. as if the back axle is wound up then unwinds. Is this all part of the same probelm??

[Green]

Think i found my problem



Forgot to change them when I did my engine, whoops.