W124 e220 hfm

[grumpyartman]

My car has been stood still awhile but I've just MOT'd the old girl after failing on springs and brake pipes last Xmas. Now with a new proper spec battery, she warmed up fine and drove ok for the brake disc clean up.

I then set off for the test and the revs started playing up surging up and down about 500 revs over 3 second cycles whilst driving. She passed though.

Next time out she was fine on a short trip, so I thought the Redex had worked.

Today she played up again, and continued whilst stationery in park and neutral.

Can't see any loose vacuum hoses and its got fresh petrol, any other suggestions for my problem, please?

 

[macabethiel]

The Redex was that injector cleaner ? If its stood a while I would try a 10 mile drive with a full bottle of injector cleaner in a 1/4 tank of good fuel ?

Was it stored in the dry or outside ?

If its a petrol I would go for plug leads after that the carbon leads are easily damaged if you do not use the special tool to remove the leads from the plugs ?

 

[neilrr]

How long is "awhile"?

 

[macabethiel]

A bit longer than bwhile

 

[Vlad]

Dirty throttle body?.....its also worth noting that these 220's have electronic throttle bodies and if a simple clean doesn't work. then it could be the electronic "bit" itself which is failing....not uncommon and normally shows itself by a surging idle.

 

[grumpyartman]

Thanks lads, awhile is the six months it stood on my drive since Xmas

It was warmed up several times and moved thirty yards or so and showed no sign of its current fault.

Throttle valve is clean and moving freely.

Tried a blast out today, it didn't work, at 70 I could feel the engine rev drop and rise but so quick, one second, with a few second intervals.

Now I'm thinking fuel starvation as it stalled on me too. So as the filter is a cheap swop that will be done first.

back home the idle rose and fell 800revs every three seconds as before constantly till turn off. So the fault has a time scale relevant to the rev level.

at 3000 revs its short at one second and idle as above

Replacing the rear brake pipes meant I removed all the fuel pump tray and covers, I suppose I could have knocked something,...... out with the piggin trolley jack AGAIN!

this old lady is no beauty but i love her to bits and the dump is no place for her so i'll do my best.

 

[macabethiel]

Changing the filter has never worked on any of my cars it always ends up being something expensive !!

 

[grumpyartman]

Does this get bumped if I reply..lets see.

The old girl 93 S124 HFM E220 is still with me for another two months until the MOT when they will get her...finally the MOT guy will take her down spotting the rusty self level pipes for what they truly are and NOT PIGGIN BRAKE LINES as on every other occasion. This time the litany will be more extensive than the £17 bill last time.

The idle is better having bypassed the dead AC pulley with the shorter poly belt, she runs much smoother...but she still stalls occasionally at any time but only when stationary.

Her last duty will be a 500 mile trip to the south coast just to prove she can do it....

there is little doubt the harness is shot so the stall could be anything but one thing i would like is the opinion of someone wiser .....

Currently the plug on the unit attached to the inner wing for the charcoal canister vacuum run is detached ( plug not pipes) so the unit is inoperative. If I blanked the pipe at the engine how might that effect the running ...rich or weak??

Fairly obviously? the stall seems to come from the ecu stopping the fuel for some reason.

She is road legal and I am not spending another penny on her.....bless her cotton socks.

C'mon girl one last effort

 

[kth286]

Was that purge valve on the inner wing not pulsing when the engine got up to operating temp ?

If you can't remember. plug it on and test again.

Feel with hand on it, and you should be able to hear it.

2 beats per second when it operates.

It must only operate at certain times when conditions allow the engine to suck in petrol tank fumes, without affecting running of engine.

One of the conditions is that the engine must be up to full operating temp, and the ECU will then pulse the valve.

They usually stick in open position.

 

[grumpyartman]

Thanks for quick heads up...I can smell dinner....test it after ....a bit later.

I did read somewhere recently about it being 'open' and presume that means vacuum loss if canister done for.

If it is U/S What do you reckon on the effect of blanking the engine line at source re fuel economy? should be very marginal i would have thought.

Thanks again for answer much appreciated.

 

[grober]

Irregular idle is usually a dirty throttle body throat or gummed-up edge of the butterfly plate as already said. Assuming a leak free inlet manifold only "off the wall" thing I can think of is the tank vent filter is choked because its not being purged. This might lead to a fuel tank vacuum which might effect fuel delivery? Test would be to leave the tank filler cap loose to see if the problem went away?

 

[grumpyartman]

Cheers Grober will try that too.

Put the double pin back onto the MOT(?) inner wing unit went and got her hot .....amazed by the transformation the shorter non ac belt has made..it must have been binding a bit on the ac pulley...anyway cant feel any pulse but have good suction from manifold line when disconnected from the unit, when reconnected there is much less..... very slight suction evident from the units other side ...no pulse....so either it wasnt being called on or was closed....so not open.

She didnt stall on this occasion.....but she will.....i just ignore her

oh...and throttle body was cleaned a bit back thx.