"P" reg 406 1.9td smoke problem

[jasper5]

Before you do anything serious, buy some Wynns Diesel Clean or similar, such as Forte injection cleaner, remove the fuel filter, empty the filter housing, put a new fuel filter in then fill it with the Wynns, bleed up the system and run the engine for a good 20 minutes.

[StevieboyTD]

I have removed and refitted my Fuel strainer and it is perfectly clean.

I have also managed to track the slow aceleration to some weird contracption on the fuel pump under the bonnet. It's like a small black shock absorber that connects to the accelerator arm on the pump. If i just grab the accelerator arm and accelerate it quickly to full then the engine accelerates quickly also.

Could i remove this thing, or should i get a new one?

Take it off, burn it, bury the ashes, then burn the ground you buried it in.

[poddack]

By law you can make a journey to and one return journey to a pre-booked MOT garage in a car without TAX or MOT. I have disabled my EGR by sticking a 2p piece in the air intake distributor with some instant gasket and it has made a small difference.

[poddack]

The slug was mine.

[vortexco]

Ok the black slug thing is coming off tonight,

At the week end i will get a fuel filter and i bottle of diesel cleaner, fill up the filter housing with the cleaner and run the engine!

Thank you for all your help, although i could not see any black smoke last night, but it had started to get dark by then.

[Welly]

This problem sounds like it's to do with the cold start high-idle mechanism and somehow it's slowing the action of the accelerator cable.

I think Swiss had a problem with his so may be able to help further.

The smoke? dunno could be to do with the above? the injectors rarely give any trouble to be honest.

[vortexco]

I'll look into the cold start cable, but I'm sure that on my 405 the cold start is on a separate arm to the accelerator, and I assumed that it was the same on the 406!

I'll have a look tonight.

Thank you

[Bundy]

Any idea when the timing belt was last changed? it could be your pump timing that's out. One tooth out on a mechanical diesel will make a big difference. Fuel going in to early will make the engine louder and cause light grey/white smoke. Fuel going in to late will cause the engine to run quieter but it will belch out black smoke. Both will kill performance though.

The cold start/fast idle circuit on these engines is very, very basic, it's just a solenoid switch that allows vaccum to reach a diaphragm that pulls on a cable. The cable then pulls a small arm on the fuel pump and richens the mixture a little which in turn increases the idle speed a few hundred rpm. The solenoid is very prone to failure but you wont see ANY side effects other than your car idling at 1200rpm instead of 800rpm, i did about 15000 miles with my solenoid dead, i just used a little more fuel and had a faster idle than normal.. The fast idle circuit only works in these cars at idle and at cruising speed, under any acceleration it turns on to provide the engine with more fuel (and thus, power) and doesn't go off again until the speed/engine load levels off again to help boost fuel economy.

You can see the diaphragm on the right hand side of the inlet manifold (looking from the front of the car) and can trace the cable back to the fuel pump. With the engine up to temprature, rev the engine and watch the cable, you should see it pull/release as you rev the engine up and down. if not then either the vaccum hose has come off the circuit somewhere or the solenoid is dead. The solenoid is mounted to your brake servo so isn't hard to find or replace, but check the hoses that go onto it and the diaphragm as they are bad for splitting and falling off the barbs. If they are split, just trim them a little and push them back on. There are two hoses ont he solenoid, one from the diaphragm and one from the brake vaccum circuit.

[vortexco]

Ok spoke to the man who gave me the car, he is unsure when the cam belt was changed, so i am going to have it changed. and the engine does seem a little louder than it should!

also i have moved the car onto concrete and have noticed water dripping from what looks like from under the cambelt. Is the water pump there? maybe i should get that changed as well.

also when the car is warm the fast idle does not turn off, and i can't see the cable moving when i accelerate the engine. so i will look into that!

The slow accleration is due to the acclerator cable being sticky to i am going to have this changed!

Seems like quick a lot of work, but considering the car was free to begin with!!

Thanks for all your help.

[tenwierdufos]

yep sounds like the waterpump to me

get a proper timing belt kit dont just change the belt itself, will include tensioner, idler, waterpump and the belt itself.

usually works out at about £70-£80 for the timing belt kit



and avoid driving / running the engine untill you have changed it!!!, if that waterpump goes the belt will come off

[Bundy]

Ok spoke to the man who gave me the car, he is unsure when the cam belt was changed, so i am going to have it changed. and the engine does seem a little louder than it should!

also i have moved the car onto concrete and have noticed water dripping from what looks like from under the cambelt. Is the water pump there? maybe i should get that changed as well.

also when the car is warm the fast idle does not turn off, and i can't see the cable moving when i accelerate the engine. so i will look into that!

It's not a quiet engine to begin with remember, lol. Mine rattles like a good un when it's cold and is unmistakably a diesel when it's hot, far from silent.

Indeed, the waterpump is under the cam cover towards the rear of the black plastic cover.

Sounds like your solenoid valve is scrolloxed then. Think mine cost about 17 quid from the stealer. Could just be the vaccum pipes have split and come off though so check them first.

[vortexco]

One thing I forgot to mention, is that the cold start is jammed on as the car fast idols from cold and does not slow down when warm! Does this change anything?

[Bundy]

One thing I forgot to mention, is that the cold start is jammed on as the car fast idols from cold and does not slow down when warm! Does this change anything?

Nah, just makes it idle a little higher

[swiss]

Yes, the 1.9 is a noisy bugger. People stare at mine as if they expect a tractor, not a saloon car. She loud.

Re: the fast idle. Mine is jammed on. There's a small hose which taps vacuum from the vacuum pump and when the fast idle temp sensor warms up it's meant to open a valve to put vacuum on the fast idle cable which slows the revs down. 'Cept it's shagged. So, thought I, being a clever dicky, since one doesn't really need fast idle in this climate anyway I'll just ramp down the fast idle speed screw, craftily hidden on the back of the pump. Problem was when the revs dropped to 1000, the engine started leaping about like it was trying to escape the bay and sounded like it was on the verge of stalling. So in the end I just forked the whole thing off and let it idle at its preferred, embarrassing speed.

Now, as these fine folks have suggest your first call with the injectors is to wop a load of cleaner through 'em. If you wallet needs lightening you can pull the injectors and send them off to a diesel specialist who can clean them up and reset the break pressures or supply replacements as appropriate. Injectors do need regular resetting/replacement, just not as often as things like filters or the usual service items. Generally no-one ever bothers. I'd do mine but my wife spends all my money on curtains and things.

The lack of power combined with black smoke is suggesting to me either your injectors are knacked and/or your timing is out. So yes, get a chap with knowledge of these matters and have yer belt changed and your timing reset (or grab a Haynes manual and try it yerself).

On top of all this, my clutch slips like a greased-up weasel. So now I have to go and feel sorry for myself.

[Bundy]

On top of all this, my clutch slips like a greased-up weasel. So now I have to go and feel sorry for myself.

Ouch, I changed my clutch (and gearbox, wife damage) on my 406 a few years ago, not a fun job. I only did mine because i had the box out anyway, The TD clutches have a rep for being nighe on bullet proof.
I'm having a sympathy beer for you as we speak