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-   -   340 DL CVT iregular running at stationair running (https://www.volvoforums.org.uk/showthread.php?t=1283)

tmoons May 18th, 2003 20:44

340 DL CVT iregular running at stationair running
 
hello,

i just picked up my volvo 340 DL CvT from 1987. All is fine, except the stationair running... I cannt get it to run stationair with out the choke.

even after warming up (10 to 30 minutes driving ) i still drops in revs, bumps a bit (looks like is mis fires (sparkers dont go of)) and eventualy stalls... only choking it will keep it running... but it has to be on the brake to prevent getting away.

i already checked the sparkers, looked good.
replaces rotor, distributor cap and plug leads... had a little positve effect.. but still stals as discribed previous.

could any body give me any leads in to where to search furher?

thanks in advanced,

Theo Moons
Volvo 340 DL cvt '87

johnw May 19th, 2003 12:56

RE: 340 DL CVT iregular running at stationair running
 
Theo
Mine did this! The fault (in my case) was a dirty electrical connection on the idle solenoid on the carb.
The idle solenoid is there to prevent the car running on when the igntiion is switched off, but it does a good job of preventing idling if it gets no volts.
Clean the spade connectors on the engine side of the carb, hidden under the air cleaner, of course. Also check the fuses.

Others have posted further down the page on the subject of 340s shaking their carbs to pieces so while you've got the air cleaner off check all the screws on the carb.

Alternatively this can be caused by air leaks into the manifold. Check the carb to manifold nuts but don't overtighten. Also check your vacuum system is not leaking as this would also let air into the manifold.

I heard of someone who had a replacement breather hose (this is a 10mm dia hose running from the manifold round to the rocker cover) and the original hose contains a restrictor. If you blow through this hose you can check whether the restrictor is there. Don't suck - engine fumes taste horrible. Replacement restrictor are available.


A bit of a screed but this should kepp you occupied for a few hours.

tmoons May 19th, 2003 22:29

RE: 340 DL CVT iregular running at stationair running
 
i found 1 hose that was damaged...
it is the one that comes from the clutch side of the engine (or goes to ) and is conneted on the lower side of the carb (on the battery side of the car ( i do have a photo if that helps, i do not know what the function of this hose is. it the one with al the red lines on it ;))

i also started checking on the electrical part, found some corroded spades, and the earth strip from the batt. to the body work is held in place by a verry green/brown screw... (lower rev= low elect. power, stalling, higher rev= more power= no stalling).

but the steps in my book checked out good (measuring on the coil thingy under the spare wheel.)

theo

johnw May 19th, 2003 23:02

RE: 340 DL CVT iregular running at stationair running
 
That looks like the hose that supplies vacuum to the CVT control valve and the clutch servo. A break in that would certainly cause a problem.
Do let us know how you get on.

tmoons May 20th, 2003 14:48

RE: 340 DL CVT iregular running at stationair running
 
checked the egnition unit, seems fine.
power full spark when i remove the main high voltage lead from the distributor cap.

fixed the leaking hose (I did in clude a picture in the previous reply.) still no succes (seems even worse now)

next is 4 new spark plugs.

i any body has any ideas please let me know, i do not want to go to a garage and get conned there....

thanks in advance,

Theo moons

wjp01908 May 20th, 2003 21:11

RE: 340 DL CVT iregular running at stationair running
 
Have you checked over the carb as suggested theo?

It does sound as though this is at fault (assuming that the engine only runs poorly on idle - I would expect an ignition or engine mechanical fault to give problems throughout the rev range)

I would check that the idle solenoid actually operates as well as the electrical connections then perhaps dismantle the carb and give it a good clean - especially the air correction jet & emulsion tube. A good squirt of carb cleaner and a blow through with some compressed air should sort them out. Also check that all the adjustments are correct as per the manual

Is the choke correctly set? ie does it open completely when the knob is pushed in - a partially closed choke will give an over rich mixture when the engine is warm leading to the and stalling you describe - however I don`t imagine in this case that using the choke more would help. Looking at the picture you posted the choke is partially closed - if the knob was in at this point it needs to be adjusted so that the flap is fully open.

Is the air cleaner blocked? Try firing it up with the element removed or with the top off.

Good luck

Will Plummer

tmoons May 21st, 2003 02:03

RE: 340 DL CVT iregular running at stationair running
 
UPDATE....

changed the sparkers...
re fitted the damaged pipe....
tried it without aircleaner...(does run but still has the same probs...)

so now it has
new (see mails before) plus new sparkers, and fixe hose,
still not happy...
did some parking lot wrecking to night, and after that i all sounded a lot BETTER, no choke needed to keep it ideling... running was nice and smooth (due to previous changing in idle screw settings it ran a little high (difficult changing from d to n to r and so on)
but after a little while it ran irregular again....

so with this new look upons matters, any ideas?

still i suspect the spark department.... or something in the carb dealing with low revs (it is some times also nothiceble in low speed cruising....)

looking forward to read any thing....

theo

wjp01908 May 21st, 2003 06:47

RE: 340 DL CVT iregular running at stationair running
 
"parking lot wrecking" ? Whats that?

I would be a bit wary of increasing the idle speed to mask this problem. Difficulty changing gear shows that the clutch is engaging and will be wearing while stopped, while crashing the gears will do them no good in the long term. It must be doing some speed.

As you suggest the carb does have a seperate idle circuit that supplies fuel/air mixture to a point BELOW the throttle valve in the bottom of the carb. (At idle the valve is nearly closed and there is not enough vacumm to pull fuel through the main jets higher up - the choke creates extra vacumm and sucks extra fuel out of the main jets when closed).

This may be blocked suggesting a thorough carb clean is needed.It is not an especially complex carb to dismantle and you dont have to completely disassemble it. Do it off the car on a clean bench and use plenty of carb cleaner with a thin plastic tube to blow through the various passages

If the vacumm is low due to leaks etc. this will also result in poor fuel supply at this point. Though you have checked the pipes, there could be an internal fault in one of the various valves/ servos etc that is leaking air to the manifold. A check with a vacumm gauge should show whether this is the case (you can get fairly inexpensive ones that have coloured bands for good/poor as well as the numbers if you are not sure what they should be) Or you could check more simply by pulling each hose off the manifold in turn and blocking the hole with your finger. The one that is improved by this is the one that is leaking. It will then be a case of double checking the pipework to the item concerned or repairing or replacing the offending item. (cross your fingers it`s not the 4 way valve or other expensive bits!) It may also be worth checking that the inlet manifold nuts on the cylinder head are secure and that there is no leakage at the carb / manfold join.

Good luck

Will Plummer

pettaw May 22nd, 2003 01:47

RE: 340 DL CVT iregular running at stationair running
 
I would suspect an air leak, the best way to test this is by using WD-40 or an unlit blowlamp and wave it around all the hoses and particularly the joint between the inlet manifold and the carburettor, these gaskets can crack inside but look fine on the outside. When you find the leaky joint, the revs will rise suddenly to a much more normal idling rev.

PLEASE DO THIS IN A WELL VENTILATED AREA, because the idea is that the vacuum leak will pull in this basically flammable spray or gas that you're holding near to it and cause the combustion to suddenly enrichen.

Once you've tried that, come back and we'll try to advise you what to do and what it might cost you in terms of parts.

Andy

tmoons May 22nd, 2003 10:06

RE: 340 DL CVT iregular running at stationair running
 
Hi all,

I made an appointment with the official Volvo dealer her in my town.

Friday morning 8 o’clock... they do the diagnoses; I do the fixing (if any)

but still I do not really get the vacuum problem thing, if my carb is leaking air, the mix should get really lean (to much air) and that is not what is happening, the mix seems to be getting or really rich, or does not get Ignited, and blows up in the exhaust pipe ("farting" when slowing down).

Still all remarks and comments are appreciated.

Kind regards,

Theo moons
(Holland)




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