340 1.7 engine problems

[DennisFrancis]

Hi,i am having a problem with a friends 340 1.7,it starts ok from cold but if you go about 1/2 mile or so and stop at a junction or something,go to pull away it tends to stall and will not start again,it turns over and dose not fire,it seems like it floods,has to be left about 20 mins,then starts ok and ok rest of day,have fitted recon carb,also ign,system seems all ok,any ideas ?.

[morgan105]

check and clean the CPS (crankshaft position sensor). It may be dirty and not reading the top dead centre mark properly.

[DennisFrancis]

Thanks for that will check and clean sencer at weekend let you know how it go.

[DennisFrancis]

Hi again,am now a very happy chap having cured engine problem thanks to your advice to clean sencer,bit of a bugger to get to but worth it ,many thanks.

[Susanne]

Hi Morgan,

Do you think the CPS sensor could be the cause of a similar problem on a 340 1.4?

My poor '89 340 vario starts up just fine but after warming up a wee bit and getting me about a mile from home seems to bog down and stall when at a stop. Just like happy chap Dennis' car, it will turn over when you try to restart it but seldom catches. It sometimes will give a few hiccups as if it's about to start but then conk out again. After you leave it alone for 5-10 minutes it will start again and go ok for a bit. It "feels" as if it's flooding.

I confess to doing the old left-foot-in-the-brake/right-foot-on-the-gas to keep it going. Bad, I'm sure, but a gal's gotta work!

We just got done having it worked on at the Volvo garage (instrt pained pocketbook look here) for problems with super rough running and the alternator, dist cap and spark plug cables were replaced. I'd like to be able to go back to the garage with a firm suggestion about what to check this time.

What exactly IS the CPS sensor, anyhow? I have to admit to being a total dunce when it comes to these cars with their variomatic trannys, though I think I'm fairly knowledgeable about cars in general.

Thanks for any help,

Susanne

[5lab]

on a 1.4 its much more likely to be carb bolts. grab the air filter (big black thing) and give is a wobble. it should not move at all. if there is play between the filter and the engine, theres yer problem

the cps tells the car when the engine's shaft is at the 12'oclock position so that the reenix unit knows when to send the 'spark' to the engine.

[morgan105]

Hi Susanne,

The CPS is the crank position sensor, it is located on the top of the bellhousing just behind where it connects up to the rear of the engine (you'll see it if you stand at the left hand side of the car and look down the back of the engine to where the bellhousing bolts up). You will not miss it when you see it as it has a wire running in to it and is held in place by 1 bolt. Now this may need taking out and cleaning but be careful as you do, and don't pull on the wire to get it out. Once it is out you just need to clean the tip of the sensor and then put it back in.

I couldn't definately say this will be the problem with your car but it will help it anyway.

Going by the excessive rough running that you mention, I would check all the vacuum pipes that are associated with the variomatic. All the vacuum pipes at the carb, all the switch valves that the pipes go to and come from and the pipe to the de-clutching servo. Check all the pipes for splits and that the connections are good. My dad's 340 vario had the same problem as yours and it turned out to be one of the vacuum pipes at the small switch valve located on the inner left wing, the one that also has the second pipe that goes down to the de-clutching servo, had come off it's connection but was occassionaly resting over the hole to make it run smooth. From looking from above it looked ok but when I physically checked it it was hanging loose, plugged it back on and it's still running sweet as can be, but if I disconnect it the car has rough running, stalling and is a pain to start. Does that sound familier?

Another thing to check for is loose carburretor bolts and screws. If you're going to check for loose bolts and screws on the carb then there is one thing you will have to do on this one, the 340 1.4 carb has a screw situated underneath the heat shield and can come loose and cause an air leak, so you need to take the carb off to get access to this one screw, tighten it, and then put the whole carb back on.

Start with the easiest first that you can check, start with the vacuum pipes then check the CPS and if still not right then go on to the carb. With luck you may just find a loose pipe somewhere, probably the same place as the problem with my dad's which was the longest pipe that goes from the right hand side of the car over to the left and connects at the little switch valve before going to the servo.

I hope I haven't messed your head up to much with all this info, I just hope you find the problem quickly and you can save yourself some money and spend it on other things instead of on a garage for fixing it.

Best of Luck with it!

Let me know how you got on with the fixing.

Here to help if I can.
Morgan

[Susanne]

Hi again guys,

Sorry for the delayed reply, but life got in the way. Doncha hate that?
First of all, thanks very much for the suggestions.

Well the red bomb is still not working right but we did try some of the suggestions you had.

Oh, luckily the problem of the sputtering running had already been fixed with the replacement of the afore-mentioned parts by the garage, so all that was (and still is) left is the stalling at stops problem.

I have not been able to positively identify and clean the CPS though. On my car there is a electrical wire bundle (looks like 2 wires) leading to a fitting on the upper left side of the bell housing but it seems to be connected to a metal bar that is screwed into the housing with 2 bolts. Is this the CPS?
I assume to remove this I would remove both bolts, gently pull the assembly from the bell housing, and clean it up. Yes?

Oh! Something else sort of a shocker for me was when we removed the air filter assembly to get at the carb (all bolts and hoses seem ok, BTW) and I saw that there is only one butterfly valve in the carb. Can this be right??? There are the 2 barrels and the one on the left side of the car has a butterfly dealie that moves when you apply the choke. However, on the right barrel there's the rod, with a slot and screw holes but no metal cover-looking piece.

Has the garage that worked on my car ended up with spare parts lying around... from my car?

Thanks again for any and all help!

[redline]

grab the air filter (big black thing)

patronising bugger

[5lab]

Oh! Something else sort of a shocker for me was when we removed the air filter assembly to get at the carb (all bolts and hoses seem ok, BTW) and I saw that there is only one butterfly valve in the carb. Can this be right??? There are the 2 barrels and the one on the left side of the car has a butterfly dealie that moves when you apply the choke. However, on the right barrel there's the rod, with a slot and screw holes but no metal cover-looking piece.

Has the garage that worked on my car ended up with spare parts lying around... from my car?

dont worry about that - some carbs had 2 flaps, others one. the downpipe without the flap is only used at 2/3 throttle and above, once the other flap is fully open, so doing it this way allows more peak power i think.

have you tried just adjusting the idle speed? if it stops EVERY time you stop driving, it sounds liket he idle speed is simply too low. twist the screw in a full turn clockwise and you should get a bit more stability

[Susanne]

have you tried just adjusting the idle speed? if it stops EVERY time you stop driving, it sounds liket he idle speed is simply too low. twist the screw in a full turn clockwise and you should get a bit more stability[/quote]

Thanks for the info about the carb flaps, Slab. The only ones I remember seeing were the big old 4 barrel from old US cars. Quite different!

I don't think the prob is just the idle speed, because I've tried driving with the choke a little bit on and sometimes it would stall even then.
The only way I could be fairly sure that it didn't stall out at a stop was to basically not let the car drop out of gear.... that one foot on the gas/one on the brake thing I mentioned in my first post.

Now, I am fully willing to be advised that the idle speed increase might work better than leaving the choke on halfway. In fact I'd be delighted if it was something that easy. Hmm, I may just try it anyhow. Can't hurt, after all.

Thanks,

Susanne

(Redline, I almost got miffed at the "big black thing" as well, but face it, how many women know much at all about cars? And I did say that I was a bit of a dunce about these in particular! )

[5lab]

sorry for the black thing :D


if you back right off the trottle at a speed, with the car in gear, does the car seem 'jerky' or is it smooth? when it cuts out, does it happen suddenly, or does it seem to slow down and eventually cut out?

oh, and is it creeping forwards at all when you have it in gear but nothing on the gas?

[Susanne]

No worries and no offense.

Wow, some thinking needs to go into these answers. I haven't been driving the car often, as you can imagine.

OK, here goes -
Backing off of the throttle at speed - I can't remember a difference between how it is now and how it was when it was running well. Truthfully, it always seemed "jerky" in comparison to regular automatic tranny cars.
But the engine doesn't stutter, if that's what you mean?

When it cuts out - It seems to just die peacefully. The revs go down fairly fast and before you can hit the gas or pull open the choke it's too late.
Again, it doesn't stall every time. We were messing with it today and I took it for a spin around the block and stopped a few times but it kept going fine. Then when I pulled into the parking place and put it in neutral it immediately died.

Creeping forward when no gas is applied - Nope. This I do know for sure. It's staying put until you apply the gas and it kicks in and starts going.

5lab (sorry for reading that as Slab, BTW.. LOL) thanks for all this help. I sure do hope this is something home fixable or that the garage can find quickly. Otherwise I'm not going to be able to afford to keep the little red gal.

Susanne

[5lab]

ok well i can tell you that..

the clutch is fine (disconnecting properly, if it wasnt that could stall the car)
the idle amount is fine (if not, it would stall *every* time i think
if its not juttery then mixture is probably alright.

does it ever seem to loose a lot of power when driving??

[Susanne]

Well, this question I just can't answer. It's been too long since I drove it at more than 30 km/hr like today, to be honest.
But there isn't any time that that sort of situation spring to mind since it was repaired at the shop last month.

Would the CPS cause an intermittent problem like the stalling, do you think?

I think tomorrow I'll crank up the idle one rotation as you suggested, just for sh!ts and grins. Can't hurt, right?