Page 1 of 2

Volvo 340 1.7 splutters and cuts out

Posted: 03 Jul 2019 07:44 pm
by Benparker
Hi everyone
Any gone got any pointers would be greatly appreciated.
I have an 88 volvo 340 1.7 that has a lack of power when accelerating heavily or driving up hills.
Sometimes it will struggle up hills with barely any pressure on the pedal, but most of the time it bunny hops and can lose power to the point of cutting out.
It might start straight up again or take quite a few pumps of the pedal to get going then a fast idle for a while. I have not yet tested the fuel pressure, but will borrow a tester to use at some point.
so far i have replaced the plug leads and lead from the coil, the spark plugs, distributor cap, rotor arm.
I have refitted the original solex carburetor (as it had the 1.4 weber fitted when i bought it) and tuned it up.
I have confirmed the vacuum unit works with the engine running, as the engine revs rise when the vacuum is connected. I have tried a replacement renix, i have cleaned the coil contacts (both sides) and tested live and earth to the renix (9.4v cranking and 0.1 ohms) tested the flywheel sensor (289 ohms) and cleaned any particles on the sensor tip, and the coil (0.8 ohms across the two contacts and 6.8 ohms from contact to output). I have ordered a replacement flywheel sensor and coil to fit as the readings are both slightly out of spec per Macs fantastic guide to renix units.
Running out of ideas sharpish so looking for advice from anyone with more experience with these engines.

Many thanks

Re: Volvo 340 1.7 splutters and cuts out

Posted: 05 Jul 2019 11:37 am
by 360beast
Have you checked for vacuum leaks on the engine? Spray wd40 around it and see what happens.

Re: Volvo 340 1.7 splutters and cuts out

Posted: 05 Jul 2019 09:17 pm
by bogbasic
Carb idle solenoid. Look no further.

Re: Volvo 340 1.7 splutters and cuts out

Posted: 06 Jul 2019 02:12 pm
by Ride_on
Might not be your problem but a common issue is weak spark caused by oil in the distributor. Seal placement is critical especially if there is a wear lip on the cam.
Usual symptom is stalling when pulling off at junctions.

Re: Volvo 340 1.7 splutters and cuts out

Posted: 23 Jul 2019 02:43 pm
by Benparker
So i have managed to find a brand new idle solenoid in the Netherlands, so that went on. There is definitely a vast improvement, however there is still a splutter/lack if power if driving up hills or accelerating using over half pedal.
I have also recently changed the oil and filter to help smooth the engine out.
Struggling to keep interest in the car whilst it is running so badly, was hoping to take it to a couple of shows this year.

Re: Volvo 340 1.7 splutters and cuts out

Posted: 23 Jul 2019 08:00 pm
by bogbasic
Another common problem is air leaks from the carburettor gaskets - i.e. the ones that go each side of a spacer between the carb and the inlet manifold. Its quite easy to make your own with a cornflakes packet, or even some proper gasket material and this might give a further improvement. If you changed the gaskets when you did the carb, you can forget this one. Are the fuel hoses looking good? Poor fuel supply can cause the engine to get very weak.

Re: Volvo 340 1.7 splutters and cuts out

Posted: 04 Jan 2020 08:07 pm
by blackVolvo
I have a little same problem:

So I bought a -86 good conditioned 343 with 1.7 engine, 5 speed gearbox. Has 150 000 km on clock.

It had nice idle and all, no splutters. Hard to start though when warm, seems to not get petrol. But it has new petrol pump fitted last summer.

But after I bought it, 500 meters and it stalled. Pulled choke and got 200 meters, it died again. It had stood for about 6 months, with petrol tank almost empty so I got it towed to gas station. And filled it. But after that, same thing. it will die if I push accelerator even to halfway. pumping gas and playing with choke got me home ( last mile with only choke pulled full out, using it as cruise control). If I touched to accelerator, it would die.

So now what would be the main cause for this and what parts should I get? This will be my daily driver so I need it to be reliable.

Checked to idle solenoid. The solenoid clicks when removing and inserting number 10 fuse. So it is ok, i think.

My friend should clean the carb and check if there is something wrong with the carb on monday. One thing, I noticed that Lada 2107 from 1986 had Solex carb. It is called Daaz Solex. It looks a lot like the 28-34 Z10. What do you think, is it the same carb? would parts from that carb fit this? Because we got a Lada dealer here in Finland. The carb is this:


They have really cheap parts for these carbs.


Repair kit:

They also have the washer plate between carb and intake manifold.

Re: Volvo 340 1.7 splutters and cuts out

Posted: 08 Jan 2020 06:01 pm
by blackVolvo
So my mechanic has now assessed the situation. carb base is warped 0.5 mm. Is it still salvageable? he recommended putting some sealant on the base, and new gasket ( sealant which lasts in hot and oily/gasoline environment). Also intake/exhaust gasket was finished. He will also change motor, transmission and diff oil. Also he said that inside blower cuts out intermittently.

Re: Volvo 340 1.7 splutters and cuts out

Posted: 09 Jan 2020 05:01 pm
by blackVolvo
So my mechanic change carb seal, intake seal, new ignition parts, and all oils. But after engine warms up, it starts to cut out :(.

He made a video of the problem:

So waht to do now, any thoughts? Is the intake/exhaust manifold completely gone? And if so, any1 here have a replacement, which is ok?

Re: Volvo 340 1.7 splutters and cuts out

Posted: 10 Jan 2020 07:20 pm
by Benparker
As an update and hopefully and end to this thread, after checking the fuel pipes at both ends of the car, i found the original fabric coated pipes at the tank unions. Once these had been changed i have had no more running issues. Cheers guys for all the helpful pointers!

Re: Volvo 340 1.7 splutters and cuts out

Posted: 11 Jan 2020 09:37 pm
by bogbasic
Since the heater blower motor is cutting out, you need to get one of these as a part-exchange of your old unit. Its a bimetallic thermal cutout which is a very common fault. ... g%20system

That will sort it.

Re: Volvo 340 1.7 splutters and cuts out

Posted: 13 Jan 2020 09:17 am
by blackVolvo
Update on the situation.

The carb base has now been machined to be ass straight as possible. The intake manifold had warping less than 2 hundreds of millimeter, so that does not need straightening.

My mate put the thing together and...same problem. Now it does not change rpm when spraying with water or bräkleen. So we have now eliminated vacuum leaks on cab.

My mate said that they tried to run without gas tank lid, as to exlcude problem that gas tank is not getting replacement air. That did not help also.

They said that when the problem occurs, tapping the carb cures the problem for a while. So he said that it seems that the carb float bowl has problem. He said that it seems that when bowl is empty, the needle valve does not open. And that leads to running lean and engine dying. After knocking the carb, float opens, and carb gets fuel. Until it closes again and does not open, and engine dies.

Does any1 here have new/replacement float and needle (do I need a new needle "base" too) for fixing this problem for good?

Re: Volvo 340 1.7 splutters and cuts out

Posted: 13 Jan 2020 11:10 pm
by bogbasic
I gather that the floats become permeable and sink in the float chamber. I would contact Born Built Beauties by e-mail and he will put you in touch with MAC. I don't know about the needles sticking in Volvo's but it definitely happens with SU carbs that have rubber-tipped needles!!

Re: Volvo 340 1.7 splutters and cuts out

Posted: 16 Jan 2020 07:08 am
by blackVolvo
Update again.

So with macs help, i got the replacement parts for the carburettor. Parts from DAAZ Solex did fit the carb. Now it has new float, float valve and diaphgrams.

Unfortunately it did not help. Same problem occurs. But now the carb has petrol in it, it is confirmed.

Could this be a ignition problem after all? Maybe after engine gets to temp, something in the ignition stops working, and the engine loses spark. And after it cools down a bit, it works again? Had a Opel Corsa in the 90s that had same kind of problem, and the distributor in that car started to "leak" the spark, when it warmed up. Really annoying to find that problem.

Is here a guide on how to measure the ignition parts and reference values on cold and hot engine? Distributor cap, rotor and leads are new.

Re: Volvo 340 1.7 splutters and cuts out

Posted: 21 Jan 2020 07:05 pm
by blackVolvo
Last update hopefully.

After trying everything ( found 3 used renix units and 1 crankshaft sensor in the boot) I opened the fuel tank. The filter on bottom of the fuel suction line seemed fine until I tried to run water through it. It barely got out, took like 30 seconds for water to drop at half level. So took the filter out because I don't know where I could find a new one. Result-> car works like there never was any problem with it. It revs like it should, never hesitates. Have driven 15 km now.

Does anyone have a link where to get the filter or volvo part number? Or should I just leave this as it is?

BTW one of the renix unit is kaput (the original 415) it has now 408 installed, hope that won't cause any problems? the other two units I could sell.