240 - Won't idle on cold start - LPG - carburetor.

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Harvey Birdman
Posts: 10
Joined: Fri Feb 26, 2010 7:23 am
Year and Model: 240 1983
Location: Australia

240 - Won't idle on cold start - LPG - carburetor.

Postby Harvey Birdman » Fri Feb 26, 2010 3:20 pm

Greetings from down under.

Ok I've got a 1983 manual wagon running on LPG with a B230E engine, Solex 175CD carburetor (no fuel injection) .

Just lately it's been getting difficult to start and running a little unevenly. I replaced the plugs... didn't make much difference.

Now it's got to the point when I start it, I can't get it to idle. In the last week when I try to start it, choke out, it eventually fires and runs for one or two second and then dies.

The only way around this is to pull the choke all the way out and as soon as it fires, flatten the accelerator and keep it revving at around 3k until it warms up.

Once it's warmed up and been driven for 15 minutes I can switch it off and leave it for an hour and start it without a problem.

Keep in mind that I live in a very temperate climate 15 - 30 C. Quite warm.

I've had 240's for the last 20 years but never one that ran on LPG.

Any help would be much appreciated. Thanks in advance.

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billofdurham
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Posts: 6508
Joined: Thu Feb 02, 2006 10:31 pm
Year and Model: 855, 1995
Location: Durham, England

Re: 240 - Won't idle on cold start - LPG - carburetor.

Postby billofdurham » Fri Feb 26, 2010 6:36 pm

Welcome to Matthew's Volvo Site.

LPG - not many of them appear on this forum. However, my son has an LPG powered Talbot Express motorhome and I am playing with an LPG powered Jeep Grand Cherokee as well as my Volvo. Between us we should be able to work something out.

Do you always start on petrol or can you start on LPG? When my son bought his carb version he was told by the converter that he would find it easier to start on petrol then switch to LPG. We later found out, from a different converter, that if the system is set up correctly it can be started on LPG. His vehicle has been unused for about two months, as winter isn't the time to be going out with a motorhome. Last week we started it up, in freezing temperatures, on LPG and it ran like a dream. He hasn't had it switched to petrol for over 2 years now. That ramble was to clarify the reason for my question.

If your problem is only when running on petrol then it is a carb fault. If it is only when running on LPG it is an LPG system fault. If it is on both it is probably an engine fault.

Post back so I can dig deeper.

Bill.
Work was good - retirement is better.

1996 850GLT 2.5 20v Estate Manual.
1995 Peugeot Boxer 2.5Tdi Autosleeper.
Previously:
1984 244DL, Manual, Beige.
1987 744GLE, Manual, Green.
1991 960 3.0 24v, Auto, Silver.
1994 940T Wentworth, Auto, Blue.

Harvey Birdman
Posts: 10
Joined: Fri Feb 26, 2010 7:23 am
Year and Model: 240 1983
Location: Australia

Re: 240 - Won't idle on cold start - LPG - carburetor.

Postby Harvey Birdman » Sat Feb 27, 2010 3:02 am

Hi Bill

Thanks for taking the time to reply. As we are on totally different time zones the replies might be about 12 hours out of sync.

OK this one is set up to run on either LPG or petrol. It has never run very smoothly on petrol, keeps wanting to stall.

I always start it on LPG, Always run it on LPG. Petrol just there as a backup. Plus it's difficult to start it on petrol. The previous owner advised me to run it on petrol just for a few minutes every couple of weeks... something about lubrication.

As far as I know the carb is used for both petrol and LPG. There's a 3 position switch on the dash that switches between the two. The centre position is used when changing from petrol to LPG. The idea is that the petrol supply is stopped and you run out what's left in the bowl before switching to the LPG position. As soon as the engine starts to stall you switch to the LPG position.

I think there must be a couple of solenoid valves that allow either LPG or petrol to flow into the carby depending on which position the switch is in. So I guess when the switch is in the centre position both LPG and petrol supply are stopped.

The starting problem is only when it's cold and becomes worse the longer the car isn't used. Sometimes it only gets used once or twice a week. The LPG is great for economy but there is a small loss in power but that doesn't bother me.

My feeling is it might be the carb but that's only based on the Haynes Workshop Manual fault diagnosis for petrol.

Looking forward to your reply.

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billofdurham
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Joined: Thu Feb 02, 2006 10:31 pm
Year and Model: 855, 1995
Location: Durham, England

Re: 240 - Won't idle on cold start - LPG - carburetor.

Postby billofdurham » Sat Feb 27, 2010 6:16 pm

That is the correct way to use the LPG system and you are correct in thinking the carb is used for both LPG and petrol. If you remove the air filter box you will see an extra part has been added to the carb body. That is the LPG inlet.

Re-reading your first post I see "when I try to start it, choke out". Does this mean that you are pulling the choke out to start on LPG? The choke is only needed to start on petrol. To start on LPG switch on the ignition for about 1 second, switch off, switch on again for about 1 second and turn to start position. If the engine doesn't fire up repeat the above until it does. When my son started his last week it required four double 'sniffs' of LPG, after two months standing and in freezing conditions.

The previous owner advised me to run it on petrol just for a few minutes every couple of weeks... something about lubrication.

He is correct and my son has pointed out that he does this regularly. If you run constantly on LPG the seals in the carb will dry out causing problems if you need to run on petrol. He does his petrol run for about 10 minutes every other week when he is using the motorhome.

How long is it since a gas service was done? It is recommended that it be done every year. Like anything with an ECU, settings can go off and some LPG systems have filters in the lines which need to be changed. I saw the filters taken out of my son's van after 3 years of use. They were, to be polite, extremely dirty. He had used his van for the 3 years not knowing the LPG system needed to be serviced. After the service he was amazed at the extra power and increased economy on a run that he makes at least four times a year. His annual LPG service is booked for next week before he hits the road for Scotland again.

As a matter of interest for other members who may read this the fuel injected LPG system always starts on petrol and switches to LPG automatically at a preset RPM. My Jeep is set at 1,400rpm. It can, of course, be run totally on petrol but the changeover switch only has two positions as opposed to three on the carb version.

Bill.
Work was good - retirement is better.

1996 850GLT 2.5 20v Estate Manual.
1995 Peugeot Boxer 2.5Tdi Autosleeper.
Previously:
1984 244DL, Manual, Beige.
1987 744GLE, Manual, Green.
1991 960 3.0 24v, Auto, Silver.
1994 940T Wentworth, Auto, Blue.

Harvey Birdman
Posts: 10
Joined: Fri Feb 26, 2010 7:23 am
Year and Model: 240 1983
Location: Australia

Re: 240 - Won't idle on cold start - LPG - carburetor.

Postby Harvey Birdman » Wed Mar 03, 2010 11:30 am

Hi Bill, sorry for the delay, the rain been hammering down the last few days and I don't have a garage. Previous owner instructed me to use the choke to start it and on the occasion when I forgot to pull out the choke it wouldn't idle unless it was a very hot day. Tried priming it with the ignition switch as you suggested but no luck. LPG was serviced a year ago. Also when I was looking on the engine block I noticed that it's stamped B230F but on the timing belt cover it has B230E.

So here's what I did today.

1. Cleaned all the electrical connections.

2. Took the distributor cap off and cleaned the rotor and the contact points inside the cap. After looking at the Haynes manual I thin this is a breakerless distributor.

3 Took the top off the carby and inspected the rubber diaphram... seems quite pliable without any fractures.Noticed there was no fluid in the centre chamber so I added some ATF. Put that back together.

4 Got my wife to crank it and checked for a spark... orange spark jumping about 6mm (1/4")

5. Turn on ignition and I can hear LPG supply solenoid on the tank working

6. Flicked the LPG - Petrol switch up and down... could hear the changeover solenoid near the carby working.

But still it won't start.

Now I've got a background in electronics but my Dad when he was alive was a mechanic so I know a few things I picked up from him and I'm pretty good at fault finding. One of my first Volvo's was a carburetor model, 1976DL and had a similar problem. I remember my Dad pouring some petrol down the carby and got it to kick over. So with that in mind I had a look at this Solex 175CD carb but can't see any way of getting any petrol into it... any suggestions on that front. I just like to rule the carby out of the equation. I'm loathed to play around with the LPG as I know nothing about that.

Now I noticed on the forum that there is talk of a faulty Air Mass Meter stopping the car from starting and if unplugged will allow the the car to start but idle roughly. So my question is does this 83 carburetor model have an AMM and if so where do I find it so I can unplug it?

Lastly if I'm getting a spark at the plugs does that mean the ignition control unit is working?

I also take some photos of the engine bay tomorrow and post them as it might help.

Sorry for all the questions.

Thanks again

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billofdurham
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Joined: Thu Feb 02, 2006 10:31 pm
Year and Model: 855, 1995
Location: Durham, England

Re: 240 - Won't idle on cold start - LPG - carburetor.

Postby billofdurham » Wed Mar 03, 2010 7:56 pm

Now I am confused. Breaking down the code B230F shows B = petrol: 23 = 2.3 litre; 0 = low friction block; F = injection with Lambda and catalyser. B230E is the same except for E = injection without Lambda and catalyser.

The 1983 240 did not have a B230F/E engine. I can only assume that someone has replaced the block but used the original head with the carb. The timing belt covers are identical so that is probably a used replacement.

Re point 4. The spark should be blue not orange which could be a bad plug lead or the ignition coil starting to fail. You can check the coil with an ohmmeter. Primary resistance is measured over the two low tension connectors (1 & 15) and should be between 1.1 and 1.3 ohms. Secondary resistance is checked using terminal 1 and the high tension tower and should be between 9,600 and 11,600 ohms.

The Solex carb makes it awkward to pour petrol in but if you remove the air filter hose from the carb you can spray Easy Start or similar into the carb and it should start on that.

There is no air mass meter on a carb engine.

Bill.
Work was good - retirement is better.

1996 850GLT 2.5 20v Estate Manual.
1995 Peugeot Boxer 2.5Tdi Autosleeper.
Previously:
1984 244DL, Manual, Beige.
1987 744GLE, Manual, Green.
1991 960 3.0 24v, Auto, Silver.
1994 940T Wentworth, Auto, Blue.

Harvey Birdman
Posts: 10
Joined: Fri Feb 26, 2010 7:23 am
Year and Model: 240 1983
Location: Australia

Re: 240 - Won't idle on cold start - LPG - carburetor.

Postby Harvey Birdman » Wed Mar 03, 2010 9:40 pm

Thanks Bill

I'll try all those suggestions today and let you know what happens.

Do you know if the spark plug gap is the same for LPG. I put a new set of plugs in a few weeks ago when idling started to play up but didn't seem to make any difference... Bosch W6 DC-18 Copper core, resistor type 0.7mm

Yes I think it's definitely had the engine changed. A lot of things don't match up with the Haynes Manual. It's not an Australian model, it was actually brought out from the UK by the original owner. I also think the wiring has been modified.

In reference to the coil, how many connections should there be to the primary connectors? There's a black wire hanging just below the coil with the other end just behind the distributor near the block, neither end connected. There is a spare terminal on the primary of the coil but I can't find anything near the other end that it might have been connected to... I think it maybe an old wire that may have been replaced at some time.

I'll take some photos today and post them.

Thanks

Harvey Birdman
Posts: 10
Joined: Fri Feb 26, 2010 7:23 am
Year and Model: 240 1983
Location: Australia

Re: 240 - Won't idle on cold start - LPG - carburetor.

Postby Harvey Birdman » Fri Mar 05, 2010 6:31 pm

Hi Bill

Here's some info about the ignition system I measured, starting with the coil.

Primary: 1.91 ohms
According to the Haynes manual this is within spec for a breakerless ignition.
Secondary: 9.6k ohms

Coil to distributor lead: 9.2k ohms

Distributor to Plug 1: 10.3k
Distributor to Plug 2: 8.2k
Distributor to Plug 3: 8.3k
Distributor to Plug 4: 8.1k

I tried another coil with it but it didn't make any difference. Still getting an orange spark at the end of the coil lead and at the end of the plug leads. The other coil was from my previous 85 model. I checked it's windings and they matched the figure you gave me.

Would the control unit have anything to do with the strength of the spark? Will I still get a spark if I disconnect it?
Control Unit: 0227 100 018

Is there any other reason I 'm not getting a blue spark from the coil. What voltage should I see across the primary?

Also noticed when I tried to start it on petrol I couldn't hear the fuel pump, so I tried running a jumper from fuse 5 to 7 but still couldn't hear the fuel pump. I'll check that tomorrow.

I bought some easy start so I'll try that. Could I spray it into the manifold by taking the tube from the distributor off and spraying it in there??? Just thinking ahead in case it doesn't work when I spray it in the air intake.

Sorry for all the questions.

Thanks

User avatar
billofdurham
MVS Moderator
Posts: 6508
Joined: Thu Feb 02, 2006 10:31 pm
Year and Model: 855, 1995
Location: Durham, England

Re: 240 - Won't idle on cold start - LPG - carburetor.

Postby billofdurham » Fri Mar 05, 2010 7:23 pm

Is there any other reason I 'm not getting a blue spark from the coil?

I am not an electronics expert but I think your plug leads have too high a resistance. Volvo specs for your model and year are 4,600 to 6,600 ohms per 3 feet of wire. As you have an electronics background you can tell me if my assumption is correct. I love to learn.

I bought some easy start so I'll try that. Could I spray it into the manifold by taking the tube from the distributor off and spraying it in there???

Using a spray tube in the nozzle should get it in there.

Don't disconnect the control unit as it won't improve matters.

I have had a chat with the local LPG converters about the choke. On a down draught carb, as fiited to my son's motor home, the choke would block the flow of the LPG. On a Solex they don't think it will make any difference to the flow but they say it won't help to start the engine on LPG.

Bill.
Work was good - retirement is better.

1996 850GLT 2.5 20v Estate Manual.
1995 Peugeot Boxer 2.5Tdi Autosleeper.
Previously:
1984 244DL, Manual, Beige.
1987 744GLE, Manual, Green.
1991 960 3.0 24v, Auto, Silver.
1994 940T Wentworth, Auto, Blue.

Harvey Birdman
Posts: 10
Joined: Fri Feb 26, 2010 7:23 am
Year and Model: 240 1983
Location: Australia

Re: 240 - Won't idle on cold start - LPG - carburetor.

Postby Harvey Birdman » Fri Mar 05, 2010 8:08 pm

Hi Bill

I did try another set of leads that had a much lower resistance, between 1 & 2k but didn't make any difference.

I'm going to pull the rotor, distributor cap and leads of my other 240 tomorrow and try them. This ones an fuel injected auto and only runs on petrol. It starts as soon as you turn the ignition so I figure it's worth a try.

Have look at the link below and tell me if you know what the circled device is, One side comes from the fuel pump and the other side goes to the petrol control solenoid.

http://www.glowfoto.com/static_image/05 ... 5/glowfoto

Thanks again


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