Engine: 2.3 F/Inj B23E/B230F: Starting Problems

[Clifford Pope]

240 SE 1991, with LH 2.4 fuel injection

Without much warning the car suddenly refused to start one morning. After prolonged cranking and a lot of spluttering and misfiring it did start, in a very hesitant kind of way, and gradually picked up, with a lot of smoke from the exhaust. It then ran all right, behaved perfectly, restarted at the shops, and got back home.
Next time, it did the same thing but wouldn't start.

I worked through my usual list:
Fuses, especially 4 and 6 - no difference
Bridged 4 and 6 to run the fuel pumps - no difference
Swapped Ignition Amplifier Module for a known good one - no difference
Swapped Crank Position Sensor for a known good one - no difference

General clean up of HT leads, coil, checked distributor cap for condensation, etc produced no joy.
By now the battery was flat, so I charged it up, and the engine then fired and ran for a while, but a bit shakily. Then suddenly it cut out and refused to restart.
I then remembered spark plugs as a possibility. They looked OK, a bit sooty from recent failed starts and misfires, had done about 10,000 miles. Putting in new ones made no difference, except that the car banged and backfired but wouldn't start.

At this point I rang a local mobile diagnostician, and he said before coming out he needed to do a bit of research, as he hasn't done a 240 for a long time. He rang back the next day (this was Christmas) to suggest the following:

Even though the rotor arm is quite new, they can fail. It would be worth replacing.

Likewise the distributor can track, especially after a spell of very wet wheather such as we had recently

Suspect the coil - they can break down over time. I was not sure about this - it was relatively new, and a proper Bosch.

The main thing he recommended was checking the earths. I've been aware of this, but never knew exactly where to look. He remembered a vital point on the inner wing hidden behind the battery, and this did indeed look grey and rusty, with a corroded bolt and washer.
I had always assumed that the engine and all components on it were earthed by the very substantial cable fastened to the block just by the left-handengine mounting. But that is not true. That cable does not earth the electrical components running off the engine, it ensures that the starter motor has a good connection to battery negative.
That apparently is not the same thing as earthing the block, hence the braided wire between the valve cover and the bulkhead. This too was corroded at the bulkhead bolt.

Anyway, and attending to all these points the engine sprang into life and ran more smoothly than it has for some time. Things must have been slowly deteriorating for some time.

Another point he made was sometimes it is the totality of substandard components and connections that can suddenly cause starting problems, often triggered by damp air. One alone might not be that serious.
This of course makes diagnosis difficult, and is a flaw in the method of testing by substitution.

I just thought this might be of use to someone.



PS he didn't charge anything

[Stephen Edwin]

Thank you Clifford.

The symptoms you describe are a little different but not a million miles different from the starting troubles I posted about last year. The problems have not happened again and I have not yet investigated further.

I shall in any event check the earthing....but I hope to wait until the warmth of the Sun returns to this hemisphere.



P.S. That diagnostician took trouble to advise carefully. They are a person to remember, and to recommend to people in their area init?

Anyway maybe name them in the forum for any member in or near their area?


.



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[Clifford Pope]

Certainly - he's Gary at Car Fix Wales, in Cardigan.


Another point re the new rotor arm, from Classicswede. Someone else reported problems with them not fitting, despite being the right part number.
I found the plastic had a slight casting burr, just a tiny projecting flake, but it jammed and stopped the arm pushing on. It needed very gentle easing with a small file or a sharp knife.
Another point is to emery the metal shaft so that the arm presses right down to the bottom. It is a very tight fit, unlike some makes which are a bit wobbly.

[BrianH]

If you have an E engine they have an amplifier behind the radiator and in front of the battery. This has a multiplug connection with a rubber boot. A good wiggle got me out of trouble in Devizes last month.


The coil got me on the Autobahn after 18 years. As I was off to Venice at the time and the coil is quite heavy it was off loaded after I had carried around for years.


The Volvo Garage charged me 15 Euros for the used coil from a 740 and spending an hour with two engineers to find the problem. I like Europe. Though it cost me 130 Euros to get 15kl to the garage.


BrianH 245 230E LPG 700 000 mls.

[Dirty Rooster]

Originally Posted by Clifford Pope

The main thing he recommended was checking the earths. I've been aware of this, but never knew exactly where to look. He remembered a vital point on the inner wing hidden behind the battery, and this did indeed look grey and rusty, with a corroded bolt and washer.
I had always assumed that the engine and all components on it were earthed by the very substantial cable fastened to the block just by the left-handengine mounting. But that is not true. That cable does not earth the electrical components running off the engine, it ensures that the starter motor has a good connection to battery negative.
That apparently is not the same thing as earthing the block, hence the braided wire between the valve cover and the bulkhead. This too was corroded at the bulkhead bolt.

Anyway, and attending to all these points the engine sprang into life and ran more smoothly than it has for some time.

Good information,
the earths always seem to be the last thing to check,
I guess on some cars they never give trouble for the whole life of the car.

[Clifford Pope]

Another point I'm unsure about is the exact naure of the mounting of the Ignition Amplifier Module next to the left-hand headlamp, in front of the battery.

I have always understood that the module itself is the black moulded plastic plate, and that the hefty alloy plate it is screwed to is a heat sink.

Is it also earthed through the contact with the plate, and then via the two small screws onto the wing? I presume not, because when testing for a possible failure at the roadside a good IAM will work even if just dangling on its heatsink and cable, disconnected from the bodywork.

The alloy plate has a flat polished surface, and the plastic module has a polished metal plate too. Corrosion in between obviously breaks down the heat contact, but also I was once told by another ignition diagnostician, distorts the module and causes internal faults. On his advice therefore I have always put special electrical contact grease between the two faces.

As a precaution I have bought a new module, to replace or at least keep handy in the car. I was about to screw it onto a spare heatsink in readiness but am puzzled by the sealed plastic pack in the box, of what appears to be a dry white powder. There are no instructions. It seems hard to believe one is meant to mix it into a paste with water to apply between the surfaces, but what else is it for?

Also, the polished plate on the module is not perfectly smooth, like all previous ones I have seen, but has 4 tiny pinpricks sticking out, like tiny stylus needles. Placing the module on the heatsink means there is a tiny gap - it doesn't lie flat because of the pins.
Should I screw the module down hard, to squash the pins into the softer alloy? Is that a clever way of getting a good contact?

I don't get it - that might perhaps make a good earth, but hardly good heat conduction, surely? Heat conduction surely needs the highest flat contact, not sitting on 4 tiny high spots?

[Stephen Edwin]

Originally Posted by Clifford Pope

Another point I'm unsure about is the exact naure of the mounting of the Ignition Amplifier Module next to the left-hand headlamp, in front of the battery.

I have always understood that the module itself is the black moulded plastic plate, and that the hefty alloy plate it is screwed to is a heat sink.

Is it also earthed through the contact with the plate, and then via the two small screws onto the wing? I presume not, because when testing for a possible failure at the roadside a good IAM will work even if just dangling on its heatsink and cable, disconnected from the bodywork.

The alloy plate has a flat polished surface, and the plastic module has a polished metal plate too. Corrosion in between obviously breaks down the heat contact, but also I was once told by another ignition diagnostician, distorts the module and causes internal faults. On his advice therefore I have always put special electrical contact grease between the two faces.

As a precaution I have bought a new module, to replace or at least keep handy in the car. I was about to screw it onto a spare heatsink in readiness but am puzzled by the sealed plastic pack in the box, of what appears to be a dry white powder. There are no instructions. It seems hard to believe one is meant to mix it into a paste with water to apply between the surfaces, but what else is it for?

Also, the polished plate on the module is not perfectly smooth, like all previous ones I have seen, but has 4 tiny pinpricks sticking out, like tiny stylus needles. Placing the module on the heatsink means there is a tiny gap - it doesn't lie flat because of the pins.
Should I screw the module down hard, to squash the pins into the softer alloy? Is that a clever way of getting a good contact?

I don't get it - that might perhaps make a good earth, but hardly good heat conduction, surely? Heat conduction surely needs the highest flat contact, not sitting on 4 tiny high spots?

This is interesting Clifford. From what I've read in the forum, one cleans the heat sink and uses mounting paste, the stuff used in electronics? The correct term escapes my remnant of a grey cell.

What make is the module you have bought, where from and to be really nosey, how much did you pay please? I perhaps would not have great confidence in it.


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[Clifford Pope]

"Professional Parts - Sweden" supplied by Charlton Volvo, £24.99.

I got the other bits from Brookhouse, but they didn't seem to list the IAM.

[Stephen Edwin]

Clifford I'm cogitating the point about the engine, and components, being earther via the two connections you have told us about.

Various things such as Air Mass Meter and as you point out the ignition amplifier, are connected to earth via their multi-pin connections.

Some of those earth connections must go via the engine and depend on those two connections you have told us about.

Cleaning up those two connections has just become rather high on my list of jobs, when the sun returns to this hemisphere.

[Clifford Pope]

Yes, I agree. I've never properly understood the concept of "earth" - it doesn't seem to be as simple as just connecting all the negative sides of all the circuits and then connecting them to the chassis and to the battery negative.

It seems different components use a different basis as "earth", and that problems can arise if a circuit tries to complete through the wrong one because of poor connection in its designated earth.
On the other hand I've encountered in hi-fi the existence of "earth loops", where weird things happen if linked components are each earthed at too many points.

But in our case, hiding a vital earth point behind the battery is a recipe for it's being overlooked and quietly corroding.

I wonder whether there are any other such points? Does the ECU for example behind the driver's door pillar have an earth point? I've never looked, but water ingress at that point is perhaps highly likely, in view of the well-known vulnerability of the fuse box on the other side.

Does anyone have a diagram of the location of all earth points?