This problem has occurred since last November. The distributor cap fouls every hour or so of running. It’s a greenish white color, I scrape the contacts and I’m good to go, for about an hour.

Last November I cleaned the engine bay, then I changed the plugs, distributor cap, and rotor. Changed the fuel filter and had to replace some of the fuel hose near the filter. I drove with no problem from Seattle to Redding, and even went through central Oregon, so about 900 miles. After getting down into the valley my car died. I fiddled with the fuel line and noticed it was kinked a bit where I had spliced it. Car cooled down and I was able to drive it to San Diego with little power and only being able to compress the gas peddle about 5-10%, otherwise car would bog down and die. I eventually popped the distributor cap and saw the contacts were all covered in white, which I thought was plastic from the end of the rotor. Now, I’ve been trying to figure out what’s causing this repeated fouling of the distributor cap, and driving the car as my daily driver since.

I’ve now replaced the cap and rotor three times, Bisch distributor cap.

Replaced and checked timing belt.
Spark plugs again.
New plug wires
New coil.

I thought maybe the timing was a bit off or that there’s an advance issue so I loosened the distributor and twisted counter clockwise a bit, test drove, still the cap fouls. I cleaned the contacts, twiste the distributor clockwise, cap still fouls. I set the distributor back where it originally was. I thought this might tell me if the hall sensor was causing the problem.

I called a Volvo mechanic today and he said he’s never seen this before.

Could the kinked fuel line or a bad filter cause the distributor cap to foul?

Is this a ground issue?

Crankshaft speed sensor?

Could it be the ecu?
The throttle switch?

I am to the point where this is gonna have to be resolved, I’m dumbfounded.

Any help would be greatly appreciated, I’m mechanically inclined but not too good with using electrical testers, but I also know throwing money at ecu and other sensors can get really expensive.
Thanks.

 

Year and model of the car would be helpful.

Where is contacts you are scraping? Are they inside the distributor cap or on the outside where the spark plug wires plug in?

 

sorry about that. It’s a 1985 244 DL with a manual transmission and the B230f

 

the contacts I scrape are inside the cap, the ones the rotor rotate inside of.

 

If you have a speed sensor picking up a signal on the flywheel - you do not have a hall sensor in the distributor - and twisting the distributor does not change the timing, it just makes the spark have to jump further from the rotor button to the contact points in the cap. I suggest making sure the distributor has been installed correctly. With the engine set to #1 (or #4) tdc, set the rotor button to line up with the the mark on the edge of the distributor, and tighten the distributor in that spot. Keep in mind crank dampers slip (the outer ring with the timing marks on it) so you might should use the cam timing marks to find tdc.

Engines with speed sensors have a wider contact area on the rotor buttons, Make sure you have the correct one - in cars with mechanical advance the rotor button automatically advances to the correct position in the cap, non- advance distributors stay at the fixed point so the spark has to jump over wider range, hence the larger area on that rotor button.

The distributor originally came with a plastic stop in the adjustment slot that would keep the distributor in the correct fixed position.

 

Well - it certainly rules out the Crankshaft Position Sensor since you don't have one. All your timing is set by positioning the distributor.

What brand of spark plugs and wires are you using? No way would I expect your fuel line to affect this (although your repairs sound a bit sketchy). Nor do I expect the ECU to affect this. Unfortunately I'm not familiar with the setup of the ignition system of this vintage (I owned post-'89 models only). I would stick to the ignition area as a cause.

How are all of your electrical connections. Keep in mind that as an '85 model your car is within the years that had the biodegradable wiring so all kinds of electrical gremlins can lurk in the engine harness.

 

I’m new to a lot of this, usually I have to stay between the coil and plugs. Brand new NGK plugs, I just removed the Bosch plugs from last year, no difference. I got the Napa plug wires, they are the “Belden Edge “ ones with the metal boots.

pretty sure my car has a hall sensor, it has a three pronged plug into a little mechanism on the side of the distributor

 

I can’t rule out electrical conections but the only corrosion I found was on the plug for the idle air control valve,. There’s been some rewirring on this car, and I can’t see any broken wires. I also ran it in the pitch black garage to look for any spark or groundings, no sparks at all were visible.
más for the distributor being put in wrong, I had the car for two years and never moved the distributor, and the car didn’t have this problem.

when I did the timing I used the mark on the crank shaft, not on the pulley, because the pulley on this one has slipped.

maybe someone else used the pulley mark then adjusted the timing elsewhere? But the belt seemed to be on correctly when I replaced it.

 

Yes - indeed you have the hall sensor system. Crankshaft speed sensor (better known as crankshaft position sensor or CPS) was introduced with the LH 2.4 fuel injection system starting in '89. In '85 they had an earlier version of the LH system (2.2?). It would be good to do some google searches and try to verify what components you have for your model (I believe yours has a Chrysler ignition system but I'm not an expert in your model year). Volvo used different components from different vendors over the years so it is important to familiarize yourself to what version is in your car.

 

Just read your year 1985 - no engine speed sensor and a pickup in the distributor.

"All covered in White, thought it was plastic" from the rotor - do you have the white cap and rotor on your car? If so that is the Chrysler system that was used for a short period of time.

From your description you are blaming the poor running and the stall on the distributor cap?

Is it possible you have a fuel pressure problem? The car dies/runs bad, then while you are futzing with the cap maybe the fuel pump cools down and can generate the appropriate pressure for a while, until it heats up again and you mess with the distributor cap allowing the pump to cool back down?

Or a heat related problem with the ignition system? On both the bosch and Chrysler ignition systems - there are problems with cracked solder joints on the circuit board of the ignition control unit. The black box mounted near the coolant reservoir with a vacuum line connected for the vacuum advance. These instructions are for that style control unit only. The pins for the multiprong connection - where they are soldered on the circuit board those connections crack - the board is covered in rubber, you can clean the rubber off in that area only and resolder the cracked solder joints. On the pin side there are sleeves that push onto the male pins, to tighten the connections. Make sure there is a sleeve on each pin . Google Volvo 1324909 for a picture of the sleeves.

 

yes, the 85 240 US models have the Chrysler ignition controller, this ICU is a black flat box on the right fender just behind the headlight. important features on this are A) a vacuum line from the intake manifold 'vacuum tree' to a bellows on the bottom of said ICU, and B) a rather fragile 6 (or maybe its 8?) pin electrical connector, which if improperly unplugged by rocking the plug will loosen up the pin sockets so they don't make good connections.

ICU connections:

1. Grey - timing output to Coil pin 1
2. Blue - power wire from Coil pin 15 and ignition key
3. Green - + from Hall sensor in distributor
4. N/C
5. Yellow - ground/shield from Hall Sensor '0' pin on distributor
6. Brown - knock sensor
7. Orange - full throttle switch on throttle body
8. Grey - timing signal to ECU

corrosion inside the distributor cap suggests moisture. A cap and rotor should last many years and many 10s of 1000s of miles without a glitch. question: is the dust shield intact and clean? this is under the rotor and helps seal the cap, and prevent arcing to the body of the distributor. I believe its Volvo part number 1336242 or 1389427 (the older parts catalog I'm using suggests 1985 240's might have had one of two different distributors, Bosch 0 237 506 001 or 0 986 237 631)... Its labeled 'condensation trap' on the Volvo parts catalogs.

 

Volvo only put those pin sleeves on a few of the pins, IIRC it was the ones that go to the hall sensor since thats such a low voltage/current level its sensitive to excess resistance

 

thanks for the theory but I don’t think it makes sense because I could drive until the bogging down occurs, not clean the distributor contacts, let it cool down and then the problem still exists until I clean the contacts. Also, I’m only turning the car off for about a minute and a half when I clean the contacts, and then it runs until the contacts are dirty again, about fifty miles of driving or so. I want to check fuel pressure but unfortunately this car doesn’t have the valve on the fuel rail that some have.

it could be heat related though, because if it’s cold out then it’ll run a while with the fouled cap. But if the car is hot and has a clean cap it runs fine.
I’ll look at those solder joints.

 

There ya no moisture in the distributor cap whatsoever. The plate under the rotor is intact. The corrosion is whitish green with a little black. I’m really thinking maybe the timing is off. I just took the timing belt off again about an hour ago. I believe the crank shaft was one tooth off, or retarded, meaning I twisted the crank shaft one tooth clockwise then reinstalled the belt. I can’t start the car until tomorrow though because I just put some gasket seal on the coolant system.

 

well, it pretty much takes moisture to make corrosion. do you live where its really humid ? if so, it could be condensation, which would be temperature sensitive.

I pulled the distributor cap off my 1948 Ford tractor the other day for the first time in like 8 years, and it was still quite clean inside, and this engine is totally exposed, and the tractor is parked on a field without rain coverage.

 

I'm sorry, but after working on these cars for over 40 years - you are focused/looking in the wrong place. (unless your upper hose is leaking coolant onto the distributor cap!)

 

so, to be clear, there is no moisture in the distributor cap. Maybe the contacts aren’t oxidized but have carbon build up from excessive heat. Whatever the case is, the contacts foul after about an hour of run time to the point that the car loses power. I lived in San Diego during October and November, very dry months, and am now in Seattle during the summer, also dry. I’ve owned 240s for ten years, this isn’t the typical moisture problem that occurs during winter, Ive experienced that before. Also, this car hasn’t leaked a drop of coolant the past three years until this week, and this distributor cap problem, or the problem that is manifesting itself in the cap has existed for 10 months, so it cannot be caused by a leaky hose.

 

You say the problem started last November.
Had you the car for a time before then without this happening?
Did it all start AFTER you cleaned the engine and replaced the ignition components?
If so, something you did at that time caused the problem, sure enough this is a head scratcher. You don't mention the ignition wires change at first, only later. I'd put some Bougicords in there, for the hell of it-- B230s seem to like them. It is a longshot but...

 

How about posting some pictures of the problem.

 

the car started and ran fine after I cleaned the engine bay, then I drove a thousand miles to Northern California with no issues.

I had the car for two years before this. Drove it to southern Mexico and back to Seattle.

i didn’t change the plug wires ten months ago, I changed them last week.

I’m starting to think maybe it’s that external fuel pump, I drove the car 300 miles yesterday delivering food, so I had to deal with this problem throughout the day. One thing I noticed is that the metal spindle the rotor goes on was quite oxidized, and I sanded it with Emory cloth, this made the car run better, longer, but the issue still exists. To drive 300 miles yesterday I probably cleaned the distributor cap ten times.
Maybe it is the fuel pump and with the contacts being just a little dirty the car loses power with low fuel pressure but if the cons ya are perfectly clean then it has enough power even with low fuel pressure. Idk. I’m thinking I’ll order a new pump and just install it to eliminate another possibility