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Hello. Have a strange problem that is really stumping me, hoping someone can provide some insight. First, a quick history,
Last week, my battery took a crap. car wouldnt start unless I jumped it. The battery was really old, so I got a new one. Car ran good for 2 or 3 days, then needed a jump. Led me to believe the alternator was actually bad. The car would start and drive with a jump, but the lights were really dim, the car would stumble and stutter, and actually die if I used the turn signals or turned the fan on. It would also smell like gas, I think due to not enough juice from the alt to get a good spark/complete burn. After 2 days of limping to work and back, I discovered that my alt bushings were shot, and the alt was barely making contact with the belt, and barely spinning. So, I ordered some bushings from IPD. Unfortunatly, I had to keep driving the car to work while I waited on them, so a couple more days of no-headlight stuttering crappy running driving were neccesary. I figured I would need to clean/replace my plugs when I got the alt squared away, due to the incomplete burn issue fouling them out.
Fast foward a couple days. Got the bushings in, got new alt belts, cleaned plugs real good, re gapped them. Car has new cap/rotor/plug wires. But, still has a horrible stumble/misfire. While the car was running, I pulled off the plug wires one at a time, to see which one didnt make change the lumpy idle. First plug, car fell on its face. Second plug, the idle actually rose a little and smoothed out. Third plug, same thing, smoother idle. 4th plug, car fell on its face. I can feel a very slight shock when handling the middle two plugs, and see a very faint arc jumping from the boot the the plug. I even tried switching the middle 2 plug wires around, and the car actually runs better (but not good), with the firing order messed up!
So, it seems to me that the timing is somehow WAY off, or there is a big vaccum leak somewhere. What controls the timing on these cars? how would it get that far off? I will continue to hunt for a vaccuum leak, but thought I would ask for some other ideas.
Sorry for the long story, but thanks for reading!
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posted by
someone claiming to be John McPhail
on
Sat Sep 22 18:09 CST 2012 [ RELATED]
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I was convinced that this was an ignition problem until you posted about the car idling fine but dying when you tried to accelerate. This is a 'classic' symptom of a bad air mass meter. With the ignition OFF, disconnect the wire to the air mass meter and start the car. You won't be able to drive over about 2500 rpm in any gear and the car will run extremely rich ("limp home mode"), but if it is drivable with the AMM disconnected, that is your problem.
A bad in-tank pump would not cause these symptoms. In fact, it often happens that you do not know your in-tank pump is dead until the main pump under the car starts buzzing (because it's been doing double duty for the last who-knows-how-long and is itself in the early stages of failure).
A bad fuel pump relay, or bad ECU, would cause the fuel pumps not to run at all. Your car would not start.
As others have suggested, it probably would not hurt to replace the wires, cap and rotor if they are of an unknown age. I would also take a look at the timing belt.
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I am pretty certain that the intermittent no acceleration thing has something to do with the in tank pump or this bellows hose thing I keep reading about. When it was doing that, the car was under 1/4 tank. Filled it up, and it runs great now, for a 3 cylinder with an extra piston flopping around.
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Yup, running poorly with a 1/4 tank or less is a classic symptom of a bad in-tank fuel pump. Have you opened the gas cap door when the car is idling and listened (use a stethoscope or hose) for the whirring sound of the pump running? Silence means you need a new pump...:)
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There can me numerous issues with the 84 240 especially with the ignition and wiring harness, Bad wires can do all sorts of flaky things.
I just got through ripping the wiring harness out of my '84 and repaired the bad wires. Most common failures are the black, brown and red wires coming from the alt red exciter wire, power wire to the Ing unit, oil pump sender wire and coil neg brown wire, not to mention the lighting and accessory block, but the scarriest thing is the wires that the insulation degrades is usually inside the harness and shorts out to other wires, an these can get completely free of their insulation. If a drop in voltage or increased resistance from the coil to the ECU pin #1 happens the fuel pumps won't trun on and you will get a no-start or intermittent rough start. Ground the ground side of the Fuel Pump relay, (85) the first silver cube one, (they are both the same realy, and the other one is the system relay). If the pumps run and car starts fine then look to the wiring.
Check the resistance of each wire at the main connector on the firewall and at the ign unit. There is also a vacuum line that goes to the ign unit from the intake manifold , around the distributor, below the engine and over to teh black box on the passenger side and can cause poor running if it's broken or leaks.
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First off, it doesn't sound like a timing issue, but needs new wires.
What model/engine/trim is the car??? Transmission?
This makes a big difference diagnosing an '84 240
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Yes, sounds like bad wires. There may be arcing between 2 and 3 causing the bad idle.
In the dark, look for arcing. Spray water on the wires to see if things get even worse.
You could lift the distributor and reposition it so that it matches Lucid's picture. There's a faint notch on the distributor rim (like the faint timing notch on the crank pulley) which lines up with the rotor when timing is set at Top Dead Center.
--
1980 245 Canadian B21A with SU carb but electronic ignition and M46 trans in Brampton, Ont.
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I agree. Sounds like a bad wire or wires.
Didn't you say you replaced the wires? How new are they? Double-check the connectors to make sure they are clicked in properly to the plugs. Check the distributor end connections too. Look for damage on both ends.
Perhaps you crossed wires when you cleaned the plugs?
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Sorry, this is my first volvo, so not super familiar with them. I thihk its a B23? Its a non-turbo, electronic injection, m46 tranny. And i am going to swap around the wires today, see if the problem follows one or more wires.
Thanks
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Thanks for that picture. My firing order/routing is correct, I have checked about a dozen times. however, comparing my car to that picture, my dist is rotated 90 degress counter clockwise, so that 1 and 2 are both facing foward.
I also put my meter on the coil and plug wires. Plug wires all check out good, about 5k ohm each. The coil measures 1.3 ohm from the + to the -, and 8.4k from the + to the post. This seems ~roughly in spec to what I can find on general coil testing, although the + to - reading seems high. Does anyone have the OE coil specs?
Also, there is a small vaccum line that runs from a check valve on the intake manifold, opposite of the throtttle body, that runs into the firewall. You can see the check valve in the above pic. What is this for? cruise control? My car doesnt have CC, and that hose was torn to hell, so I capped it off at the manifold. Problem?
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"My firing order/routing is correct, I have checked about a dozen times. however, comparing my car to that picture, my dist is rotated 90 degress counter clockwise, so that 1 and 2 are both facing foward."
Maybe a previous owner repositioned (re-meshed drive gear) to compensate for a maladjusted timing belt. It's also possible that the timing belt stripped a few teeth if worn and oil soaked.
In any case, I would start by checking the basic timing. Pull all 4 plugs for easier turning (22mm or 7/8" wrench on crank pulley bolt).
1. Turn crank to Top Dead Center (TDC) on the compression stroke, per timing mark on crank pulley. Put a finger on #1 plug hole to verify compression stroke. (pulley mark also lines up at 0° on exhaust stroke)
2. Check that camshaft drive sprocket mark is at 0° (remove cover screw and pull cover forward to see marks).
3. Check that distributor rotor is pointing at the #1 wire tower.
Ignore the check valve for now (no pic came thru) as long as the hose is capped off.
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
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I checked the cam timing, and even though its different from that pic, its correct on my car. I dont know why the the pic is different.
It has developed a new problem... Im unsure if its related or not.
The car runs and drives, but only on 3 cylinders so its rough and has no power. After about 5 minutes of driving, the car will bog down and lose all power. it will idle, but if you give it any gas at all, it fall on its face. I will have to pull over, and after a few minutes of attempting to give it a little gas, and waiting, it will eventually pick back up and I can drive again for another 5 minutes or so. To me, this sounds like a fuel issue. This car has 2 fuel pumps, correct? does it also have 2 fuel relays? I was checking the fuel pump relay, and got a little confused as to what was what under the passenger kickboard. I have 2 small silver relays, and one big blue one. I pulled the small silver ones to do my compression test, and they acted like fuel pump relays. Whatever the big blue on is, it does not come on with the key.
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