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Two days ago:
Engine turned over normal speed then almost slowed to a stop before starting. Then ran rough for about 1/2 mile. Drove fine for rest of commute to work and back home (9 miles) no problem.
Yesterday:
Car did not start in the morning. Turned over at normal speed. Battery voltage was 12+ . I took starter to parts store and it tested OK. Car started after I put the same starter back on last night. I tested voltage across battery with car running and voltage dropped from over 12(off) to 11(running).I suspect alternator because I replaced battery and cables few months back. All connections are clean and tight.
Today:
Car wouldn't start this morning. Turned over at normal speed. I tried using a battery charger, no help. I tested for spark at the plugs and had no spark. I started troubleshooting the Volvo/Chrysler ignition per Bentley Service Manual.
1.Visual inspection- passed
2.Vacuum line to ignition control unit(ICU)- passed (per visual inspection)
3.Power and ground to ICU- passed
4.power to coil- passed
5.coil resistance- slightly high (book calls out 1.1-1.3 ohms found 1.6)
6.ICU switching function- with ignition on, jump terminals C and B on hall sender connector- This did not produce spark at spark plug. I have tested this in the past and was able to produce spark so I don't think I screwed up the test. I am confused about how this works though. I thought the rotor had to be pointing to the correct plug terminal for that plug to fire. This test did not require aligning rotor.
7.Power to Hall sender- passed
At this point the manual says if there are no wiring faults and coil is working the ICU is bad.
Two hours later car starts fine. I drive toward parts store for free diagnostic test and car dies a mile from home. I carry alternator to parts store and it tests OK.
I'm sure the car will start just fine in the morning after I pay to have it towed home. I am not sure what to try next. Replacing the ICU seems fairly drastic at this point, but would be thrilled to pay the $$$ if it is the problem.
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Hi guys, I currently own an 81 264 gle with about 180000 kms on it. Im the second owner of the car and love it to death but recently it just started stalling on me after a number of stop and goes or in warm weather. I have done research on it and I have read alot of suggestions on what might be wrong and this forum has supplied the most details.
The problem is that I am thinking of selling the car but am confused. I read alot of reviews about how bad the b28f and b27f engines are especially in terms of camshafts going bad however my model has a b28e engine and cant find any information relating to this particular type of engine. I live in Australia now and so I bought the car here. Your advice would grately be appreciated and information about this engine as well. I am a student and I seriously dont want to open up the engine and play with the cams. Thanks
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Not sure about your year, but go to www.stepbystepvolvo.com for a no-start diagnosis guide to 740 B230F engines. Might work for your 240.
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I had similair problem, went over lots of stuff. Then gave up and took it to mechanic. He says couldnt find problem but did thoroughly clean all brass ends in the fuse box. Charged me 125$. It solved the problem never died again and always started after that. I could of cleaned the terminals myself. Now I know. 1990 244 sedan
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That's a good call on the rotor alignment omission. For simplicity, you can just attach a plug to the coil output wire. The B-to-C jumper part is wrong too (see below).
I doubt the ICU is bad but you may have a wiring issue between the Hall switch and the ICU.
Below is a "canned" rewrite of Bentley step 6 plus a Hall Switch test...
=============>>>
Three important events are needed for Spark and then Fuel:
A) To get sparks from the coil, the spinning distributor's "Hall Switch/sender" must send weak pulses (1 per cylinder/plug) to the Ignition Control Unit (ICU).
B) The ICU must then respond to each pulse by "triggering" the coil's negative terminal #1 to generate the high voltage in the coil's center wire, to be "distributed" to the proper plug.
C) At the same time, the ICU must also send a timing pulse to the Fuel ECU to keep the Fuel relay energized, control the injectors, etc.
Either test below can be done first, and both assume +12V at Coil terminal #15 with Key On.
Hall Switch Test (tests for A —to initiate B and C above)
1) Pull coil HT wire from distributor cap, attach/adapt to spare (grounded) sparkplug.
2) Remove distributor cap.
3) Rotate engine till an open Vane "window" is centered in front of the Hall Switch.
4) Turn Key ON.
5) Pass a feeler gauge blade (or similar) through the Hall Switch (simulating the moving Vane segment).
•) If the Hall Switch and ICU are OK, you should get a spark at the test plug and fuel pumps should run for a second.
•) Repeat step 5 as needed to verify spark and pumps.
•) If no spark, test ICU operation below (eliminating Hall Switch).
ICU Switching Test (bypasses A and tests only for B and C)
1) Key OFF. (Coil wire and spare plug still set up as in Hall switch test).
2) Remove the 3-wire connector plug from distributor body.
3) Insert a jumper from plug socket B (Yellow wire) to socket C (Black wire). When jumper is REMOVED (step #4) the plug should spark, and the fuel pumps should run briefly.
4) Key ON. Check for spark and pumps as jumper is removed.
•) If Spark & Pumps operate now, suspect Hall Switch or wiring.
•) If no spark, suspect ICU or wiring.
<<<<==================
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
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Lucid,
Thanks for the elaboration on the step 6 test, however I'm not sure what you mean by open vane window. I've got power to the coil and hall sensor but no spark. When I jump the two pins as described in the second test both fuel pumps run and the injectors click, but still no spark. Also, nothing happens when the jumper is removed, only when the jumper is replaced do both pumps and injectors work. I am suspicious of the coil since I got a resistance of 2.5ohms across the primary (about 1 ohm higher than spec). But am not sure if I am doing these hall/control tests properly?
84 240 wagon
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Bruce- thank you for the rewrite of the test procedures. These instructions make sense to me. I have found the Bentley service manual to be well written for the most part, but there are a few multi-step troubleshooting procedures that seem to skip a step. I towed the car home this morning($20 truck rental from home depot, + rope, +good friend) and followed the procedures you provided. ICU Switching Test produced spark. Hall Switch Test did not produce spark at first, then when I lifted the connector off the distributer and jiggled it I got a good spark and heard fuel pump. Looks like loose connections between Hall sender and connector. I'm going to see if I can correct or maybe pick up the parts at junk yard. There is one open till 5:30 on Sun here. I really appreciate all the helpful comments. James
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I wasn't able to find any Volvos with distributer still intact at the junk yard and my attempt to fix wiring in the Hall Switch just made things worse. I bit the bullet and bought a new one. I just put it in and the car started right up. I'm not sure I'm ready for a road trip yet since this just "fixed" an intermittent problem, but I am hopeful. My voltage still drops when I start the car from over twelve with the car off to just under twelve with the car on. I had the alternator tested twice and it passed. I guess I need to start chasing wires.
Thanks again,
James
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"My voltage still drops when I start the car from over twelve with the car off to just under twelve with the car on."
Hi James,
Do you get the panel warning lights when the key is ON, engine off? If not, the alternator probably won't put out, and you'll be running off the (dying) battery. Four of those Warning lights are connected to the alternator D+ terminal via a thinnish red wire, which does two things:
1- Makes a ground path for the Batt light (and the others below*, via diode connections) TO and thru the alternator to ground. [The bulbs have +12V hard-wired to the other side side.]
The bulb current flowing thru the alternator causes it to produce voltage as it spins up. This is sometimes called "exciter" current, or more crudely, alternator foreplay.
2- Once the Alternator is putting out voltage, the wire also carries that voltage back to the bulb circuit to turn the lights OFF, . The D+ terminal (that was at ground level) should rise to Alternator B+ output level. So with voltage now on both sides of those bulbs, no current flows and they go out.
* The other bulbs whose current adds to that of the Batt light are:
• Parking Brake
• Brake Warning
• Bulb Failure
If this doesn't help, I suggest starting a new thread on the subject, or do a Search on it.
Bruce
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
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I do think this problem is unrelated to the one which was hopefully fixed by replacing the Hall switch. I just mentioned it in this thread because it will probably take a few days to fix this before I can take the car out to test the original ignition problem. There is a lot of good info on this site (including your very informative post)that should help me get this charging problem fixed when I have a few hours to get back under the car. It is probably related to the thin red wire off the alternator. I replaced a couple feet of this wire a year ago, but I didn't open up the bundle it hides in because I started to run into good wire. Also, warning lights are out pointing to this ciruit. Thanks for your help.
James
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Have you tried a fuel pump relay? The 85 I had did not have the Chrysler ignition, it was Bosch (redish distributor cap).
The ICU and ECU almost never fail on the 85 but can be found very inexpensively on ebay.
Dan
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for the pickup test, you unplug the coil wire at the distributor. place it somewhere you can see spark jump. so, when you jump b and c, you are mimmicking the pickup as the rotor passes through it. try the test again. if spark is there THEN, then the pickup is bad. still no spark, then the harness or icu is bad. and yes, the ignition harnesses break down, also. especially under the oil pan. sold alot of them when i was in parts in the 80s.
i'm curious-what store were you headed for? i seriously doubt ANY parts store could diagnose that, or any, ignition system. good luck, chuck.
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I was headed to AutoZone for charging system test. When car is running voltage decreases from 12 to 11. I'm not sure if this could be related to my ignition problem. I was hoping it was. I had figured it was the alternator, but turns out alternator tests OK. In retrospect it was kind of boneheaded to leave with the car in the shape its in, but previous days the car drove several miles after starting and never stalled. Thanks for the helpful comments.
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Reliable operations of the electronics does require the alternator and battery to be in good working order. What porkface was saying is that places like autozone won't be able to diagnose ignition problems. Dan
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