Thanks to all who reply in advance. This is my first post and I will try to be clear. This is a friend of mine's car. It is an 87' 240 Wagon. However, the engine is a b23f, I believe out of an 83' But all of the ignition and fuel injection is from the 87'. The vehicle ran great until one day my friend said he had hit a huge pothole and the car started to run very poorly. Smoking and barely running. He was able to get it a few blocks home where he shut it off and it wouldn't start after that.
This is where I come in. I am a mechanic. I have owned and worked on a number of volvo's over the years. I first checked spark and fuel both good. Great Spark. Then checked Cam and ignition timing both good. Vehicle will not start. Checked injector pulse and duration both good. I have performed the control unit input tests which all passed. I have also swapped out both the Ecu and Ignition Control Modules Both from a fresh wreck at the junkyard. Every once in a while it will magically start and run for a while. Still very poorly however. Then it will stop running and have the same symptoms again. Sometimes it will only fire on one cylinder even though all spark is good and injectors fire simultaneously. I know that the wiring on these vehicle's can be an issue and I have not gotten into the harness yet. Since all of the important things for combustion are present.
I stumbled accross a post by jd620 regarding very similar symptoms but I did not see if the problem was resolved. Any input is greatly appreciated. Thanks

One more common problem area is the 25 amp ignition fuse and holder near the battery. The connections to the fuse and at the battery get corrosion on them causing no start problems. Dan

Hi GP-
I ran into a real similar problem in an 88 245, same kind of scenario. Turned out the small wire had broken at the alternator, and I think was grounding out. The guy's alternator had previously fallen off due to a loose bolt, and had been put back on but the harness here was not fixed.

The wires go through a tight spot between the alt bottom bracket and the block. Look for damage here, along the wiring harness in the two clamps under the crank pulley, and right on the back of the alternator. Make sure alt ground wire (blue wire usually has a red Volvo part ID tag on it) is in good shape while in there. The space is a bit tight, up against the oil filter and right motor mount, I know.

Look at the 8 pin grey connector on the firewall. The red wire here is that same small red wire on the regulator connection on the alternator. Is it bare or crumbly? The harnesses usually show problems here. If that's the case, try to disturb it as little as possible. On most of these cars that I've owned, I've re-routed the red wire and the oil pressure switch wire around the right side of the engine compartment, along the firewall and through the strut tower and down to the alternator. This works well and Volvo should have done it like this- would have saved thousands of tows and repairs for owners over the years. Requires one splice up at the grey connector for each wire rerouted.

I know you said you checked timing, but make sure also that the dist rotor is pointing to the tick mark when it's at TDC. You're clear on the location of all the timing marks I assume so I won't explain how to read those.

Another good test, and the most common problem with these cars most likely, is a failure of the fuel pump relay. I know you said it's getting fuel, but just make sure by trying another relay. Location is under dash, right side, firewall in front of glovebox. Relay PN 3523608.

And try to check out the cat and exhaust for damage. If it took a really hard shot, it's possible the exhaust is crushed somewhere allowing no flow out, and that would possibly prevent starting.

Good luck with it!


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::: Rob Bareiss, New London CT ::: 92 244 ::: 90 745GL ::: 90 745T ::: 84 242DL ::: 90 745T Parts ::: Used to have : 86 244DL, 87 244DL, 91 244, 88 244GL, 88 744GLE, 82 245T, 86 244DL, 87 244DL, 88 245DL, 89 244DL!

a big vacuum leak?

I've read something about a slipping harmonic balancer (crankshaft pulley) throwing timing off.
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1980 245 Canadian B21A with SU carb and M46 trans in Brampton, Ont.

I am with another poster...

Disconnect the Air mass sensor. If the car starts and runs then, you will have to replace it. (Disconnecting it puts computer into "limp home" mode.)

You don't want to run it that way for long, though. (Unless you want to also replace the cat converter.)

If that's what it is, note that the air mass sensor is very expensive. See if you can pick up a rebuild.

The 87's are the vintage of the biodegradable wiring harness. Chances are some insulation is frayed and either lines are parted or are grounding out somewhere. Start at the gray connector on the firewall, and trace the harness forward toward all engine-end terminations.
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Thank goodness we don't get all the government we pay for. -- Wiley Post

Off the cuff, assuming an 87 has one, crank position sensor is toast. Its located just behind the head at the top of the bell housing, if the harness is frayed... you just found the problem.

jorrell

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92 245 245K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently in pieces

1989 was the first year for the crankshaft sensor with the intro of LH 2.4... so there won't be one on this '83/'87 hybrid car. :-) It will have a hall sensor in the dizzy... basically the same thing. Though in theory, if you have good, reliable spark, that should be good.

If we've got solid spark and fuel, we just need to have air and fuel in the right mixture. Have you tried pulling the connector to the AMM to see if the car'll run? I guess a sudden jolt could mess that up. Other than that, I guess I'd check the wiring to the sensors and the sensors themselves.

-Ryan
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Athens, Ohio
1990 245 DL 130k M47, E-codes
1991 745 GL 290k (Girlfriend-mobile)
Buckeye Volvo Club