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I've been watching the recent "HELP! My car won't start" thread, with the hope I'd figure out my problem. I didn't. I've posted this on two other Volvo forums and got 1 reply to check something, which wasn't the problem. If you can solve this one, you'll forever be a genius in my book.
I have an '89 760 with 235k. About 3 weeks ago I pressure washed the engine to try and find an oil leak. Afterwards, the car started and ran fine for a couple hours. I got home, shut it off, and went to move it 10 minutes later and it wouldn't start. I've found there to be no spark, and I have determined this using my timing light.
I have a friend with an identical car, and we started swapping parts. I swapped the ignition module, the distributor, the coil, and the radio suppression relay, one at a time until eventually all of those parts from my car were on his car, and his parts on mine. In each case his car still ran, and mine wouldn't.
I can hear the fuel pump working when I crank the car, and when I pulled the plugs they were fuel soaked. Aside from that, they had no indication of anything but normal combustion. I also checked the injector connections with a noid light and they're all getting a signal. With the key in the "ON" position I have 12v at the coil, and I've checked every fuse. They were all good.
All I can think of now is a crank sensor, but for the life of me I can't find it. Autozone has a listing for one, as do several online suppliers I use, but I've looked all over the bellhousing and the crank pulley in front and can't find a sensor. Is this one of those odd years where they hid it somewhere?
Any suggestions?
Thanks
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An update, just in case anybody had a brilliant idea but couldn't find the original thread. I got my fingers crossed.
I had to go out of town for work, and before I left I dropped the car off with a local electrical specialist. I've used the guy before, and he's always been really good.
I got home, went to see him, and he says he checked everything he could find (which is all the stuff I had already swapped with my friends car), and everything is good. He suggested that the only other thing would be the ECU. I pulled mine out, swapped it into my friends car, and his car still ran. I put his ECU in my car, and mine still won't start.
So now I've stumped the electrical specialist.
Thre is only one other think that's a little odd, and seriously, I'm grasping for any answer with this one. When I crank my car, there is a strange knocking sound. It's coming from the starter, and when I grab the starter while it's being cranked I can feel something inside hitting the housing.
So...is there some ignition signal that somehow gets sent through the starter when it's cranking, that maybe isn't going through because something inside is broken? Electrical is not my thing, and like I said, I'm grasping at any possible answer now, regardless of how strange.
As always, all thoughts appreciated.
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I went to the good Volvo diagrams at this Russian Site (scroll down for your FI and Ignition). They show that you should see +12V as soon as the Key is ON at coil 15 BLue wire). I think you should also see it (thru the coil primary) at coil 1 (R-W wire), but am not sure. If you do, it should also blink as you crank. That would verify that the power stage was working, meaning the coil secondary should be producing high voltage.
The confusion on the Mitchell diagram becomes clear, with the Volvo diagram. The Key-On 12V goes from the Ign Sw via BL-R wire to the back of fuse 12, then to the back of fuse 13, where it leaves on two BL wires:
One BL wire passes thru two connectors on its way to Coil 15
The other splits at a connector to become two BL wires:
> One to EZK CU 6
> The other to Power Stage 4
Hope this helps. I strongly suggest an incandescent (not LED) Test light to quickly verify good voltage or not. I know from your earlier post that you saw 12V at the coil. But if that was on a digital meter, I'm not convinced.
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
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I've seen older cars, without computers and such, that would crank and crank and not start. Then, just when you let off the key, they would start under momentum, or at least fire a couple times. I always took that to mean that the starter was pulling so much power that there wasn't enough left over for the ignition system to work. So, it may be possible, and maybe even more likely on a computer car that requires specific voltage. To check it, maybe you can feed either the starter or the rest of the system with a separate battery and see what happens.
Have you checked to be sure that the timing belt didn't slip?
Charley
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...especially if you've already had it to an electrician.
But has anyone checked for a good +12V at the coil (blue wire) while cranking?
Since the FI is working, it must be getting timing pulses from the EZK. Based on those pulses, the EZK Power Stage should also be triggering the coil. Was PStage terminal 5 checked while cranking?
(I think maybe using an AC setting on the DVM?)
Here's the long shot. The later turbos get the coil +12V from the RSRelay (which gets picked by the Fuel relay). But the only diagram I found so far (a Mitchell online) shows that the '89 turbo coil is powered from Fuse 13?!?.
A fused coil? That's new to me.
Put a 12V test light (not a DVM) on that blue wire coil terminal. If there's no light while cranking, there will be no spark. Meaning fuse 13 is on the suspect list.
If there is a good light, it should blink or go dim when cranking. A steady light would suggest the coil isn't being tickled buy the Power Stage.
EDIT: The online Mitchell shows fuse 13 just being used as a common terminal having:
A blue wire to coil
A blue wire to power stage
AND a blue wire to (from?) the FI ECU terminal 18???
But the Mitchell Turbo ECU diagram shows a blue wire from 18 to the coil???
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.
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While I have never had the opportunity to try this method of checking the hall sensor it appears to be quite easy to perform.
To test the hall sensor:
(1) Pull off one spark plug wire and attach directly to coil with spark plug in the end, connect the plug base to a ground.
(2) Disconnect the harness plug from the distributor
(3) Switch ignition "ON"
There are three contacts in the connector. They are arranged in a straight line. With the ignition "ON" one of the connectors (on one end of the row or the other) will show 12v to ground. If you can not get 12v from any of the pins when the ignition is switched "ON" and you do not suspect the wiring at fault between the plug and the ICU then suspect the ICU being the fault.
(4) If you find 12v at one of the pins carefully use a jumper to briefly connect the remaining two pins. Each time you jumper those two pins the plug should spark.
In this test the jumper is replacing the effect of the hall sensor. If you get a strong spark with this test and you were getting no spark out of the coil when cranking the engine the hall sensor is faulty.
Randy
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I tested the hall sensor as suggested. I get no spark, but each time I hit the contact with the jumper I can hear the fuel system pressurizing. I tested the coil again, just to make sure, and it tests good.
Still scratching my head.....
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As I mentioned I have never used the method to test a sensor before and I do not have any cars here with a sensor to test. My son's 88 744t does not reside here.
You are sure you had the plug grounded? I wish I could be of more help.
Randy
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Interesting test. I'll try it, but I did swap the entire distributor into a running car, and it still ran with my distributor in it.
I've got 12v at the plug from one of the wires, about 6v from the center wire, and 0v from the third wire. I'll try this test and see what happens.
Thanks for the suggestion.
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Have you cleaned all your ground contacts in the engine compartment? Two on fuel rail, one set behind battery, one on pass frame rail from battery and the one below the power steering pump.
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'89 turbos have lh2.2/ez-117K; no crank sensor.
Check the connector on the bottom of the distributor.
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The plastic connector on the distributor is new. When I pulled the distributor for testing, I saw it was broken and replaced it. As such, I'm assuming the connection is good.
I'll check grounds, as another suggested, but I'm not hopeful. Given the way it died, suddenly and instantly, my guess is that it wouldn't be a ground connection. I would think that would present itself as an intermittent problem before it died completely.
At least now I don't feel like an idiot for not being able to find the crank sensor.
I appreciate the suggestions so far.
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If you look down at the top of the bell housing from the RH (exhaust) side of the engine bay, you should see the sensor on top of the bell housing. It's just barely to the RH side of dead center.
You do have the B230 turbo and not the PRV V6, correct?
If you find no crank sensor in the bell housing, you may have a hall sensor in the distributor, but 1989 should have it in the bell housing - at least the 740's do.
Have you read out the fault codes in the OBD?
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