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Old 02-01-2019, 10:17 AM   #51
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Is there something you missed because the car was a diesel? And must be wired different that's a 2.2 car?
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Old 02-01-2019, 11:29 AM   #52
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Quote:
Originally Posted by bobxyz View Post
Disconnect the distributor and the powerstage. With key on, measure and write down these voltages:
1) battery + post to - post
2) distributor harness connector + to - pin (the outer 2, the middle pin is the signal)
3) powerstage harness connector pin 2 to 4 (if you look at the powerstage itself, with the connector facing you, pin 1 is on the right, pin 7 on left)
4) coil #15 pin to battery - post
5) manifold ground bolts to battery + post
Report back with the measurements when done.

Edit: I just looked at the LH2.2 conversion harness doc and there's one more thing to check.
[step 3 of doc] The harness includes a 4-pin cabin connector. The red/white wire in this connector comes from pin#1 of the coil, to your tach.

Check that the existing 4-pin connector in your dash has the red/white wire and that it goes to the tach. If your connector has a different wire, or it's not plugged into the tach (clock pins are a common mistake), then pin#1 on the coil is shorted to something in the cabin. This could cause the coil to not fire.
1. 11.85v (ignition on)
2. 10.67v 4.87v
3. 11.84v
4. 11.83v
5. 11.85v

Tacho is not connected. Car doesn't have that 4 pin connector, I wired the switched power and left the other 3 alone for now.

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Originally Posted by ZVOLV View Post
^^^He knows what he is talking about. Listen and follow.

Pin 2 of the powerstage is ground to the intake manifold. BROWN wire. Pin 4 of the powerstage is BLUE wire and it also powers the EZK. If there is no 12v between pin 2 and pin 4 of the powerstage your EZK, and also your powestage, are not juiced up.

If there is no power to the MAF yellow/blue wire, your LH box is not powered up.
MAF power wire- 10.80v
Powerstage 2 to 4- 11.84v
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Old 02-01-2019, 11:58 AM   #53
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Why do you have two readings for measurement number 2? He asked you to measure only between pins 1 and 3 of the dist plug, key on. 5v?!

Do you have power to the injector positive wire???!
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Old 02-01-2019, 12:00 PM   #54
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Thanks for the measurements. They look surprisingly close to each other for being scattered about the engine compartment.

I expected the #2 (disti) measurement to be ~0.6v lower than the others (due to a diode drop in the EZK +12v power to disti), but yours is a little lower still. Can you measure
1) - battery post to - pin on disti connector (should be ~0.0 volts)
2) + battery post to + pin on disti connector (I'd expect ~0.6v)

For the 4-pin connector are you saying that you did not need to wire up the fat red/yel wire to your fuel pumps? And just needed to wire the red/blk ignition switch #15 wire?

Can you post a link to a greenbook for your car? I don't think I have one.

[edit: BTW, you can't use an ohm meter with the power on. The meter applies its own voltage to make the measurement and, if the circuit you're probing is powered up, it confuses the meter.]
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Old 02-01-2019, 12:13 PM   #55
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Confirmed computers still get power under cranking. The 5v reading is between pins 1/3 of the dist connector, which is what it should be.

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Originally Posted by bobxyz View Post
Thanks for the measurements. They look surprisingly close to each other for being scattered about the engine compartment.

I expected the #2 (disti) measurement to be ~0.6v lower than the others (due to a diode drop in the EZK +12v power to disti), but yours is a little lower still. Can you measure
1) - battery post to - pin on disti connector (should be ~0.0 volts)
2) + battery post to + pin on disti connector (I'd expect ~0.6v)

For the 4-pin connector are you saying that you did not need to wire up the fat red/yel wire to your fuel pumps? And just needed to wire the red/blk ignition switch #15 wire?

Can you post a link to a greenbook for your car? I don't think I have one.

[edit: BTW, you can't use an ohm meter with the power on. The meter applies its own voltage to make the measurement and, if the circuit you're probing is powered up, it confuses the meter.]
1. 0.014v
2. 1.228v

I just connected to the pump to ignition power for testing purposes, it's disconnected at the moment.

I dunno how useful these could be, but this is what I've found.

1988 diagram http://brickspeed.net/VolvoDocs/240-..._240__1988.pdf
1981 diagram http://www.240.se/litteratur/tp30316.pdf
87 740 Haynes diagram http://brickspeed.net/VolvoDocs/740-...60_od_1987.pdf
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Old 02-01-2019, 01:47 PM   #56
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So turns out some idiot (me) put pins 2/3 back into the dizzy connector backwards after they came out. Swapped em round and nothing changed, did I fry the hall sensor?
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Old 02-01-2019, 02:08 PM   #57
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Does the hall sensor get 12v or 5v power from EZK? I don't know.

I would use a scope to look at the square wave output signal of the hall sensor.
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Old 02-01-2019, 02:16 PM   #58
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With the meter there's just no connection between any of the 3 pins on either distributor. Again, dunno if this is right.

EDIT: Pins 2/3 were swapped, so 12v was going to where 5v should be going, and 5v to where 12v should be.
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Old 02-01-2019, 02:16 PM   #59
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Your 2nd pair of voltage measurements seem OK (probably 2x 0.6v diode drops on power filtering). With this, you have good voltage levels at the connectors (but this doesn't always mean the voltages are good when connected up and running).

I don't know if connecting a hall sensor incorrectly would damage it. On the disti side, are the pins are labelled - O +? If so, which ones were swapped and what are the voltages for - to + and for - to O? I'd also inspect the connectors carefully to make sure the pins will make good contact when assembled (no spread contact fingers, and won't push out).

Can you get to the backside of the connector pins when everything is plugged in? If so, check the - to + voltage again, then measure the - to O voltage while cranking (or when spinning the disti by hand). It should move between 0 and (I'm guessing a bit here) 5volts as the vanes go through the hall sensor gap. If so, your hall sensor is working.

For fueling, the main fuel pump relay on the K-Jet cars use a red/white wire from the coil to turn on the fuel pumps when running. I don't know what the diesels do. Do you have more than 1 red/white wire on pin 1 of your coil? And what is powering the fuel pumps if you haven't connected the big yel/red wire from the harness?
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Old 02-01-2019, 02:53 PM   #60
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Okay, making progress. Distributor is working, switching between 5 and 0v as I rotate it. Injectors are firing every time the hall sensor triggers, so that's working now. Still no spark though.

For testing I just connected the fuel pump to an ignition switched fuse. I'll do it properly sometime. Diesel doesn't have an electric fuel pump. The wiring was there, just not connected to anything.
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Old 02-01-2019, 03:25 PM   #61
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Quote:
Originally Posted by Cwazywazy View Post
Okay, making progress.
Great!

I'd unplug the injectors, to keep from filling up the cyls, and keep spinning it by hand until you have working spark.

First off, unplug the center lead from the disti and fix it next to a shock tower bolt, or something easy to see, then spin by hand. Cleanflametrap has a nice picture showing a magnet and one of the single-wire valve cover plug wire holders setup for spark testing.

If you have spark, then the problem is between the end of the coil wire and the plugs. If not, you could try measuring the voltage between pin #1 of the coil and Battery + post while spinning by hand. This will be +0volts most of the time, but should briefly blip up when the coil is charging during the dwell time. Dwell time is roughly 0.01 seconds, so it's hard to see the blip with a meter.

If you don't see the meter twitch, you can try the same thing with the EZK to powerstage signal if you can probe it when connected. You want to probe powerstage pin #5. The EZK to powerstage wire, for a '87 740, is green (sorry, I misread GR as OR initially) but I don't know what it is in your harness. [Edit: probe this one to the battery - post, the EZK signal is 0v and pulses to +5v during coil charging.]

For the fuel pumps, they draw a pretty high current so you want them powered through a relay, instead of drawing all the power through the ignition switch. The harness that you have includes the relay, you just need to run the fat yel/red wire to fuel pump fuse(s), assuming that they're present and wired to the pumps.

Last edited by bobxyz; 02-01-2019 at 03:43 PM..
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Old 02-01-2019, 03:35 PM   #62
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Good work! If the hall sensor is triggering and the signal for that is sent to the fuel computer you get the pulsing on your injectors. Now if you still don't have spark. You have to test the signal from the power stage to the coil. Is there anyting else connected to the red white wire on the coil? Besides the coil and the powerstage?

If there is switching then the secondary part of the system from the coil to the coil wire, dist cap, rotor are next along the path.
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Old 02-01-2019, 03:36 PM   #63
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Originally Posted by bobxyz View Post
Great!

I'd unplug the injectors, to keep from filling up the cyls, and keep spinning it by hand until you have working spark.

First off, unplug the center lead from the disti and fix it next to a shock tower bolt, or something easy to see, then spin by hand. Cleanflametrap has a nice picture showing a magnet and one of the single-wire valve cover plug wire holders setup for spark testing.

If you have spark, then the problem is between the end of the coil wire and the plugs. If not, you could try measuring the voltage between pin #1 of the coil and Battery + post while spinning by hand. This will be +0volts most of the time, but should briefly blip up when the coil is charging during the dwell time. Dwell time is roughly 0.01 seconds, so it's hard to see the blip with a meter.

If you don't see the meter twitch, you can try the same thing with the EZK to powerstage signal if you can probe it when connected. You want to probe powerstage pin #5. The EZK to powerstage wire, for a '87 740, is green (sorry, I misread GR as OR initially) but I don't know what it is in your harness.

For the fuel pumps, they draw a pretty high current so you want them powered through a relay, instead of drawing all the power through the ignition switch. The harness that you have includes the relay, you just need to run the fat yel/red wire to fuel pump fuse(s), assuming that they're present and wired to the pumps.
That is how I'm checking spark.

Between coil pin 1 (red/white) with it unplugged and battery + the meter sits at battery voltage with no blip. Between powerstage pin 5 (probed through the back with it connected) and battery + it blips from 60mv to 75mv when I turn the dizzy.

Nothing else connected the coil. I have two cheapie powerstages in addition to the old Bosch one. Only difference I can find is that while the bosch has about 10kohms between coil pin 1 and ground the cheapies have an open circuit. Neither of these match what mrak said.

Quote:
Originally Posted by mrak View Post
For the record, I checked resistance between negative and ground like you asked. With the ignition off it was 18 - so basically nothing, and with the ignition on it was very high.

Last edited by Cwazywazy; 02-01-2019 at 03:42 PM..
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Old 02-01-2019, 03:37 PM   #64
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Great troubleshooting writeup Bob!
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Old 02-01-2019, 03:49 PM   #65
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Oop, I probed powerstage pin 4 not 5. Pin 5 sits at battery voltage, same as the coil wire. Popped the old EZK back in and no change.
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Old 02-01-2019, 03:51 PM   #66
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Originally Posted by dl242gt View Post
Great troubleshooting writeup Bob!
Yup, I really appreciate all the help.
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Old 02-01-2019, 04:14 PM   #67
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For checking the coil pin 1, leave it plugged in.

Sorry, for the powerstage, I snuck in an edit on you:
[Edit: probe this one to the battery - post, the EZK signal is 0v and pulses to +5v during coil charging.]

If you measured +12v between pin 5 and battery + post, then this is equivalent to measuring 0v between pin 5 and battery - post. If you re-measure with battery - post, it may be a little more sensitive and show the blips.
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Old 02-01-2019, 04:28 PM   #68
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Since you can get to the back side of the powerstage pins, here's a few more voltages to check. With everything connected (injectors can be unconnected) and key on, measure between powerstage pins and battery - post:
pin 1 - red/white wire to coil, 12volts and, depending on meter, may blip when turning disti.
pin 2 - black ground, 0volts
pin 3 - shield, probably 0volts
pin 4 - red, +12v power
pin 5 - green, spark signal from EZK, 0volts and may blip when turning disti.

One other thought, check the top of the coil and find the embossed pin numbers in the plastic. Pin 1 = red/white wire, pin 15 = blue (?) power wire, yes?
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Old 02-01-2019, 05:01 PM   #69
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Quote:
Originally Posted by bobxyz View Post
Since you can get to the back side of the powerstage pins, here's a few more voltages to check. With everything connected (injectors can be unconnected) and key on, measure between powerstage pins and battery - post:
pin 1 - red/white wire to coil, 12volts and, depending on meter, may blip when turning disti.
pin 2 - black ground, 0volts
pin 3 - shield, probably 0volts
pin 4 - red, +12v power
pin 5 - green, spark signal from EZK, 0volts and may blip when turning disti.

One other thought, check the top of the coil and find the embossed pin numbers in the plastic. Pin 1 = red/white wire, pin 15 = blue (?) power wire, yes?
Measured all 5 from the back of the powerstage connector to battery -, ignition on, and I got what you wrote (12v on 1/4, 0v on 2/3/5) but no blipping when turning dizzy. Coil is connected correctly.
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Old 02-01-2019, 05:18 PM   #70
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OK, seems to be no spark signal from EZK to powerstage, or the blip is too small to catch on your meter. I think you can check for a blip from EZK with the powerstage unplugged. You'd measure voltage across harness connector pin 5 to battery - post, while spinning disti (key on). Anything? [If it were me or ZVOLV, this would be a great time to put an oscilloscope on that pin.]

Next, turn if off, unplug the EZK and measure resistance between powerstage connector pin 5 and battery - post. Since EZK is unplugged, this should be an open circuit. If the wire is shorted somewhere, it will usually show some resistance to ground.
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Old 02-01-2019, 05:22 PM   #71
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I can usually see the trigger signal as a varying voltage on a digital meter if the metter is fast enough. Usually looks like it varies from 0~3v. A scope would be nice though.
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Old 02-01-2019, 05:44 PM   #72
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OK, seems to be no spark signal from EZK to powerstage, or the blip is too small to catch on your meter. I think you can check for a blip from EZK with the powerstage unplugged. You'd measure voltage across harness connector pin 5 to battery - post, while spinning disti (key on). Anything? [If it were me or ZVOLV, this would be a great time to put an oscilloscope on that pin.]

Next, turn if off, unplug the EZK and measure resistance between powerstage connector pin 5 and battery - post. Since EZK is unplugged, this should be an open circuit. If the wire is shorted somewhere, it will usually show some resistance to ground.
Okay, so it is blipping up to about 3v at pin 5 with the powerstage unplugged but with any powerstage plugged in it sits at 0v. Open circuit to ground with ezk unplugged.
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Old 02-01-2019, 06:02 PM   #73
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Hmmm..... Seems like you're good to the powerstage, but then goes bad. I'm trying to think of something that fits your symptoms and part swaps, but don't have anything likely.

A bad powerstage shouldn't drag down the input signal. It would more normally fail with either the output shorted to ground, or no output at all, but the input signal would be fine.

If you disconnect the coil from the powerstage (disconnect and tape both pin 1 and 15 on the coil), with power stage plugged in, does it blip on powerstage input or still nada?

Edit: I'm still suspicious that plugging in the powerstage causes problems. This is a longshot: With key off, ezk unplugged, and powerstage unplugged, measure the resistance between pin 5 and the other pins in the powerstage connector. It should be open circuit for all.

Unless someone else has a suggestion, it sure seems like it's time to try yet another powerstage if the above tests don't find anything. The powerstage is basically a beefy power transistor on a heatsink, so most any brand, or junkyard used, should be OK.

Last edited by bobxyz; 02-01-2019 at 08:24 PM.. Reason: one more test...
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Old 02-01-2019, 11:16 PM   #74
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Hmmm..... Seems like you're good to the powerstage, but then goes bad. I'm trying to think of something that fits your symptoms and part swaps, but don't have anything likely.

A bad powerstage shouldn't drag down the input signal. It would more normally fail with either the output shorted to ground, or no output at all, but the input signal would be fine.

If you disconnect the coil from the powerstage (disconnect and tape both pin 1 and 15 on the coil), with power stage plugged in, does it blip on powerstage input or still nada?

Edit: I'm still suspicious that plugging in the powerstage causes problems. This is a longshot: With key off, ezk unplugged, and powerstage unplugged, measure the resistance between pin 5 and the other pins in the powerstage connector. It should be open circuit for all.

Unless someone else has a suggestion, it sure seems like it's time to try yet another powerstage if the above tests don't find anything. The powerstage is basically a beefy power transistor on a heatsink, so most any brand, or junkyard used, should be OK.
Coil unplugged makes no difference. With EZK and powerstage unplugged pin 5 shorts to pin 3, open circuit for the rest. In the dbarton harness guide it says pin 3 is a shield for pin 5.

I tested the rest of the pins though and found that pin 2 and 4 are shorted. Pin 2 is connected to the manifold ground. Pin 4 is ignition coil positive. But when I plug in the EZK and turn ignition on I get 12v at pin 4 and pin 2 is grounded.
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Old 02-02-2019, 12:43 AM   #75
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I tested the rest of the pins though and found that pin 2 and 4 are shorted. Pin 2 is connected to the manifold ground. Pin 4 is ignition coil positive. But when I plug in the EZK and turn ignition on I get 12v at pin 4 and pin 2 is grounded.
Without looking at a wiring diagram, and without seeing how your harness is built, this is probably OK. Pin 2 and 4 are main ground and main +12v. I'd guess that even with EZK unplugged, that there are other components still wired up. If you want to check, on the lowest resistance setting, hold the probe tips together and write down the value. Should be close to 0.0 ohms. Now, re-measure 2 to 4 (ground to +12v). I'd expect it to be 10ish ohms, but that's just a wild guess.

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With EZK and powerstage unplugged pin 5 shorts to pin 3, open circuit for the rest. In the dbarton harness guide it says pin 3 is a shield for pin 5.
I think you've found it!!!

3 shorted to 5 is very bad, the shield should connect to ground and nothing else. If it's shorted to pin 5, it grounds the spark signal from EZK to powerstage, and you'll get no spark. I'd guess that the accident damaged the cable and either the accident, or the repair, caused the short. I'll find a picture of shielded cable tomorrow -- it has an insulated center wire surrounded by a metal woven shielding sleeve. They should not contact.

Can you peel back the plastic harness sleeving a couple inches? If so, the quick&dirty test would be to cut the pin 3 shield wire a couple inches from the connector (do it so you can reconnect it later if needed). The shield connection isn't necessary for startup, but might be needed to prevent occasional misfire.
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