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Any LH2.4 conversion experts in Dallas want $?

Yep, that's the harness I got. It did seem like the wire going to pin 18 was grounded even with the ignition off. But since it has basically the same symptoms it did with the last harness, I guess both harnesses would have to be shorted similarly. I'm pretty sure (?) I tested everything the way you suggested...

I don't like to say this out loud but I am using one of those $4 Harbor Freight multimeters. I know everyone will say they won't do the job but I think for very basic stuff they do. It's a glorified test light.

Thanks for the links!

Well I gotta say if pin 18 is grounded even with the ignition off then that does not sound good for your ECU!

I'd think the Harbor Freight multi would be good enough!
 
I'm going to go get the spare ECU this evening. I just pulled the plugs to un-hydrolock it. I turned it over for a while with the plugs out and the injectors unplugged, then I decided to see if I had leaky injectors which I've already checked a few times. I pulled the rail and re-grounded the injectors, plugged them in, turned on the ignition and pressure-washed the car next to it with gasoline. Injectors 1,3, and 4 spray gas so hard once the key is turned on it's unbelievable. Injector 2 does nothing for some reason. All 4 injectors have 12v with ignition on. I haven't tried swapping the number 2 injector for another one to see if it's a clogged injector, but I really doubt it. I think it has to be the ECU at this point. Famous last words...again.
 
So I put the other ECU in and... it runs smooth! No smoke either. It did stall after a couple minutes but I'll figure that out later. Probably just out of gas from dumping it all into the crankcase and out the exhaust. I'd mess with it more tonight but it's a little late and right now the car just has a downpipe. It does at least look like the ECU was definitely the problem like you guys kept telling me. It took almost two hours to get from N. Dallas to S. Dallas, and I thought I was leaving towards the end of rush hour. And that's why I procrastinated about going and getting this stupid ECU.

So first I plugged the injectors in and grounded them with the rail removed like before, and tried turning the ignition on with the new ECU. Before, 3 injectors were spraying fuel like crazy. Now, no injectors were spraying but the pumps were still running continuously. I tried bumping the starter a little to see if the injectors sprayed at all much less in a controlled manner, and they did in fact appear to work correctly. So I put the rail back in and started it up. Idle was a bit low but smooth. Sounded really good. Tomorrow I'll change the oil again and then poke around some more, see if I can get it up to temperature.

I'm pretty happy! Thanks everyone for the help! And of course, it's always possible that the new ECU will fry itself tomorrow.

By the way, old ECU from 93 945T donor was a 937 model, new one from 94 945T is a 967. What's the difference?
 
Well as long as you don't run without the resistor pack / ballast resistors I think you won't have any problems.

Let me quote you and also bobxyz:

I've also tried different injectors - right now it's running the correct injectors and resistor pack that came with this 93 B230FT, but I've tried N/A injectors with no resistors just to see if it would idle at all. No luck though, same symptoms.

How good was your original resistor pack wiring - are you sure that nothing was mis-wired or shorted out before you tried starting it for the first time? If you tried to start it and the ECU side of the injectors was shorted to +12, or the resistor pack wasn't correct, you may have damaged the ECU. I'm not sure how quickly the damage occurs -- I don't know if it would have started and fried in minutes or only a few seconds.

For repair instructions, see:
http://ipdown.net/jetronic.info/tiki-index.php?page=HOWTO%3A+LH2.4+Injector+Driver+Replacement

You'll need a TIP122 ($0.55) [the original is an ON823, or similar darlington transistor, and the TIP122 is generic substitute]:
https://www.jameco.com/z/TIP122--Major-Brands-Transistor-Darlington-NPN-100-Volt-5-Amp-3-Pin3-Tab-TO-220-Bulk_120416.html

So if you go to that HOWTO http://ipdown.net/jetronic.info/tiki-index.php?page=HOWTO:+LH2.4+Injector+Driver+Replacement at the very top it says

If you accidentally use low-Z (low impedance) injectors without a resistor pack, the injector driver will supply too much current and subsequently cook itself. Symptoms of this are a car that won't run (or only runs briefly with the injectors disconnected) and a crankcase full of gasoline.

These Volvo injectors are certainly Low-Z since they all come with a resistor pack, this means the resistance is in the pack and not in the injector. If you run them without the resistor then the circuit will be effectively UNLIMITED so will fry the drivers supplying the power. High-Z injectors have higher resistance internally so do not need the resistor pack. (http://fuelinjectorclinic.com/faqs/)

Anyways, awesome that you figured it out! And replace that stuck injector!
 
Back when I tried the injectors without the resistor pack, I was using injectors from a non-turbo, yellowtops. I thought they would be High-Z? Anyway, I obviously fried this ECU somehow no matter what because it worked fine in the donor car.

From what I could tell, all 4 injectors looked to be spraying nicely with this new ECU. I let them spray into a plastic container a little so I could watch. It's a mystery to me why only one was not firing before when they're wired to all fire together, but now all 4 appear to work. Maybe handling the injector connectors on this lovely harness was making an intermittent connection at that #2 injector. But yeah regardless I'll be triple checking everything like this and making sure it's all working right.

Since it basically works now I'm very apprehensive of switching back to the last harness, but I still think I'd trust it more than this DB one for futureproofness. I talked to him about it and I know it's not his fault, it's the people who put it together in the Netherlands. I was just annoyed before...the harness problem didn't help with my stress level on this project. But of course he wouldn't have the reputation he has if he had problems like this often.
 
Back when I tried the injectors without the resistor pack, I was using injectors from a non-turbo, yellowtops. I thought they would be High-Z? Anyway, I obviously fried this ECU somehow no matter what because it worked fine in the donor car.

From what I could tell, all 4 injectors looked to be spraying nicely with this new ECU. I let them spray into a plastic container a little so I could watch. It's a mystery to me why only one was not firing before when they're wired to all fire together, but now all 4 appear to work. Maybe handling the injector connectors on this lovely harness was making an intermittent connection at that #2 injector. But yeah regardless I'll be triple checking everything like this and making sure it's all working right.

Since it basically works now I'm very apprehensive of switching back to the last harness, but I still think I'd trust it more than this DB one for futureproofness. I talked to him about it and I know it's not his fault, it's the people who put it together in the Netherlands. I was just annoyed before...the harness problem didn't help with my stress level on this project. But of course he wouldn't have the reputation he has if he had problems like this often.

Oh, well good point. I didn't know that since I haven't had a non turbo since like high school! Looking at some schematics you are right about the ballast. Only thing I can think of is maybe measure those yellow tops. The faq says:
If the resistance is between 8 and 16 Ohm you have high impedance injectors.
You're probably right though so I don't really know what caused the inj drivers to blow up then 8(
 
I'm sure I swapped various injector related wires around in some desperately idiotic way. I don't really remember now, there has been a lot of beer since then. On the bright side I think this whole experience has made my slightly less dumb. I have another B230FT awaiting my other 85, and that one's an M47 244 so it should be pretty fun too. My hope is that I've learned enough now to do that one without getting stuck.
 
Great news! Just need to find the emoji for the Happy Volvo Dance. :)

Since it sounds like you have the tool to de-pin the connectors easily, I'd certainly de-pin and inspect the crimps on the injector that wasn't firing.

I'm also guessing that the brief period where it ran with the new harness and old ECU was due to the poor crimp on the injector driver pin -- poor crimp causing extra voltage loss, resulting in not fully open injectors, which cut down the flow enough to not flood it immediately.

937 vs 967 looks like the 967 is just a slightly newer B230FT turbo ECU - see: https://www.volvoclub.org.uk/faq/EngineFIComputer.html#ECUAMMReferenceChart

The turbo greentops are low-z, the N/A orangetops are high-z (no r-pack needed)
 
I applaud your drive to upgrade these 240s 8)

Thanks!

So here's today's mystery. It starts and idles 'pretty' smooth but not perfectly smooth. The problem is still with the number 2 injector. With the old ECU, injectors 1,3, and 4 were all pressurewashers and 2 did nothing. Now with the new ECU, Injectors 1,3, and 4 pulse perfectly but 2 is a pressurewasher. I tried switching injectors 1 and 2 and the problem stays with the #2 spot on the rail. Any ideas?

Here's a video:
https://youtu.be/-1piDEDGCko
 
#2 mis-wired in harness???

With engine off, unplug all 4 injectors. The ECU side of each injector connector should be wired together; the other side goes to individual resistors in the R-pack. Measure pin1 to pin1 to pin1 to pin 1, then do the same for pin 2s. One set of measurements should all be ~0 ohms, and the other set should all be ~18 ohms (I'm guessing a bit on this value, but it would be twice the resistance of a single resistor out of the pack).

Edit: if the pins going to the r-pack don't all match each other, unplug your rpack and measure each of the 4 resistor pins to the common center pin on the R-pack itself. All 4 should match (guess of 9 ohms each). Also measure each pin to the metal cage - all should be open (no connection)

Edit#2: skip the above, just remove your resistor pack and inspect it carefully. I'm pretty sure you'll find that the injector side of the resistor for injector#2 is shorted to the metal cage.
 
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#2 mis-wired in harness???

With engine off, unplug all 4 injectors. The ECU side of each injector connector should be wired together; the other side goes to individual resistors in the R-pack. Measure pin1 to pin1 to pin1 to pin 1, then do the same for pin 2s. One set of measurements should all be ~0 ohms, and the other set should all be ~18 ohms (I'm guessing a bit on this value, but it would be twice the resistance of a single resistor out of the pack).

Edit: if the pins going to the r-pack don't all match each other, unplug your rpack and measure each of the 4 resistor pins to the common center pin on the R-pack itself. All 4 should match (guess of 9 ohms each). Also measure each pin to the metal cage - all should be open (no connection)

Edit#2: skip the above, just remove your resistor pack and inspect it carefully. I'm pretty sure you'll find that the injector side of the resistor for injector#2 is shorted to the metal cage.


Ok, bear with me on electrical terminology and basic skill. So for the record my cute little Harbor Freight meter, when set to ohms, reads "1" when nothing is being tested. I started with the first test that you suggested.

Injector 1 pin 1 to injector 2 pin 1 = 7 ohms (slowly dropping)
Injector 2 pin 1 to injector 3 pin 1 = 7 ohms
Injector 3 pin 1 to injector 4 pin 1 = 13 ohms (what?)

Injector 1 pin 2 to injector 2 pin 2 = "1" (nothing?)
Injector 2 pin 2 to injector 3 pin 2 = "1"
Injector 3 pin 2 to injector 4 pin 2 = 8 ohms

I removed the resistor pack and it looks like crap in general, to me everything looks rusted and shorted to everything. I have not yet taken a closer look at the specific resistor for injector 2. About to go look at that. Using the multimeter is something that won't get the cops called on me for doing on my driveway at night.
 
I didn't finish the testing tonight afterall. Will do in the morning. But it sounds to me like you're saying the resistor pack is suspect, so maybe I'll just swap it for another one to be completely sure. I will be where my 94 945t is tomorrow, working on a family member's 940 which I'm responsible for putting them in and therefore feel responsible for maintaining, but anyway I'll be able to get that resistor pack while I'm there.
 
Well, I'm confused by your measurements. They're not what I expected. Out of the bunch, the only one that seems good, as in the circuit is good, is the 13ohms.

The pin 1 measurements that include injector 2 are 7ohms and would make sense if the injector 2 rpack resistor was shorted to ground. The pin2 measurements don't make sense.

If the r-pack is still unplugged, can you measure each injector pin to ground? All should be open circuit. You could also try visually tracing the pin 2 wires (if you can bunch up, or roll over, the protective sleeving to expose enough of the harness). The pin 2 wires should all be crimped together to what was originally a white/green wire to the ECU.
 
Both with the R-pack unplugged and plugged in, ohming pins of and 1 of all 4 injectors to ground, my meter just reads "1". I guess this means they're an open circuit? Not sure. I'll try to look beneath the sleeving to make sure all the pin 2 wires are crimped together, while trying not to make this new harness look like a complete hackjob.
 
Ok, it was just another really dumb thing on my part. I had the IAC wires and the injector 2 wires switched. I don't know how it was able to look so natural that way, or how it ran as well as it did. With that little problem solved, it started and idled perfectly. I turned it off after about 5 minutes just because I can't currently monitor temperature. Got to put this car back together now that it's starting to cooperate.
 
It's doing pretty well! I immediately put it to work. The only thing is the transmission tailshaft bushing completely died so I'm waiting on a new one to come in. But this thing is ...fast. It's already smoked a Mustang GT. I'm not into street racing but I just found that particular situation amusing.

 
It's doing pretty well! I immediately put it to work. The only thing is the transmission tailshaft bushing completely died so I'm waiting on a new one to come in. But this thing is ...fast. It's already smoked a Mustang GT. I'm not into street racing but I just found that particular situation amusing.


Great! Aww, what are you doing to that poor 744? I always considered white 744s to be pretty rare.
 
Why is it poor? I rescued it! It's been my daily driver for the last few days while I wait on the tailshaft bushing to come in for the wagon. I'm keeping this 744. I M47 swapped it and did IPD springs a couple years ago for my friend. Now he decided he didn't have time for it anymore (it just got done sitting for 2 years) so it's mine now ;-)
 
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