• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Saving a 1992 LH 3.1 M47 245 a few questions

ZVOLV said:
To be honest, I can't tell what is currently the issue with your car. I can't recall it all, or haven't read and reread your posts, but you, I, and CFT have some rapport so I will do my best on my time off to help.


I haven't honestly ever heard of a RWD brick running ok and then when hot it takes a dump. Actually, lying, I have, it was the ignition module overheating. I had it happen on a 740 once. It would run fine cold, but then die hot.

If I were you, honestly, I would fire a crank sensor and powerstage/ignition module at it and hope for the best. If your time is worth more than the parts, go for it!

There are basic voltage test you can do to test powerstage, but I am not gonna take the time to research it/explain it right now to be honest. Again, that being said, powerstage causes a DEAD car. NOT misfires. I could be wrong. But I would supsect those two things based on experience and information provided, well at least the information I have processed and somewhat remembered. Car in hand is always best.
Click to expand...


I appreciate both of you taking the time to help. At this point I want to understand why the car is having these problems. It is something that will always bother me if I don't figure it out or someone else figures it out and I have zero experience with LH 2.4 or 3.1 so you guys have a big advantage on me there. The good thing is I have managed to keep a lot of Volvos running without any diagnostics as well and based purely off experience and information from a lot of other wise Volvo owners. Hopefully this gets sorted and we can all add it to a known problem to help the next guy around.

I guess there is a reason that the PO and the PO before him didn't get the car running . Amongst the parts my friend brought me there is a good powerstage and crank sensor. I will throw those at it just to see. I need to pick up a new DP gasket as well so I can put the 02 back in the downpipe when I swap it to a earlier DP .
 
O2 won't ever cause a no start. It is ignored at startup.

Computer goes by coolant temp, MAF, and maps to get the bitch fired up. Hot stalls and hot startup issues suggest to me that something electronic is taking a hot dump.

I suggest you do your research, in the name of science, to learn how to diagnose the powerstage and crank sensor. power stage basically converts 5 volt computer speak to 12v coil speak. The rest is up to you.
 
Ok I think I am on the right track here . After setting the enrichment screw back a little bit on the diesel 244 to try and eliminate black smoke and getting the idle reset and fooling with its power steering I decided to do a little work on the black wagon which I call "Darkness" btw .

Anyways I tested one of the RPM sensors (crank sensor) that I had and was reading 18 ohms and then I pulled the one in the car and tested it and it read 18 ohms. now I read the link you sent me ZVOLV but I was only getting one reading on two of the pins . Also when I pulled the sensor from the car it was coated in oil so it looks like a have a rear main leak to deal with... yay . I sure need to invest in a lift . and I am serious about that .

I decided to put the other one I had in . And let me just say that is one heck of an annoying part to take out and put in . My arm and hand did not like those positions :ninja:

So with not much hope in the swap I went to start the car.. no luck.... OH WAIT ... I forgot to hook up the sensor to the plug .

after a few cranks the car fired up . I let it run for a good 10 minutes and then I gave it some gas and it sputtered a bit and died. By this time is was warm and the 02 is working because I went to check it and it seems that the heated wire actually gets the sensor to temp rather quick . I shut the car off and restarted it . it cut off a few times here and there but always started back up so now I am at a point where I need to get the 02 sensor back in the exhaust.

I am not sure why this sensor worked and maybe the other wasn't but I wonder if oil had something to do with it . you wouldn't think it would but I was reading and the air gap in some of these sensors can effect readings . My brain is pretty fried from today so I can't properly explain what I want to say but some how this works . I am going to try to get the exhaust back together this weekend .

I just don't quite understand really . The car ran so the sensor should have been good and testing it through the ecu tested to be good. So why when I changed the sensor am I able to start and stop the car again like I had done when I first got it running? This is still all confusing and some how I don't think this is the whole picture . Also the ECU relayed no codes while the 30 minutes I ran it off and on.
 
Last edited:
Alright! Turned the key and got it running again today. it doesn't run well after it gets warmed up but thats the 02 out of the exhaust and maybe something else but at least I can start it and move it now .
 
ZVOLV said:
Wait, so you don't have an O2 sensor at all!? You need to install that!
Click to expand...

Don't you remember the post where I pulled the cat back off the car to confirm the cat was good or bad? The 02 went into the cat which I am not a fan of so I am swaping to a DP with a bung in it for the 02 . ATM the 02 is hooked up and the heated wire is working but it is reading way to much 02 in around it for obvious reasons So I know that to proceed properly from here I need to re-install that 02 into the exhaust . But the 02 should have never caused a starting issue which I confirmed it didn't . So my theory works. The car runs ok until it is work and then it starts dying once everything is warmed up meaning the 02 is reading some wack info !

In the end this thread will pose to be a wonderful Journal entry for myself to read. Thats the only reason I keep posting on it every day. and Maybe, Just maybe another LH3.1 person can get something useful out of it. I don't really post on TB much for obvious reasons. I think most folks want a giant turbo on their car regardless if it runs or not so usually that will be the hottest topic of the daily discussions . Do I get a turbo the size of my head or keep my car running... meh who needs a car running anyways . TURBO HEAD IT IS ! haha . And if anyone didn't get a good chuckle out that then OH WELL , I did because Laughter is good for the soul .
 
Last edited:
240 JAH said:
Don't you remember the post where I pulled the cat back off the car to confirm the cat was good or bad?
Click to expand...


Nope. I get confused in all this text sometimes.


Thread needs more pics!


So wait, do you have an O2 sensor mounted in the exhaust stream or not?
 
Last edited:
ZVOLV said:
Nope. I get confused in all this text sometimes.


Thread needs more pics!
Click to expand...

lol like a picture book with step by step of what I did. I could see it happening but I don't have much time to snap up the photos while messing around with this car but in the mean time here is a cool photo of my 1970 164 and a little video of the b30 ... Now I can tune some dual SU HIF6 Carbs without the help of 5000 sensors and it runs and starts every time even in zero degree weather .

D668B820-C04C-422E-845E-8F1DB801D005.jpg


Cold start on a cold day
<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http://vid1199.photobucket.com/albums/aa471/SuperJA5000/volvos/IMG_5965.mp4&title=">

and don't forget the 1984 244 Diesel that also does not use a ECM/ECU .

06BA53C4-4A88-463E-A315-74469AB73E1B.jpg


<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http://vid1199.photobucket.com/albums/aa471/SuperJA5000/volvos/IMG_5697.mp4&title=Diesel%20244">
 
Ok guys. I have a wild idea here. I really think the rpm signal sensor (crank sensor) was a bad idea to use on these 240's . what was wrong with pulling the signal off the dizzy like LH 2.2 uses. Do you think I could make the system work off a 2.2 dizzy and wiring it in to send the rpm signal off that? It just makes a lot more sense to me. I think that I may get into some experimentation with this black car in the long run.
 
Higher definition signal=more precisely calculated fuel injection events is my conjecture.


Hall effect=square wave signal over just a small rotating distributor. RPM sensor is a large flywheel and different signal.


My question to you before I go any further is, how does modern EFI determine there is a misfire? What sensor could possibly determine this and how the heck does it know which cylinder?
 
ZVOLV said:
Higher definition signal=more precisely calculated fuel injection events is my conjecture.


Hall effect=square wave signal over just a small rotating distributor. RPM sensor is a large flywheel and different signal.


My question to you before I go any further is, how does modern EFI determine there is a misfire? What sensor could possibly determine this and how the heck does it know which cylinder?
Click to expand...

Well if we are speaking of OBDII (Modern EFI) Then they use the speed of the crankshaft between cylinder firings to determine any misfires . and they are using a crankshaft position sensor to detect the revolutions of the crankshaft any any alteration to that will cause the ECU or PCM to log a misfire. Any misfires are recorded every 200 revolutions , which is pretty fast counting in all reality . The computer can determine which cylinder misfired off basic math. when the crankshaft missed a beat !

Now the real question is .... could a redblock run on OBDII haha ;)
 
Awesome reply. Ok, so...why are you asking about running a hall effect 2.2 sensor on a 2.4 car? Confused.

Is your 02 mounted in the exhaust stream, or no? If no, I imply that is your hot running issue. That is VERY tbricker to run without an 02 sensor and expect the engine to run properly in closed loop. How the heck is it supposed to know what is going on?
 
ZVOLV said:
Awesome reply. Ok, so...why are you asking about running a hall effect 2.2 sensor on a 2.4 car? Confused.

Is your 02 mounted in the exhaust stream, or no? If no, I imply that is your hot running issue. That is VERY tbricker to run without an 02 sensor and expect the engine to run properly in closed loop. How the heck is it supposed to know what is going on?
Click to expand...

hah I totally mentioned that I agree that the 02 being out of the exhaust is part of my issue now when the car warms up . Prior to getting it back to running status I did not see the 02 causing a no start issue . It still has hard starting btw but hopefully I will get that ironed out. I am not driving the car mind you and I have 8 other volvos to deal with so I have no put the exhaust back together yet hintz why the 02 in not in the exhaust , however it is hooked up.

Well maybe I was misunderstanding . I consider MODERN EFI systems to be OBDII but it seems that the LH3.1 and 2.4 have a bit of this going on as they are learning computers so once you got me to explain that back to myself and I thought a little more about 2.4 and 3.1 I see the issue . I still feel like there could have been a better location and way to do this though. at this time I do not have the better way but let me research it some more and I might find one or I might not but its good to learn.
 
Either way, your car needs an O2 sensor to run in closed loop. Yeah it will start cold and run in open loop until certain parameters are met and then it goes into closed loop and starts to listen to the O2 sensor. If you o2 is just danglin in the breeze, that aint gonna cut it! LH will go WTFwherestheo2sensorbalaaslfhjadsfja;sdl
 
ZVOLV said:
Either way, your car needs an O2 sensor to run in closed loop. Yeah it will start cold and run in open loop until certain parameters are met and then it goes into closed loop and starts to listen to the O2 sensor. If you o2 is just danglin in the breeze, that aint gonna cut it! LH will go WTFwherestheo2sensorbalaaslfhjadsfja;sdl
Click to expand...

Yes . I understand this. This is why I said I haven't got around to it. until then I am not messing with the car other than to start it every day . The 02 is functioning and the heated wire is working so once it gets to temp the 02 is sending a signal back to the ECU telling the car that something is seriously wrong. However it is not sending any codes because the 02 is working and is plugged up .

I am not saying the car should run without a 02 or will I drive it that way. you are preaching to the choir .

I will post up when I get the exhaust back on and sorted out. It will be sorted out soon .
 
I bought this car from josh a week ago. As of right now it runs but has a massive misfire in cyl. #3 and wants to die. Also the o2 sensor is still out of the exhaust.
 
Yes I sold "darkness" to Todd here this past weekend. I had gotten the car running from a no run status after it had sat for years. It was last on my list of things to do so Todd will continue on where I left off. Below I have quoted some information previously tested in this thread. so If anyone would like to help Todd out here, please read what has already been done to the car to get it to run status. From what he has told me he has already swapped the stock injectors to clean green tops that he had laying around. I am not sure if this will effect anything before the ECU has time to learn but figured I would throw that out there. Spark plugs are new and gapped properly, rotor and cap are new and so are wires. Coil is tested good. Known working white label ecu was added a long with a known AMM A known working crank angle sensor was also put in. All diagnostics checked out at the test box and below you will see everything from the ecu checked out . even the ones that say not good as "art" has mentioned there was a typo in the book.

fuel pressure checked out good and compression checked out good as well.


240 JAH said:
Ok here goes :

ECU - Test ( These test are conducted mainly at the ECU harness plug but a few are else where in conjunction with the ECU plug)

T35 +G - ECU power Supply from ignition switch - Ignition On = 12V GOOD

T9 +G - ECU Power supply from main relay - Ignition OFF, Terminal 21 Grounded = 12V GOOD

T4 +G - ECU Power Supply from battery - Ignition OFF = 12V GOOD
T5b +G - ECU Ground connections = Continuity ALL GOOD
T17 +G ^
T19 +G ^
T29 +G ^
T5 and T19 ^
T5 and T29 ^

T20 and 21 Grounded - Fuel pump power supply from main relay - Ignition ON = Fuel pumps operate GOOD

T9 and 18 - Fuel Injectors - Ignition OFF = 4.0 ohms Variance of +.6 ohms (actual reading 4.6 ohms) Good?

T9 and 32 - Cold Start Injector = DOES NOT APPLY (SKIP)

T13 +G - Coolant Temperature sensor - Ignition OFF - Resistance according to current temp = I got a reading of approx 1500 ohms after briefly running the engine which roughly works out to 85ish degrees so the sensor is GOOD.

T2 and 10- Throttle Sensor LH3.1 - Ignition OFF - throttle closed = approx. 2800 ohms (actual reading of 2860) GOOD

T2 +G - Throttle Sensor LH3.1 - Ignition off - Throttle open = Approx. 1200 ohms and resistance should increase as throttle is open ( Actual reading started at 1033 ohms and went to 2600 at WOT) GOOD?

#3 Terminal on AMM plug +G - Air Mass Meter power supply - Ignition ON and ECU Terminal 21 Grounded = 12v GOOD

#2 Terminal on AMM Plug +G - Air Mass Meter Ground - Ignition OFF = Continuity GOOD

T6 and 7 - Air Mass Meter Film - Ignition OFF = 108 ohms (Actual reading 113ohms) GOOD

T30 +G - Engine cranking signal - operate stater = 8V Minimum ( Actual reading 11.5v) GOOD

T1 +G - Engine RPM signal - Engine cranking = 8V minimum (actual reading 6v) NOT GOOD
Would this bad signal have something to do with the Crank sensor on the bell housing ?

Vehicle speed sensor - SKIPPED

T26 +G - Upshift light (manual trans) - Ignition off = Continuity = NO CONTINUITY NOT GOOD

T28 +G - Anti Knock Sensor - Ignition OFF = Approx. 0.7V (Actual 0.7v) GOOD

T24 +G - O2 Wiring Harness - O2 Connected = Continuity = NO CONTINUITY NOT GOOD
T24 +G - O2 Wiring harness - Separate connector and wire Green wire to Ground = No Continuity = CONTINUITY NOT GOOD
I am not sure why the readings are backwards??? ANY THOUGHTS??

Check Engine Light Signal - SKIPPED

T9 and 33 - Air control valve - Ignition OFF = Approx. 8 ohms (actual 8ohms ) GOOD

AC Microswitch - SKIPPED

AC compressor Signal - SKIPPED

So if anyone has some opinions on these finding please post them . I am rather tired tonight so I cannot research any more tonight . I see that I have a RPM signal problem and a 02 wiring harness problem ... Not sure what the deal is . I tried out two different O2 sensors on that test as well.
Click to expand...

cleanflametrap said:
http://forums.turbobricks.com/showthread.php?t=224897 I know I added the error on the oxygen sensor wiring harness to the latest Bentley Errata list, but I don't see it in this link, and doesn't look like it made it to the "10th printing." Anyway, your readings are correct. The book is wrong.

Also, that pin 1 reading is a switched output from the EZK, a long way from the crank sensor which someone's meter might have averaged to 8V. Below, the upper trace is what that pin looks like normally.

Digital meter DC readings on switching circuits are not really very useful, but the authors of the greenbooks (from where Bentley was derived) really did not have much experience with these cars before they even hit the market,, and may not have been writing to dealer service departments with digital multimeters back then.

ezk9043.jpg
Click to expand...
 
240 JAH said:
...stock injectors to clean green tops...
Click to expand...

Like are those for Turbo engines? If so, remove...

Acquire a good timing light...mark crank's TDC mark with white chalk... wait for the sun to go down....examine light pulse in darkness while engine is cranked...or running, if the case. If it does not start, pull plugs, and smell them.

Do you have access to a scope?
 
You must log in or register to reply here.
Back
Top