• 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!

LH 2.2 RPM signal

G

Greatmoss

New member
Joined
May 1, 2026
Hey everyone I'm new to the volvo community and have some questions about a 1983 volvo 240 DL project have.
I have an LH2.2 fuel system from a 1986 volvo 740 GLE that I'm trying to run on my 240. But in wondering if I can use the ignition coil negative terminal for my RPM signal pin #1 to run the ECU in order to inject fuel. I don't have the funds currently for a distributor with a hall effect sensor. I have everything routed pluss that the intake plumbed and I'm eager to get it started. Has anyone tried this?
 
People have run LH 2.2 with breakerless ignition by using the coil as the rpm. The ECU is not meant to handle this load but people say it works fine. LH2.0 actually uses the coil as the rpm. On an LH2.2 car with either Chrysler or Bosch EZK ignition, the ECU gets the rpm from the ignition controller.
 
Do you think it would be ok as a temporary use on the 544 until I can upgrade to a distributor with a hall affect sensor? And do i need the coolant temp sensor from the 740?
 
Greatmoss said:
Do you think it would be ok as a temporary use on the 544 until I can upgrade to a distributor with a hall affect sensor? And do i need the coolant temp sensor from the 740?
Click to expand...
LH2.2 and LH2.0 temp sensors I think are the same. That's what you're dealing with, right? Look up LH2.0 to LH2.2 conversion. You use a 007 MAF repinned, and you plug in an LH2.2 ECU, the 2.0 harness gives the rpm signal from the coil. Like I said, technically not okay but people do it and I haven't heard of it causing issues.

Is this 2.0 to 2.2 or carb to 2.2 etc?? That's the information we'd need to help you.
 
It's a carburetor to a 2.2 conversion. I have the whole engine plus harness for the b230f out of an 86 740 I had that I would swap but i have to do engine work. I want to get 240 running good so I could register it for the road while I work on the 740 engine since I'm working on a budget rn.
 
You can't use the 740 harness, it's completely different. Unfortunately LH2.2 240 harness are also a crap shoot unless you find an '88.

The easiest way to get a car running well is always by fixing it, not extensively modifying it in hopes that will fix it.
 
I've swapped over the intake manifold, with the fuel rail, injectors, fuel pressure regulator, tps, throttle body, O2 sensor, the MAF and IAC valve from the 740 and routed the 740 harness with the 740 ECU. The original parts on the 240 have been gutted along with the harnes and left with a volvo penta intake manifold with a single barrel. So if I bring it back to stock would it be better to have a 2.2 if say it was originally a 2.0
 
Yes, the ECU grounds the injector wire to energize the injectors. When the ECU isn't grounding it, it will measure 12v since that's what's on the other injector pin.
 
Make sense thank you for you're help. Also would it be better to swap a 530 head from an 86 740 onto my 83 240? I've done a little research and from what im findings the heads of the b23f and b230f are interchangeable.
 
You could but I don't know what the benefit would be. 398 and 530 are functionally the same. 530 will have a different valve cover and the ability to mount a head mounted distributor. Some heads from carb and K-jet engines will not have the ports drilled for the temp sensors or different style of temp sensors. Again, a lot of work just to not run a carb.
 
OVERDRIVE said:
People have run LH 2.2 with breakerless ignition by using the coil as the rpm. The ECU is not meant to handle this load but people say it works fine. LH2.0 actually uses the coil as the rpm. On an LH2.2 car with either Chrysler or Bosch EZK ignition, the ECU gets the rpm from the ignition controller.
Click to expand...
It does work fine but I wouldn't trust it for long.
 
Jack said:
The achilles heel of the Chrysler ignition is the wiring, especially the connector/connection at the box.

Ezk is so much nicer but the Chrysler ignition works too
Click to expand...
I mean triggering the 2.2 ECU off coil negative.

The Chrysler box seems to work well if you don't have a wiring issue.
 
Update on the 2.2 swap, I got it running after messing with the wiring. I only wanted to try thr 530 for the head mounted distributor to get it to run if i couldn't run it with the points ignition I currently have, Im working on the budget to upgrade the distributor and ignition system.
I had everything laying around and figured it would be better to run fuel injection then to run a carburator. I've done some research and talked to the previous owner that swapped it to carb and found out it was originally 2.0.
I wanted to do the swap in hopes of passing emissions due to my strict emissions standards. If I didn't pick this car up it would've probably been scrapped. It didnt have a hood, fender and lights, along with parts being stripped off to fix other 240s basically a parts car for other 240 owners.
 
But now that its running alright the only problem i have is its running rich 10:1 or at least thats what my wide band o2 sensor is reading and it could be wrong or not reading correctly but I doubt it due to the fact you can smell how rich its running.
I had this problem on the 740 I had as well when this 2.2 system was on it, any ideas what it could be or where I should start my diagnosing??
 
A bad coolant temperature sensor, or bad wiring, could cause it to run rich. I'd check the resistance using a multimeter at the ECU connector.
 
Am I checking for a specific resistance between cold temperatures and hot temperatures or just testing for a resistance change with temperature change?
 
You must log in or register to reply here.
Back
Top