Hello all.

Just recently bought this nice 240 from a fellow for $500.And im just getting started with dealing with these old 240's.Whats happening is that the fuel pump just wants to run even with the key set to standby mode.Which i think it should just cycle enough to build pressure then stop.Then it should kick back on during the cranking cycle.I did buy a new relay and the problem is still there.

And i just replaced the intank and under car pump along with the filters to boot.And along with a new FPR which is rated at 2.5BAR.I do not know if this is the right pressure or not.

The things i am thinking it could be are maybe the injectors arent being grounded therefore it will just dump fuel as its getting no input from the ecu.I am pretty confident this is a LH2.2 car but i never seen the ecm placed on the pass side of the engine like this before.

I also checked to see if this car has a cold start injector as that is what causes this problem more often then not.But i wouldnt be so lucky lol.I am thinking tomorrow ill just jump the fuel pump relay and get it to run that way i hope.The other thing that puzzles me is that there is a constant clicking sound coming from both the relays while cranking.

This is the first old 240 i have had to work on in awhile so im a bit rusty.Any input would be helpful.I plan on working on it all day tomorrow till i find the problem.

Thanks
Chris

Thanks for the info.Yeah i was gonna look at the green books but i thought id start with the basics.And so far it looks like this previous owner has done everything that i have known to work.Whats odd now that i jumped the 2 pins that run the pumps is if i revert it to the old configuration the pumps won't come on at all now.Sooo i took the fuel pump relay apart and just move the tab a little and now it runs with the key on accessory mode and starting.So least thats a step in the right direction lol.

I would like to figure out how to test if the ECM and ECU are dead.Now i had the same issue with a 240 i had before that i swapped in a b230FT from a 93 940T and that car had a fire so the computers were toast.So this is starting to lean towards the computers being bad in this car as well.

Now what makes me think this is now its getting to a point where the crank case is pretty much full of gas now and not much oil.So either the injectors are just dumping fuel and getting no signal besides WOT.Which makes sense.I just wish this thing had the handy self diagnostic tools.


The other thing is the wiring harness in this car looks too good to be from 1983.I know the early 80's 2's and 7's had horrible wiring harness's and this would be one of those possibility's that could cause this issue.

Now if i have to ill just get the old carb set up and call it a day.But i really wanna stick with the injection set up as its dead on reliable compared to the later lh2.4 garbage.

If you know of any tests i can run to check out the computers then please let me know.I just wanna be sure they aren't dead.I was thinking i could take the fuel rail and injectors then turn the key and see if they spray or if they don't that would least sorta rule out the fuel computer being bad.

Thanks!
Chris

Volvo's Green Book troubleshooting guide for the LH-2.0 system here:

http://www.scribd.com/doc/47814889/TP30427-1-lh-jet-v2-b23f

But as Art points out, a rotted wiring harness and its amateur workarounds will need to be resolved first. That factory book is primarily aimed at bad or maladjusted components or connections, but it will give you some good info.

And he's right about the Chrysler ignition. They can (like anything) fail, but mine is still functioning just fine 30 years after it left the assembly plant, with the original cap and rotor.
--
Bob: son's XC70, dtr's '94-940, my 81GL, 83-DL, 89-745(V8) and 98-S90. Also 77-MGB and some old motorcycles.

Basics?

Same as carbs. Spark, fuel, compression.

Gassy oil on an LH2.0 could be a faulty fuel computer. It has been known to happen when the old wiring harness shorts out and causes the injector driver transistors to do the same. If I were you, I'd save that guess for last.

More probable, fuel in the oil and cylinder wash down is the result of a timing belt failure or regulator diaphragm. Yes I heard you checked those, but the basics mean you need to pull the plugs. Check spark to all cyls. Use your nose -- if the cylinders are washed down, squirt a bit of oil on the pistons. Check compression -- make sure that t-belt is right.

Fuel means fuel at the right mixture with air, of course. Your engine coolant temperature is measured by a sensor under the 3rd intake runner, best checked with an ohmmeter back at the ECU. If it, or its wiring is open circuit, the ECU will run way too much fuel in for anything south of Pt. Barrow, AK.

Yes, you could pull the rail and watch, but it is much easier to get a $5 'noid light if you're unsure of injectors locked full on. Failing that, you can use your multimeter. Still, I think that's way down the list.

Read the LH2.0 manual. You have to get past the idea the fuel relay is supposed to come on with the key. It isn't.
--
Art Benstein near Baltimore

Much later, when I was discussing cosmological problems
with Einstein, he remarked that the introduction
of the cosmological term was the biggest blunder he ever
made in his life." -George Gamow

Oh the other thing is this car will run perfectly if you run a external tank and do a gravity feed to the fuel rail.Which is very odd.The previous owner did this while we were their as he couldn't get the fuel pumps to come on since they were broken.

Now where do i need to go to check the coolant temp sensor with the ohmmeter so i can see if the coolant temp sensor is working.I have pulled one before out under the intake and that isn't a very fun job.

I also wonder if this car should stop priming the pump when the pressure has built up.Or is it normal for it to just continue running?As of right now none of the pumps will come on unless if i open the relay and stick it on.Least the annoying clicking is gone.And it made the damn pump click on and off too.Which i have never seen anything like that before.


I'll read the green books tonight.Thanks again for the help.Least im heading in the right direction.

"Oh the other thing is this car will run perfectly if you run a external tank and do a gravity feed to the fuel rail.Which is very odd."

Yup. That's kinda odd. Odd anyone would even try it, but I bow to that gumption. The image that arises is, well, how high did he hold the gas can?? And you bought the car.

What it means is hard to say. Obviously, "run perfectly" refers only to idle with no load, so we can't make any assumptions about free-flowing always-open injectors from that. It does mean you have spark and compression, I think.

Pull fuse 12, clean it and its contacts, and re-install. That's the fuse that supplies the system relay with key-switched power, which is probably the one you hear clicking. Just keep in mind I wonder if the circuitry hasn't been tweaked.

"Now where do i need to go to check the coolant temp sensor with the ohmmeter ..."

Let me suggest you register and have a look at the 700/900 FAQ list. This, and a lot of other 7/9 things apply to 240s. The sensor connects to the ECU pin 2, so you measure between the pin on the connector and ground. You'll turn the plug around a few times before you see the tiny pin number embossings on the plastic, so just know that it is a blue wire for pin 2. Green book is great for this, as it includes illustrations and, of course, the temperature/resistance chart. Most will recommend you get a Bentley book, but I might wonder if that costs more than you paid for this gravity-fed potential runner. :)

Welcome to the list!

--
Art Benstein near Baltimore

Married men live longer than single men do, but married men are a lot more willing to die...

Alrighty i have spent my share of time looking at how bad the harness is on this car.Right at the connecting block behind the motor there are a whole mess of wires that have been rigged to hell and back.And after poking around online i think the black wire which is cut out should be for the EFI computer if im correct.I really cannot find a whole lot of info on the wiring block and i have gone through all the green books as well.

I am just really thinking its the wiring harness its been hacked in so many places its amazing anything works lol.Toying with dropping it off at a shop and letting them deal with it.I did also check the resistance at the #2 pin and it seems correct.So thats a plus for now.I also checked and replaced as well as cleaned the connecting points on the fuse terminals for the FI and ignition fuses.And sometimes now the pump will come on just during the cranking cycle.But its very hit or miss still.

I just wonder what all else it could be.The nasty wiring harness is a great issue in its own self.I have never seen so much bare wires coming out of that connecting block as this.

I don't really know what all those wires go to but the black wire showed up on one diagram as the fuel computer.Oh and this car is in fact the bad chrysler style ignition as well.

Later
Chris

The harness is a problem. Chrysler ignition is not.

Best to find an updated harness. Search bartonharness.com and you might get lucky, or you'll be diving into electrical stuff like you haven't done before. A "shop" is not going to have much of an edge over you, unless, perhaps you live in Portland OR or Norcal where these cars are like cockroaches. Most other pro's are going to source a replacement main engine wiring harness or do nothing at all.

If you have the white-cap Chrysler distributor, it can be updated with a Bosch, but that doesn't sound like your trouble. The harness can definitely be the reason your injectors are dumping gas. As you can see here, the rot of the 81-87 harnesses is not limited to what you can see, but lurks inside the vinyl sheathing too.


--
Art Benstein near Baltimore

A boiled egg in the morning is hard to beat.

Hi Chris,

You don't have a book, do you. Go to http://www.k-jet.org/ and read about your car.

A little leg up before you dive into the books.

If the fuel pump runs without the engine turning, it has been modified. Dangerous.

The "ecm" on the washer bottle is the Volvo/Chrysler computerized ignition. The ecm to the right of the passenger's right foot is the fuel computer. Fuel is LH2.0 for 83 and 84 non-turbo, if not messed with. The two silver relays: one gates power to the injectors, idle valve, and amm, while the other serves the fuel pumps -- only when the fuel computer gets pulses from the ignition coil.

The worst problems are sorting out the PO's hacks. Hope you have few.

--
Art Benstein near Baltimore

“The single biggest problem in communication is the illusion that it has taken place.” George Bernard Shaw