Never had a Volvo although many of my friends have owned them. I'm an old 2002, M3 and 328i guy but I admire volvos.

I'm helping out a friend who bought an '82 245 GLT wagon. This car is pretty cool and runs well, but it gets really bad fuel mileage-like 11 or 12 mpg's according to my friend.

I looked at it and changed some simple stuff like the plugs/air filter/fuel filter/rotor/distributor cap. Checked the tire pressures also.

The old plugs looked pretty black i.e. running rich. I just checked what the new plugs looked like after 1000 miles or so and they look fairly black as well. Th front heels seam a little too warm so i check the calipers and the pistons aren't frozen and you can spin the front wheels with the front end jacked up. There is a slight dragging sound from the brakes. When you drive the car it has a rich running smell to it.

What other stuff can i look at? I understand this car has the mechanical fuel injection. I'm thinking of things like the oxygen sensor, fuel pressure regulator, and (hopefully not) the cat. I've also read about vacuum leaks.

 

The culprits is: the control pressure regulator. First check the wiring to it. The harness is notorious for not passing 12v so it can lean out the mixture. Also run several tanks of Techron through the system to free it up. It is varnished over and keeping the plate inside from moving completely into position causing the system to run rich. (The cat would make it feel sluggish at high revs if it was plugged up and vacuum leaks would make it run lean).

 

Howdy. Thanks for your reply. I looked some more at the car today to check out the control pressure regulator. Nice job volvo did of tucking it under the intake manifold to make it nice and easy to mess with! I couldn't pop off the electrical connector to read the voltage.

So, I opened the 8 pin gray connector on the firewall and sure enough the part of the harness that goes to the engine from the 8 pin gray connector is in terrible condition! 6 of the 8 wires have almost no insulation left or it is seriously cracking. Some of these wires must have been touching. No way that control pressure unit could work right with this setup.

So now I'm checking about either repairing this harness by splicing new ends on it or making a new harness. I saw leads going to the cold start valve, a manifold ground, some sensor near the throttle body , probably the control pressure regulator and perhaps the solenoid.

any ideas? thanks!

Oh I forgot to add that a friend has a 78 wagon he is going to junk . According to the Dave's Volvo Engine harness site the pre-1980 cars had good insulation on the harness that didn't rot. Maybe I can get his harness and use it to repair this one.

 

its not a given that a 78 harness would work on a 82 car. there were incremental changes nearly every year. I'd want to compare the 'green book' schematics of the donor and recipient cars before attempting that.

 

OK I was able to loosen the CPR from its mount and take off the electrical connector. I couldn't get off the fuel lines to pull it away and disassemble it like my friend did with his cars. Between the pins on the CPR regulator it read 15 ohms which is to spec I guess.

I had already taped up the bad insulation near the firewall gray 8 pin connector . After this I could read 12 volts at the CPR connector. The meter readout seemed to jump around slightly, not stay steady as when reading the battery.

When cold I read the voltage at the cold start valve and it was zero volts with the key set to "run". I read that this valve only gets voltage when the starter is turning.

I will pull it off the manifold to see if it leaks when the key is set to "run" I guess.

I put everything back together and the car runs, but no idea yet on the gas mileage. I'm helping out a friend who needs the car to go to work and 11mpg is no party with 2011 gas prices!

I have the harness from the older volvo. It has some similar stuff but the 8 pin connector is different and the terminals are too. The terminals on the 82 245GLT are pins and on the other harness they are blades. I'm sure I could swap some of this out w/he 245 harness as the insulation is good on the 78.

I really need to read the fuel pressures. There is a great video on this on youtube. Any ideas on finding a cheap gauge and fittings for this car? I have a few xtra fuel lines for a CPR and could maybe place a gauge between two of these lines (lines run between fuel dist and CPR)

YouTube - ‪k-jetronic adjusting warm-up valve, system & control pressure on golf mk2 gti‬‏

 

somewhere I saw a hack where a guy put a shraeder valve (like a tire air valve) on his fuel line like a "T", and used a 'pencil gauge' 0-100psi tire gauge to measure his fuel pressure. if you ask me, thats suicidal. (high probability of fuel spraying everywhere. difficulty in ensuring rubber seat on shraeader valve pin is gasohol safe. etc etc. at a bare minimum I'd want a METAL dust cap on this with a good gasohol proof o-ring inside to ensure the gas stays where it belongs).

a proper fuel pressure gauge with the volvo specific thread attachments is a fairly expensive bit of kit. :-/

 

You can splice directly into the cold start injector wires from the top connector. All it needs is 12volts w/ignition on. That's what makes it work along with a ground. Get that right and your gas mileage will improve. Secondly, make sure the O2 sensor is working and adjusted. There is a connection point right under the ignition control unit which is right in front of the coil. The wire is read and the only one there. Connect a dwell meter to it and you can adjust the fuel/air mixture through the little hole on top of the fuel distribution unit. These two things have to be right.

Next are the fuel injector seals. Pour water on them with the engine running. If the engine stumbles, replace them with 17mm ID - 21mm OD O-rings from the hardware store. They will make gas mileage poor as well.

The fuel pressure is governed by the control pressure regulator. You really don't need a fuel pressure gauge. You can wire the other bits directly to the connector as well. The harness to the engine is what fails. The wiring to the connector is fine. It is only there to make taking the engine out easier. There are: The wire from the alternator, the air valve (Idle control motor), the control pressure regulator, the balast resistor back to the coil, the cold start injector and the oil pressure sender. They can (and ultimately do) share a common ground.

Once you get the control pressure regulator connected, run techron through the tank several times. It needs a good cleaning if it has been stuck closed.

 

Alright I poured some Techron into the tank. I could read 12 v at the CPR connector although it seemed to waiver a bit.

My next question is the frequency valve. The functioning of this valve changes the fuel pressure. I'm going to check it for voltage. You can hear or feel it buzzing when the car is off or running? If this wasn't working the valve would be stuck open which would increase the fuel pressure and the car would run more rich.

I've read that the connections to the computer (pin 15?) can be corroded or that they can suffer the same fate as the other wires in the harness with bad insulation. One could always just run a jumper wire to the computer to bypass the harness. Also, I've read that the DC resistance of the frequency valve should be 2-3 ohms.

I might even open up the CPR to see how corroded it is and hook it up to voltage to see if the bimetal strip moves.

Oh, I did verify the operation of the CSV. I pulled it off of the manifold and cranked the engine while it was in a no start condition. The CSV made a nice mist cloud of fuel for a few seconds and didn't drip fuel with the key left to "run" position. So this seems to mean that at least part of the engine wiring harness is working.

 

OK I just messed around with this car again. I looked to see if the frequency valve was working.

I can confirm that it indeed makes a buzzing sound and that the car won't start with the connector removed from the frequency valve.

With the key set to "run" and the engine not running there was no voltage across the leads.

 

There won't be voltage unless it is running. It responds to the changes in the O2 sensor and part of the lamda system. Do you have a dwell meter? Sounds like you have voltage to the CPR, FV, CSI. You should also have voltage to the air valve (idle control motor). Those are the main support bits for the engine. Check those O-rings on the injectors for air leaks. That will make you use more gas as well.

 

I didn't check that idle air valve yet for voltage. I sprayed some throttle body cleaner around various spots while the engine was running to see if i could get a rise out of it, so to speak! The only spot that will do that is near the throttle body/CSV. The revs will go up maybe 50-100 for 1/2 of a second.

I sprayed that stuff near the injectors and the revs didn't go up.

Someone showed me a dwell meter today. I never really used one. I know that they were used to do something with the old school points but you can use them for k jet frequency valve? How would you hook this up?

You know, there was this bare lead with a crimp connector on the firewall. I fished around and found the lead to the 02 sensor hanging near the block. I reconnected it, but I have no idea if it is good. I bought another Bosch one but I didn't install it yet.

The frequency valve read 3 ohms with the connector off which is to spec.

All there is to do really is either read the control pressure or take apart the CPR and clean it out.

BTW, the fuel pump is noisy on this car. Another friend has two wagons I might be able to get parts off of for free so maybe I'll get one of his pumps.

 

the idle regulator shouldn't affect mileage in any material fashion, its just an air bypass on the throttle, and would at worst mean crappy idling.

 

I'm gonna work on this a little later today. We had 2 CPRs apart yesterday. The one from this car has a heater element that gets hot and deflects the bimetal strip .035 inches. We took the valve apart an it looked clean.

I have the second CPR apart from another car and I'm gonna plug it into the harness to verify that the heater gets hot in it when you have the key to run. I'll have the correct CPR installed so gas doesn't go flying.

There is a test port connector mounted on top on the valve cover with two leads that I'm sure has something to do with the 02 sensor.

i may try adjusting the dwell and then go for a fuel mileage run.,

 

Well things are looking up. After reassembling the CPR and trying the car out I was initially disheartened. The car wouldn't run right-really choppy. I swapped out the body with that from another CPR and the car would run.

So the diaphragm in the first one was not so hot and we made it worse by taking it apart. I made one CPR from the parts I had using the second diaphragm and the car ran with this. I could verify that the bimetal strip was getting hot with the car running(tricky thing to do!) so the wiring is ok.

I did a fuel mileage run (40 miles on the highway) and when I topped the tank up the car has used 2 gallons so that's 20 mpg.

I still need to swap out the o2 sensor, set the dwell and fix the overdrive. Thanks for all of you info and ideas!

 

For fun I did some searches to check the availability of the warm up valves. I found them listed on Amazons site for pretty good prices. The one for this turbo car is listed for $118. Its a rebuilt unit by a company in California called Python Injection. Pretty good deal since the ones listed on ebay are $950.

I don't know how this works but there is a 1-2 month delivery time listed. They have other regulators listed as in stock for as little as $50.

 

That's an air leak around the gasket. That should be replaced or cleaned and reseated.

There is a read wire down by the Ignition Control Unit in front of the coil. Hook the red wire from the dwell meter to it and the other to the battery neg. This will show you the dwell of the lamda system. If the O2 sensor is working, the dwell should oscillate about 5 degrees. Set it in the middle at 40. (you may have to double the 8 cylinder readings).

One last thing to consider: check every last one of your connections under the hood. All should be clean and tight especially the grounds. Undo them and clean them. You'll notice a big difference in fine-tuning the thing.

Hope that helps.