This is my first post and and my first volvo experience. I need some guidance. I had a 78 244DL given to me with only 45'000 miles on it because the previous owner could not get it going and left it in his barn for years.It is in great shape for liveing in Northern New England. Over the last month I have gotten pretty far but have one nagging problem. The car will start and run great for about 1 to 1.5 miles then it picks up a miss that gets progressivly worse within 30 seconds to a min. until the engine stalls. After setting for 30 seconds the car will start right up and run great through the same sequence. I am suspecting that the trouble is with the CPR but I believe that has to do with a cold engine and mine runs great when it first starts hot or cold. I have a spare parts car so I have swapped some parts to no avail and am looking for some help. This is what I have done so far. IT is the 1978 year B21F motor with the K-Jetronics mechanical fuel injection.
1)Flushed tank, New internal and external pumps. The car holds holds 70-73lbs even when the motor is sputtering and dies, the accumulator holds between 20 and 30 lbs line pressure overnight. The injectors are spraying a good pattern. Return line is clear
2)Cleaned the sensor plate and the whole intake area. Checked 1,2,3... times for vacuume leaks for leaks around boot.
3) changed coil and coil wire
4) Good exhaust flow through catalytic converter
5) Tried running with no gas cap to prevent gas tank pressurization( Is it normal to hear escaping pressure when removing gas cap?)
I will take any suggestions at this point. It is too nice of a car to ship it to the junkyard just yet but not so nice I want to put a lot of money into it by haveing a dealer work through this. Thanks in advance Steve

Just checking but have you replaced the fuel filter? A clogged fuel filter would give you the cut out in the flow to the injectors when you move the Air Flow Sensor Plate. Also keep in mind that if you have the LAMBDA SOND (O2) Sensor System you need to make sure that all of the systems grounds are clean and making good contact with the intake manifold. If you have the 02 Sensor System then you also have Frequency Valve which adjusts the fuel pressure in the fuel distributor. If the system is not working correctly then the frequency valve will be causing the fuel pressure to back up making it difficult for the injectors to spray the right amount of fuel into the engine. You can check to see if the frequency valve is working by checking the duty cycle from the test point found by the battery and the headlight relay on the drivers-side fender. Good Luck and keep us posted!

Sincerely,
--
Julio Meza

1979 264GL B27F 125K --> BW55->M46, CLS, IPD Sway, 81+ Dash, Gauges, Flat Hood & E-Codes

1979 262C B27F 160K --> Restore Project w/Possible B280F

1984 245DL 214K -->Wifemobile

I never thought of hot wireing the cold start.I might try that after I get the controller back in. My first thoughts after verifying I wasnt losing intermediate fuel line pressure was that the return fuel line was clogged/plugged causing an buildup of pressure at the fuel distributor that was creating some sort of problem. I tend to think this would create a rich problem though. or that the catalytic converter was plugged/clogged creating a buildup of exhaust backpressure thus interrupting air flow through the intake. My check for this was to hold my hand over the exhaust (with welding glove) and there seemed to be plenty of flow/pressure. This problem is very baffeling. If I lift the air flow plate with the fuel pump jumpered I get a continuous "variable" (depending on the position of the plate)flow of fuel from the injectors and no significant drop in fuel pressure. butwhen running and the symptoms develop, any application of throttle and the engine bogs (not a hint of black smoke) but will come back to a strong idle until symtoms get progressivly worse to a stall. I am still thinking that the problem might be in the exhaust because the car starts right back up and any exhaust backpressure would bleed off quickly upon shutdown. Keep the thoughts comeing. I appreciate the input. I am actually kinda likeing the challenge with the car and gaining some knowledge also. Fortunatly its not the main sorce of transportation. Steve

hi there can you pull the 02 sensor to relieve pressure or is it downstream of the cat? i have less experience than you i just want to follow this thread as i have a k-jet system in my new old turbo. i took voltage readings from the 02 sensor to check for rich/lean condition, and had to reset the fuel dist. i read in the bentleys manual the gas cap should be on for the system to work properly. is the lambda relay buzzing your frequency valve? i will be purchasing the bosch fuel injection manual very soon i was told it is a very informative. the bentleys i have describes how to measure fuel flow in graduated beakers and also at the return line, seems to be important. i hope you can solve this situation.

So the sequence is the same weather the engine is hot or cold? Doesn't sound like it could be any of the temperature controlled systems. I assume giving it more throttle doesn't prevent the stalling and that the miss continues. You might want to devise a temporary way to give it more gas just to determine if leaning is the problem. Perhaps and wire and switch to the cold start valve. I've also heard it is possible for a catalyst to become clogged.

thanks for the thoughts guys. I have changed the fuel filter and have been running my pressure gauge after the filter in the system also this model has no O2 sensor on the manifold. The car does the same thing if I just start it and let it Idle but it takes it about 15 min before it stalls this way.I dont suspect the fuel relay because My pressure remains a constant. I removed the cpr today,disassembled, cleaned and will reinstall tomorrow. I found no real problem here like plugged ports or obvious problems. I have 12V coming to it and show resistance through the circuit. I think I need a better book my CLymers just doesnt go to the depth I need. any suggestions or web sites I might research?

I have an '81 which I bought in '85 with 90kmiles. It's close to 300k now. It does sound like a fuel leaning problem. If you just start and let it idle does the same thing happen? Does this year have the exhaust sensor and frequency valve aka Lambda system? If so try unplugging the exhaust sensor. This will put the system into a fixed default mode and prevent any changes. You will need to get a manual for learning now and future reference. The cars subsystems are not that complicated but taken together can be overwhelming.

hi there i am just learning about k-jet. you seem to have some good experience. maybe a dumb question, did you change the fuel filter? im thinking fuel pressure could build up but flow is very important here. is your fuel pump relay heating up? my k-jet car heated up and the car would die. my friend and 16 year volvo mechanic says the worst thing for k-jet is to sit. the bentleys manual calls for system line pressure (75 to 84 psi) or 5.2-5.8 bar. and residual pressure after 20 minutes (29 to 39 psi) to test the c.p.r. it gets a little involved. the bentleys describes this in pretty good detail. i hope i can learn from your post.