Hi everyone

I have a Volvo 240 1984 Intercooler Turbo. This came with a problem in the fourth cylinder, and when I removed the head, I realized that it does not bring the original engine that should be the b21ft, instead it brings the b230ft. This has the k-jetronic injection system.

I already repaired my head, I changed my fuel filter, vacuum hoses
, new fuel injectors, but I'm having low gas mileage. I'm thinking that maybe I should change the fuel pressure regulator or increase the pressure.

Does anybody have any suggestions?

 

does this car have a lambda (oxygen) sensor ? connect a volt meter set to a low volts scale between the oxy sensor signal to ground, run the engine til its warmed up, and you should see the voltage swing between around 0.1-0.3V and 0.7-0.9V then back, every few seconds. the exact voltage isn't important, its only important that its moving above and below 0.5V every few seconds. if it stays low or high, then the car is not in balance, and is running too rich or too lean.

lousy mileage (burning too much fuel) would suggest its running too rich, so you would want to lower the system pressures, but thats tricky. running too lean can burn pistons out.

K-Jet cars don't have a simple fuel pressure regulator, the whole fuel distributor is like a dynamic pressure regulator that sets the pressure based on airflow, more air == more pressure.

its been so long since volvo sold any K-jet cars, that hardly anyone alive remembers how to deal with them. all of the B230FT turbos were LH electronic injection.

 

Very hard to solve a problem like this without some extensive hands on work... I can give you all kinds of worthless tidbits about this or that system but in the end you need some mechanic who knows vintage Volvos and is not afraid of experimenting. Don't waste money on a new fuel pressure regulator, that won't help.