Hi,

I have a 1994 Volvo 850 2.5 auto, which I've owned for the last several years. It was always very reliable but two years ago was taken off the road. It was started regularly and started first time every time. However this year I did some work to get it ready for mot, replaced the wheels, new catalytic converter and also gave it a service.

But now it's developed a problem and for the life of me I can't work out what's going on with it.

I start the car and it starts off fine, but it has no power, even with foot to the floor on private land it was quicker walking and the engine nearly stalled several times.
I replaced the spark plugs as I thought one might be dodgy. However that didn't work and now the car can't be moved, it starts, idles lovely but within a minute then starts to vibrate badly and then the engine cuts out. Press the accelerator down and it sounds awful, no power and just really bad sputtering. Starts again, and same thing happens.

Don't really want to sell this one on as a project. Its been in the family too long and I'd hate to see it go.

Any help with this would be great.

Thanks.

Also just want to add I have changed the fuel pump and the problem still exists.

 

Check your fuel pressure. Look at the spark plug wires in the dark or just replace them.

 

there's a date code on the wires and if they are over 5 years old, replace. If in doubt, do a "stage 0 " tune up. Replace the plugs (go OEM or simple copper cores - older cars don't run better on the Iridium etc), replace the wire set, the cap and the rotor. Note it is possible to get the distributor cap off without removing the airbox, but moving the airbox out of the way is way easier... After that, you can check the fuel pressure using the shraeder valve on the side of the fuel rail. Pretty sure RobertDIY posted a vid on how to check for fuel pressure issues. Usually on the 850s the fuel pumps wear out and cause similar issues.