My whole car (89 740) is shuddering at idle, I cant go above 20mph (plus it sounds terrible). I put some fuel injector cleaner in the tank yesterday.......this morning it wont even start? it was running great before I put it in. help please....im lost

 

so it has a spark, cam turns, sputters a tiny bit like its going to start

 

Go to www.stepbystepvolvo.com for free guide to 740 no-starts. Could be a main fuel pump or radio suppression relay. Do the tests in the guide.

 

it ended up being the fuel injector resistor pack lol