Cold weather starting

DAVE COOK

MEMBER
GMC

My 1989 Pontiac Bonneville has a cold weather problem: It won't start, it backfires & won't run:
This is one of the nicest cars I’ve ever owned. It currently sits at 370,000 kilometres and I can see driving it past the 400k mark.
This winter a problem arose with cold weather starting. When the temperature hits minus 18C (0F), the engine turns over fine but the car reacts like it’s being flooded. It just about starts then violently backfires and the engine stops dead. I’ve ruled out all of the following (a costly venture to be sure) -- heat sensor, crank sensor, computer, timing chain, ignition module, injectors.
My mechanic is baffled. So am I. Any ideas. Please?
Dave Cook, cecild@shaw. Ca

2 Replies

POWER6

MEMBER
2 POSTS

I have a 1990 bonneville SSE. Same problem, no one has any idea, and the engine light does not come on. I have to plug the block heater in for at least a half hour to get it started. So you would think that it has something to do with a temp sensor. I have replaced one of them, but it turns out I replaced the one sending signal for the gauge only! If you have any luck with your car, let me know, I will do the same for you. Good luck.