[ssmonty]

Hello everyone,
A friend has a 3.8L fuel injected Buick V6 that sometimes refuses to start. It turns over fine with the starter, but never hits a lick. Come back later and it may fire right up. He replaced the ignition module under 3 coil packs. He said that jumping it off seems to make a difference sometimes. We used a timing light while turning it over and no flash from the light.Any ideas?
ssmonty

 

[T-bucket23]

if this is a mid to late 90's vehicle, they had huge issues with the ground block in the drivers side front door sil. The other common issue would be a crank sensor. You can validate the crank sensor with a good scan tool. Check for pulses.

 

[fast68]

just had one of these same engines doing the exact same thing and it ended up being the fuel pump dying

fuel pressure was just under the minimum it needed to be in order to start.

i would check this also.

got a 96 one in the shop now we are replacing the engine in because it seems the upper intake cracked on it originally and now the rod bearings are screeching and knocking

im pretyt usre the intake caused water in the oil and washed the bearings and now causd the bearings to spin

cracked UIM is a very common issue on these series II 3800s we have replaced many

good luck

 

[ssmonty]

Thats for the replies fellas!
He couldn't wait and got it towed to the shop. Turns out it was the crank sensor. We didn't have any kind of scan tool to check it with anyway. You nailed it Chet! Thanks again!

PS I feel like a moron when it comes to working on todays cars, and I was an electronic tech. for 20 years. I mean in the old days you could get it running with basic hand tools, but today you have to have all kinds of special expensive diagnostic equipment who's cost is prohibitive for a shadetree do it yourselfer. I'll just keep my old antiques. Call me a geezer.
ssmonty