Hey gang,

I’m working on a 91 4.9L in-line 6. I’ve been working on an ignition problem for quite a while and I traced it to the pip sensor in the distributor. After changing the distributor I still wasn’t getting a spark. I had a friend turn it over while watching the distributor with the cap off and the rotor wasn’t spinning. Took the distributor back out and looked down in the hole while the other guy cranked it and there’s nothing spinning in there. I know it’s supposed to be, but that’s sort of the extent of my knowledge. I think that goes to the oil pump, but I’m not sure. What next steps would you guys take? I’m thinking about dropping the oil pan and looking for a seized pump or something broken. Is there anything else I should look into?

 

The distributor drives off of the camshaft. If the camshaft is not turning, most likely the plastic composite timing gear that drives the camshaft has failed. My best guess.

 

Yea if you can look down the hole in the valve cover see if your rocker arms are moving

 

I have to wonder why some last, and some don't. My engine has a million miles on the timing gears, and it runs like new. My other '95 4.9L doesn't even have 200 Kmi yet. This one had a lot (I don't remember exactly how many), and it had been abused & neglected, but it's still running OK more than a year after this repair:


(phone app link)

 

Indeed. I’m new to this truck and I’ve only had it for 4-5 months, but the odometer just turned over on me before it broke down so who knows how many miles are one what parts. I’m in for some fun with this thing.