91 5.8 lacks power

[Rich McIlroy]

Hope you all can help, I have a 91 full size (130,000 miles) with a 5.8 EFI that last year when towing our camper started to act up after it got good and hot. (And of course we had to wind up being out on the hottest weekend of the year) It started popping out the intake which to me signalled a timing issue...i managed to limp home by feather footing it and checked it and found alot of slack in the timing chain but it was running fine without the load on it i left it go and it performed fine for the little driving i used it for over the winter. This spring it decided to go on a rampage and took and alternator,battry,started and while i was at it i replaced the timing chain,t-stat and water pump while i had it all apart. Now it is still not behaving correctly the timing is set correctly but my best description is that it is not advancing the timing...still get the pop from the intake from time to time especially when towing the camper, loses power on the bottom end doesnt feel like it has any torque but once it gets up to highway speed it seems fine to cruise along unless challenged by hills. Any ideas? Pretty much at wits end with this thing and dont want to get rid of it but cant keep throwing parts at it and i am out of ideas.

Thanks,

Rich M

 

[89Bronco58]

have you done a compression check and tune up?

 

[Rich McIlroy]

have you done a compression check and tune up?

Tune up yes...compression check...not yet

 

[89Bronco58]

well if it has a serious compression loss that would be a reason it lacks proper power, and my old 302 used to have a poping sound when i would decelerate then hit the gas again, i think it was some sort of misfire due to the slack in the timing chain, only thing i can think of is maybe you lined the timing marks up wrong and in turn even tho the distributor is in the right place the cam/crack timing is off

 

[Rich McIlroy]

well if it has a serious compression loss that would be a reason it lacks proper power, and my old 302 used to have a poping sound when i would decelerate then hit the gas again, i think it was some sort of misfire due to the slack in the timing chain, only thing i can think of is maybe you lined the timing marks up wrong and in turn even tho the distributor is in the right place the cam/crack timing is off

I'll do a compression check over the weekend and see what that yeilds...i am suspecting i have a blown head gasket. Could this be contributing to this condition? As far as timing goes i feel pretty confident that it is lined up correctly. Timing checks out okay plus before and after i really didnt notice a whole lot of difference in its behaviuor. It seemed better for a little while...like the computer was relearning...then it back slid.

 

[89Bronco58]

if you had a blown head gasket yes it would be loosing compression, but most likely burning antifreeze and smoking pretty bad...youd notice it