I have a 350 yukon 1997 with 54 000 miles
I tow a 3500 lb boat
After a long uphill pull at 50 mph, there is a heavy engine miss when I come off the throttle and then open the throttle to continue at speed. There is no miss as long as I don't back off and then come back on.
New platinum plugs New spark leads new fuel filter new pcv valve no change.
This weekend a flashing check engine light added to the fun but under moderate load, no light and it went off as I continued under moderate load.
There is a little induction rattle at light load.
I'm wondering if the dealer (ach) didn't seal the manifold properly when they replaced the intake manifold injector body gasket and somehow a vacuum leak is causing preignition in the manifold??
I hate to go to the dealer with an intermittant fault
any ideas?
markdpro