3.0 Misfire
- Thread starter Stan Reeves
- Start date
Stan Reeves
New Member
I did a leak down test on # 3 cylinder today and it passed in flying colors. I pulled the plenum again and looked for cracks in the plastic but it looks great. I didn't think it was a valve because it runs great at startup. It is when it idles after warm up I get a misfire.
Stan Reeves
New Member
Well, I finally fixed it. After putting a LOT of money and time I knew it was not a valve after doing a leak down and compression test and it would run perfect until it warmed up and I could drive it a hundred miles with no codes, it was when I stopped at a red light or a stop sign it the check engine light would come on.
I noticed that after warm up it was only idling at 450 to 500 RPM’s and p0303 would come up.
I looked at the throttle body and there was no screw to adjust the idling, mine has a rivet that cannot be adjusted,
The end of the rivet that contacts the stop on the throttle body was worn down and letting it idle too low. I tested it by gluing a dime on the stop on the throttle body that rests against the rivet at idle and it increased the idle up to around 900 RPM’s. I drove it about 200 miles and it ran perfect. I pulled the throttle body and drilled the rivet out and put a screw that I can adjust. I have driven it over 500 miles since I added the adjustment screw and it runs perfect.
I noticed that after warm up it was only idling at 450 to 500 RPM’s and p0303 would come up.
I looked at the throttle body and there was no screw to adjust the idling, mine has a rivet that cannot be adjusted,
The end of the rivet that contacts the stop on the throttle body was worn down and letting it idle too low. I tested it by gluing a dime on the stop on the throttle body that rests against the rivet at idle and it increased the idle up to around 900 RPM’s. I drove it about 200 miles and it ran perfect. I pulled the throttle body and drilled the rivet out and put a screw that I can adjust. I have driven it over 500 miles since I added the adjustment screw and it runs perfect.
Stan Reeves
New Member
I finally found out what was really wrong with my Ranger. I took it to Mexico and got a top end rebuild. Ford had never put a bolt in the end of the exhaust manifold right by number 3 cylinder.
The mechanic that rebuilt the heads called me and showed me the # 3 exhaust valve. It was slightly warped. He said it was probably because the factory forgot to install a bolt in the exhaust manifold, he showed me the rusty threads, there has never been a bolt in it. When I bought the truck it had 4 miles on the odometer. It runs great now and the top end rebuild only cost me $150
( I supplied all the gaskets, oil, filter and antifreeze )
The mechanic that rebuilt the heads called me and showed me the # 3 exhaust valve. It was slightly warped. He said it was probably because the factory forgot to install a bolt in the exhaust manifold, he showed me the rusty threads, there has never been a bolt in it. When I bought the truck it had 4 miles on the odometer. It runs great now and the top end rebuild only cost me $150
( I supplied all the gaskets, oil, filter and antifreeze )
Stan Reeves
New Member
It sure is nice to have it running right again, after the top end rebuild I am getting 22.6 miles per gallon.
DeanMk
Member
That's Smiles per Gallon, my friend. =)