First off, I'm excited to join the 460 Club and build my 460 knowledge with the help of the skilled people on the website. I just want to start out saying that I am by no means a mechanic. I have very little experience under the hood of a gas motor but owned a diesel truck for the last two years (2005 Harley Davidson F-250 with the amazing/dreaded 6.0
) up until sold it and bought this truck. That being said, I am a mechanical engineer. So the lack of hands on experience I have, I can somewhat make up for with my understanding of concepts so bare with me.
I'm having issues with the timing of my "new-to-me" 1988 F-250 4x4. It has the 460 EFI with the ZF-S542, and I can not get the timing right. The truck is completely stock except headers and exhaust, and I cut the intake horns.
The truck seems to have decent power up until about 3000 rpm and then it just seems to fall on its face. Now I've read that the cam kind of hinders this top end power, but I really felt like it was falling TOO much just to be the cam. After I did some research and got to looking around and piddling with it, I noticed that there was no SPOUT connector plugged in to the plug.....so being as I did not have a connector, I decided to throw a 20 amp fuse in the plug and see what happens. When I plugged the fuse in, I noticed the timing advanced so I was assuming that it would run a little better....boy was I wrong
. I hit the throttle from under the hood a few times and found that it would sputter and pop real bad, almost like spark knock. I attempted to drive it down the road and that just was not happening.
So I borrowed a buddy's timing light and decided to check what the base timing was actually set to. I bumped my starter until the markings on the balancer were facing the ground and marked the timing marks with a white paint pen, pulled out the fuse I placed in the spout plug, and proceeded to check the timing. Come to find, the base timing was set past 30 degrees, close to 40!! Now like I said, I am NO mechanic....but this just does not seem right. I tried setting it back to the 10 degree base timing and when I plugged the fuse back in, same thing-running like crap. Pulled the fuse, set the timing back to the original 30-40 degrees, runs just like it did when I bought it.
I search forum after forum, and could not find anything that helped much. What I did find led me to believe I have some sort of electrical problem. I decided to replace the MAP sensor first, as well as the IAC valve. I ordered a new TPS sensor, but was unable to removed the two screws holding it in (I have ordered an impact driver, gonna attempt that this week). I also ordered a new fuel pressure regulator, at this point I am just waiting until I get a chance to really dive into that (I have FPR with the 3 screws on the bottom of the regulator, should be fun). I have not rechecked the timing since installing the MAP and IAC, I was really wanting to at least replace the TPS and FPR before I did, but I may go ahead and check it this afternoon. My real concern is that this is going to be an EEC issue and I haven't even been able to find one for sale
I have also ordered a OBDI code reader to see if any codes are being thrown, but I have no check engine light on so I am concerned it wont have any codes if the light is not on. If anyone has any advice on my problem or the direction I need to head to fix this, I would greatly appreciate it!!