backfires only when throttle is snapped

[blue83ranger]

Last sunday i bought an '87 ranger 2.9 5 speed 4x4 and it has a few issues. i got it to run on all the cylinders but one problem it has is that it backfires in the intake only when the throttle is open very quickly, otherwise it doesn't do it and it only does it once. I already had to move the plug wires around to their correct locations and i rechecked a few times to be 100% sure they were right. I also had to pull the dist. and turn it 2 teeth because it was off. I checked the timing with a light with the spout out and it was where it should be. It also cranks over like the timing is advanced to much and it fights itself to turn over but the timing is set right. and it does have exhaust leaks that i'll fix soon. I know what the codes i got mean but if it helps anyone here they are.
KOEO
34 which is the EGR signal is to high
KOER
42 EGO rich
32 EGR signal to low
13 RPM out of spec
25 no knock signal during test
continuous codes
14 PIP Eratic
53 TPS signal to high
32 EGR signal to low

I know someone messed with the throttle stop screw so that would get rid of code 13 and 53. and the oxygen sensor wires were melted to the exhaust, i didn't fix it yet but i would guess that would fix code 42. Does anyone know how to tell what wires go where? the plug completely melted so i don't know what wires go where, although i do have an '86 and '88 2.9 rangers i could look on. and with the egr codes i took the egr off and it is completely closed so i just unhooked the vac. line at the intake and capped it. So, any ideas why it pops or why it doesn't turn over smoothly?

 

[RustedRanger]

One problem is that the "throttle stop screw" is to set the TPS voltage. Without that set right the computer doesnt know what position the throttle is in. Also make sure to unhook the battery after any changes to reset the computer.

 

[dave2575]

Blue it sounds like the backfire could be timing related, check the dist. cap for cracks, maybe a plug wire is arcing, or check for vacuum leaks, and you checked the dist. and had to moved it 2 teeth, maybe the timing gears lost some teeth or the belt slipped. You might be able to try and fix all the codes and end up getting rid of the backfire to and I will check on the o2 sensors wiring for you after work. keep us informed, and good luck. p.s. sorry to jump in here but I know that my throttle stop screw has been moved also. Do you guys know how to get it back to the factory setting? thanks Dave.