Turbo Lancer problem

[rare_ram]

Last week I replaced my fuel pump after a surging issue. Then we had 3 rainy days that had the car being hard to start, which I attributed to a loose distributor cap. Yesterday before I had a chance to look at it the car started only going 25-30 mph and if I tried to push it it'd backfire out the tail pipe. Today I got time to look at it and the cap was loose. tightened it and no effect. So I got a new cap and rotor and even swapped in a different HEP. still no better. Any ideas?

[GLHNSLHT2]

make sure the hall effect pickup metal is tight to the plastic that holds it to the shaft. What year Lancer? Mine would die in the rain. after a while it wouldn't start, LM had gotten wet and fried the board.

[going4speed]

Any codes?

Possible vehicle speed sensor or vacuum issue but need the codes to see if the car is telling you something first.

[rare_ram]

86 Lancer, no codes.

[rare_ram]

Just to be clear. Drives/pulls great to around 25-30 then nothing. Push the gas and small backfires from the tail pipe. let the gas off and runs fine but no faster than 25-30. Probably at a certain RPM, but tach doesn't work. A local friend thinks the timing belt skipped a tooth. It's probably the original with 83K on it.

[going4speed]

Check the vacuum lines to the map sensor for leaks. This sort of sounds like map sensor limp home mode but odd that it has yet to set a code for that as those codes normally set pretty quick.
Have a timing light? Set the timing to zero then point the timing light through the hole in the side of the timing belt cover. If the oval mark is in the middle of the window your timing is fine. At 83k you will need a timing belt at some point but the validation step should help diagnose the current issue.