88 f150 problem
 

I have a 1988 F-150 XLT with the 300-6 engine.
Just recently my truck has started to have a low idle bog and a slight miss fire, I've replaced the throttle position sensor, map sensor and idle air control valve and it still seems to run a little rough on acceleration. I've cleaned the throttle body also. Any ideas that could help?

Spark plugs, plug wires, rotor, and cap?

I'm assuming there are no codes? Put a couple bottles of chevron techron in the gas. Do a compression test.

Don't forget the fuel filter too.

F150
 

Yeah I replaced all those, I even cleaned the throttle body and ran some seafoam spray through it, it still seems to have a rough acceleration

What were the results of the compression test?

F150
 

I actually didn't do the compression test, didn't read that part, just found a way to test obd1 codes and I don't know how to decipher it.
it was #23522352163336333. I don't know if that helps or not

That's not a OBD1 code. OBD1 codes in 1988 are all 2 digits.

http://www.thorssell.net/hbook/eectest.html
http://www.thorssell.net/hbook/2digit.html

Instead of using a meter, you can count flashes of the check engine light, you just need a jumper wire.

*DO* a compression test.

Did you put Techron in the gas? If not, do so. If so, how many miles have you driven it since you put it in and how much did you put in?

Roughly, the throttle position sensor is out of range, the egr is not opening, most of the numbers are repeated codes so you need to disconnect the battery for an hour and reset the system. I would start by looking for any vacuum leaks and small rubber hoses that are cracked or aged. Don't find any leaks, compression check will tell the tale.

F150
 

Okay thanks I will try all of those. Yeah, with the code I realized I wasnt reading the flashes right. I didn't use techron but I have been using seafoam in the tank for about 20-30 miles approximately.

Seafoam in the gas won't help, that's primarily for carbureted engines and won't clean fuel injectors. Seafoam is also hard on the catalytic converter. Run that tank out and use Techron next tank.