89 Ramcharger
 

Hi aii,
a buddy of mine has a 89 ramcharger with 5.2 throttle body. he has recently started using as daily driver. it sat for about three years first he drained feul tank put a few gallons of fresh gas after a few mile s then changed fuel filter, plugs ,wires ,cap and rotor and the pickup assembly that goes under rotor , and new coil.. he drives 38miles oneway and sometimes it runs good other times not,. he stopped by yesterday and at idle it runs very smooth . little amount of gas stumbles for a second ( for those who remember Carbs when the accelarator pump( the rubber gasket) was starting to go bad). then as throttle is increased ok to half throttle, then at full wide open it goes to a bog like its not gettig gas or not taking gas kinda like waaaaaaaaaaaaaaaaa then picks up for a pulse and back to the bog sound as you start to back off it smooths out at about half throttle ........ Any ideas will of great help .thanks in advance ........lj dont have scanner to hook up but the switch means of gettig codes show 12,37,15,23,14 thanks john

First thing to replace would definitely be the spark plugs. If that doesn't completely solve the problem, run some fuel injector cleaner through it. I prefer the Sea Foam brand. Also, it sounds a lot like the timing is off. What you need to do is have someone in the truck pressing the throttle to where it runs rough and another person twisting the distributor cap until it runs like its supposed to.

A bad CAT can cause that - I'd check on that and the o2 sensor.

12 - Battery or computer recently disconnected
37 - lock up torque converter error
15 - No speed/distance sensor signal
23 - Incoming air temperature sensor may be bad
14 - MAP sensor voltage below .16V or over 4.96V

12 and 37 are normal. I would say 14 is your big issue.

Might try a new sensor. Or do the test on the existing sensor to see if its bad, or you got bad wiring.