Good afternoon. I recently bought a 94 Ford F-150 XL that has been sitting for a while outside. It was thought to just be an exhaust issue. It ran ok for a day or so, then broke down losing power requiring to be towed four different times over the weekend, has been checked by two different shops with no definite culprit. I have no mechanical training or experience but have wanted to learn and start. My question is how do I begin to troubleshoot this truck or any vehicle built before the code scanner port implementation? After doing some initial research, I have a list of possible things to do such as: Tune up with new plugs, wires, and distributor; replace all fuel injectors (one shop stated it might be off on 4 & 6) and overhead gasket; check and remove catalytic converter and instal new one or go to a straight pipe exhaust; replace fuel filters and drain fuel from both tanks (I’ve already used two doses if fuel injector cleaner); MAP sensor; Oxygen sensor (s); and replacing vacuum lines. I’ve bought the Haynes manual for the vehicle and an Auto Repair for Dummies and willing to try and tackle this but there doesn’t seem to be a reference for a step process for troubleshooting as a process of elimination to find actual issue. I will more than likely do all listed work in time to ensure top performance but need to get this truck up and running for now. Sorry for the short book but wanted to be thorough with available info. Any advice will be greatly appreciated, Thank you.

 

Welcome to the site..

How many miles on the truck?
Well, I'd try and focus on the 'why', meaning, what you state about it losing power.

Running 'ok' for a day or so, does that mean it ran good/fine with no issues, or, 'just ok' meaning not perfectly but somewhat drivable? Is the check light coming On, intermittent or steady illuminated. If so, that's a good direction to investigate in a diagnostic path to take.
Generally, ignition (spark) related issues will cause misfires, buck/jerk. Ignition module, pick up coil can cause a stall, no start but normally ignition related parts won't cause power loss or a bogging down situation, and eventual stall if that's what your experiencing. (?)
Fuel related, plugged/restricted catalytic converter can cause hesitation, power loss most often noticed under higher power demands, unless severe. Insufficient fuel delivery can cause a flat throttle, bog, with no CEL, but most often the idle would be stable. Injectors can cause misfires like ignition related do, can be random in nature, or steady, in high and low end ranges, but most often not a stall condition, bog. Certainly if a few cylinders are not contributing enough, or at all, drivability would be very poor.
Power loss, yes, and if the fuel quality is poor and/or contaminated certainly a possibility. Checking the fuel filters contents may prove out fuel supply concerns..
If the truck will idle, even forced, a simple pair of high tension pliers removing a wire at a time can help identify which cylinder/s aren't contributing, be it due to spark missing or weak, injector issues, or compression below spec. A comp check straight off isn't a bad idea to get a general idea of base engine health..
Checking for fuel pressure and spec volume at the fuel rail will normally take fuel delivery concerns off the table, and if a test gauge installed during an engine stall,, can help point to pump issues.

Can you expand of what happened or what you experienced during the power loss to the stall out?. Being it wouldn't restart would seem ignition or fuel related.. Most engine management components would be cause for a CEL, possible no start, but more so poor idle and drivability...

 

I got a 2006 f-250 I was building 13 to 14 psi boost with y pipe leaking bad took got it fixed it’s not leaking did smoke test has a new map sensor took off hose and blew air to see if it would read on my program on laptop map hose is good new ebp sensor and still no boost and on computer vgt’s are good but map isn’t reading on it any thing I’m over looking??

 

Did you get a chance to check the "Charge Air Cooler" ? Possible restriction ?