1996 4.0l OHV Can drive for maybe 10 miles till I have loss of power, wont start

[Keetonmx]

Hi I just bought this 2dr 1996 Sport 4.0 ohv. some background info, skip down if you want. it has 134k miles, has maintenance records back to when they bought it. The truck was given to his son who I think started doing IMO (but, I'm also uneducated in this) dumb modifications. He wired a stereo in wrong so the screen stays on 24/7, led backup camera stays on, sub/amps and wiring everywhere. parts are grounded, might be the starter, throttle body. There is an aftermarket intake that I think is just sucking in hot air. There's also a tube from what I think is the valve cover to a little mini air filter, but I thought it should be attached to the intake?

Drove fine first day I bought it, go figure. 2nd day I went for a drive and it was good for about 10 miles before slowly losing power and dying. I had to press the pedal real hard to move while it was losing power. I got a tow and bought a new battery because found the old one said BAD and everything seemed to work better. drove fine the 2 miles to my unit. I went for another drive few days later and same thing happened, lights still worked. starts right back up a few hours later and we drove it on the flatbed. checked all hoses, coils, coolant, radiator gets really hot on the top of the aluminum, hose on the left feels warm and top/bottom aluminum tubes on the right feel the same temp, fan runs, heat works, compressor on/off. Is it normal to have to press the pedal with some pressure on these? Seems to get up to speed fine when first driving, even when I stepped on it, shifts fast/smooth and goes into reverse fast. oil looks clean, coolant clean. Trans leaked a little after sitting in storage for a couple weeks, I checked fluid and it was a little low, so I filled it. I checked fuses and swapped the fuel filter fuse. haven't done compression or checked spark plugs. have gas. took battery off after it died, and it tested at 13.5v. throwing no codes, haven't had it checked anyways.. but engine light comes on when in ON position. after it dies on me, tries to start and does but makes noises then dies eventually doesn't try at all but gauges shoot up for half a second, tried this with my jumper hooked up. Oh it does shake sometimes, mostly after driving it but stops in park.
I didn't notice at first, but they took off the cat-back exhaust so there just the cat there and no muffler or resonator(?) So I was thinking of getting one from MAC Auto Parts on EBAY, anyone tried?

thanks

 

[410Fortune]

check fuel pressure
sounds like a dying fuel pump
they work great when cold, start to heat up and fail to deliver fuel

the cold air intake is not a good setup, but it wont cause these issues
yes the crank case breather can be plumbed back into the intake tube, having it breathe through a filter wont hurt anything and it wont cause these issues, but around here we like a good stock airbox with stock intake tube over that "mac cold air intake" setup. That air filter is sub par, the metal tube actually soaks up heat and the air filter is sucking hot air from the side of the engine, as well as sucking up turbulent air from the cooling fan.
Stock intake is better
Fix the stereo and camera wiring
Check the firing order on those plug wires 1-2-3-4-6-5 is how they are wired, it is written on top of the coil pack

Your issue is not caused by the faulty radio wires or crappy intake setup, it is most likely fuel related
Especially if the truck sat for any period of time prior to you getting it....fuel pumps do NOT like to sit
We use bosch pumps here pretty much only, unless you cannot get your hands on one (covid supply chain issues) then ac delco, carter, carquest brand are decent options...stay away from cheapo parts store pumps like airtex or duralast IMO

You need a new pump, strainer and filter
when the truck dies check fuel pressure should be 36 psi +/- at the rail

I'm wondering what's up with the big red wire going to the alternator and the big red wire to the drivers side of the intake manifold. Looks like somebody was trying to upgrade the charging system?? make sure it was all done well and good connections made

 

[C420sailor]

I’d still fix the stereo issue ASAP. That is going to crush your battery, which will cause other issues.

 

[Keetonmx]

check fuel pressure
sounds like a dying fuel pump
they work great when cold, start to heat up and fail to deliver fuel

the cold air intake is not a good setup, but it wont cause these issues
yes the crank case breather can be plumbed back into the intake tube, having it breathe through a filter wont hurt anything and it wont cause these issues, but around here we like a good stock airbox with stock intake tube over that "mac cold air intake" setup. That air filter is sub par, the metal tube actually soaks up heat and the air filter is sucking hot air from the side of the engine, as well as sucking up turbulent air from the cooling fan.
Stock intake is better
Fix the stereo and camera wiring
Check the firing order on those plug wires 1-2-3-4-6-5 is how they are wired, it is written on top of the coil pack

Your issue is not caused by the faulty radio wires or crappy intake setup, it is most likely fuel related
Especially if the truck sat for any period of time prior to you getting it....fuel pumps do NOT like to sit
We use bosch pumps here pretty much only, unless you cannot get your hands on one (covid supply chain issues) then ac delco, carter, carquest brand are decent options...stay away from cheapo parts store pumps like airtex or duralast IMO

You need a new pump, strainer and filter
when the truck dies check fuel pressure should be 36 psi +/- at the rail
View attachment 448484

I'm wondering what's up with the big red wire going to the alternator and the big red wire to the drivers side of the intake manifold. Looks like somebody was trying to upgrade the charging system?? make sure it was all done well and good connections made

It did sit for a while before he sold it to me..I'll check fuel pressure and firing order here when I'm back in town. I really appreciate your advice man