That was my thought too. So, I put in a new timing chain last week. It was bad. A lot of slack. I thought it might have jumped a tooth or two, but it didn’t fix the problem.

 

I replaced the intake manifold and plenum gaskets. It runs a little better but the problem is still there. It starts, accelerates and runs smooth for about 20-30 seconds. Then it starts run rough and stumble. If I let it try to it idle, it surges from 750 to 1200 RPM, gradually decreasing RPMs as it surges until it dies. I also replaced the coil.

Now I’m leaning towards the fuel pump. The first time I measured the fuel pressure it was 40 psi and steady. The next time it was 20. The third time it was 35. The fuel pump is about two years old but I have heard they are not too reliable.

 

Do you remember what brand pump you installed? Some folks like to buy the cheap one, (Airtex, I am looking at YOU!) then they get to replace them every six months or so...... Can you leave the pressure gauge on there while its idling, and watch what pressure is doing when it starts to screw up?

 

I’ll do the pressure test today, see what it reads and if it jumps around.

I took the bed off to replace the fuel pump last time. Anyone find removing the tank easier?

I can’t remember the brand fuel pump I put in. Any recommendations?

 

Depends on how much gas is in it. I always see them fail shortly after a fill-up, so, lifting the bed is 'easier'.

Delphi, or Denso pump. I believe they are OEM. Yes, they are more expensive.

 

I had problems with my 94 and broke the rollover valve when I put in the Airtex. I ended up getting a used one from a 96 V8 I think it is. I put it in 7+ years ago and its fine. I found out how to fix the rollover valve in the FAQ section so I did that on the airtex and have it for reserve now.

 

I checked the fuel pressure again.

When I started it up the pressure was 42. It ran fairly well. It would accelerate.

Over a minute or so, It slowly dropped to 40, whereupon the engine started to stumble a little.

It continued to drop over a couple more minutes, the stumbling and surging getting progressively worse, until it died at 36 psi.

This was all at idle.

The pressure didn’t bounce around. It was a steady decrease.

 

I have old links to some TSB's about the fuel system. Dodgeram.org is no longer online so there is no point in sharing them. Wait a minute.....Thought I could findit on the Wayback machine but the links I have do not show the fuel TSB I remember.
What I remember is it talked about the connector at the pump not making connection and or one of the wires failing. The wire fix was to run a new wire.
That sounds like a dying pump.

 

I replaced the fuel pump with a Delphi. That didn’t fix it.

I tested the fuel pressure again. I attached the gauge to the port on the fuel rail and positioned the gauge against up the windshield so I could watch it. The truck started up and idled pretty well. I wanted to look at the throttle body so I got out, with the truck still running, and looked in the engine bay. The gauge fitting had unscrewed a little from the port. Gas was pouring over the driver’s side of the engine and onto the garage floor. I rushed back in and shut off the engine. Just then, the engine caught fire. Fortunately I had a fire extinguisher about ten feet away and put it out.

I was sure I had fried the wiring. I took off the fuel rail and injectors. Then took the wiring harness out of the truck and examined it on the work bench. A few sections of the outer covering (plastic, corrugated, black conduit) were completely melted but none of the wiring was singed our melted, except the connector wire to the IAC. I replaced that. While the harness was out, I did a continuity test on every connector back to the PCM plug. Every connector was good. I had to replace vacuum lines to the evap purge solenoid, EGR and HVAC controller. They had completely melted. Then I had to clean up all the fire extinguisher dust.

So, I had everything fixed and put it back together this morning. I started it up. It still has the same problem, loss of power, surging and eventually dying at idle. But, I finally got a check engine light. The only code that came up was 27, injector control circuit, output driver does not respond properly to the control signal. The injectors are only about a year old. I kept the old injectors. I put new o-rings on them and put them in. Still got a check engine light and code 27. The code doesn’t specify which cylinder has the problem. It could be any one, or all eight. I checked all the fuel injector connectors with a 12 volt test lamp. They are getting power. I checked all the injectors and cleaned them again. They work fine.

Any advice? Other than don’t light your engine on fire again?

Now I am thinking I could replace all the fuel injector connectors. Or, it still might be the PCM. Starting to get frustrated now.

 

Someone smarter than me will come along with good advice but when I hear “output driver” it sounds like PCM. But that might not be as scary as you think. With an OBD1 it’s kinda like just another component…if an OBD1 is what you have (I don’t know much about OBD2).

BTW, good save on that fire. Fortunate you had that xtinguisher and the reflexes to put the fire out as quickly as you did. Nice job!