PROBLEM: 94 Ram 5.2L Not getting fuel / little if any pressure on the rail. Can't hear the fuel pump sound when I turn the key on. Engine will start if we give a shot of gas down TB and stay running at 2000-3000rpm if I keep working the throttle...let off and it idles rough for a second before it dies.

ATTEMPTED REMEDIES SO FAR:
1. Fuse and relay checked ok.
2. Replaced fuel pump...problem remains the same.
3. Removed and cleaned Throttle Body AND the IAC valve....problem remains the same.

Please RE with any suggestions....not sure if it's MAP, TP, IAC....how do I find the problem without going to the dealer?

 

I don't know if this has anything to do with controlling fuel to the rail, but you could try it:


Try testing the TPS (Throttle position sensor) with a digital multitester. It's the sensor on thedrivers side ofthe TB. You can get a digital multitester atan autoaparts store or even radioshack for like $20, just make sure it can read down to 1/100 of a volt.

Turn the ingition to on but don't turn over the ignition,backprobe the center wire of the TPS with the red probe, then connect the black probe to a suitable ground. It should be reading .75V(orvery close to that). If not, then you can either buy a new one, oryou can try to drill out the metal spacers that go into the torx screw holes with a 1/4" drill bit. Put some small washers on the ends so the screws have somethingto bite onto and tighten the screws back into the TB. Just before you anchor 'em down tight, twist the TPS around until the multitester reads as close to .75V as you can get, and then achor it tight. Put the air hat back on and test it out. If it works, you just saved $50.

 

I was out purchasing a throttle postion sensor while you posted....thanks for the reply though...the list continues to grow:

PROBLEM: 94 Ram 5.2L Not getting fuel / little if any pressure on the rail. Can't hear the fuel pump sound when I turn the key on. Engine will start if we give a shot of gas down TB and stay running at 2000-3000rpm if I keep working the throttle...let off and it idles rough for a second before it dies.

ATTEMPTED REMEDIES SO FAR:
1. Fuse and relay checked ok.
2. Replaced fuel pump...problem remains the same.
3. Removed and cleaned Throttle Body AND the IAC valve....problem remains the same.
4. Just replaced the TPS...problem remains the same.

 

are you getting fuel to the rail with the new pump ?
just a guess.. might remove the fuel rail and injectors and check for rust or other debris and clean it out with carb cleaner

 

The pressure on the rail is low, i've been checking it by depressing the needle valve on the railand observing the amount of fuel that (barely) comes out....other posts have stated that there should be around 45 psi and it should spray out when this needle valve on the rail is depressed....my next guess is to buy a new IAC valve...even though I cleaned the old one.

If that doesn't do it what else could it be?

 

Parts have been known to be bad out of the box especialy electronics. I know it is a pain to replace the pump but if you can't hear it kick on and you still have low fuel pressure I would take it back.

 

MAGICDSSMAN, thanks for the input....I'm going to try all other avenues before I pull the pump out and return it. I guess the next try will be a new IAC valve. Besides that, does anyone have any other ideas before I try taking the pump back to the parts store???

PROBLEM: 94 Ram 5.2L Not getting fuel / little if any pressure on the rail. Can't hear the fuel pump sound when I turn the key on. Engine will start if we give a shot of gas down TB and stay running at 2000-3000rpm if I keep working the throttle...let off and it idles rough for a second before it dies.

ATTEMPTED REMEDIES SO FAR:
1. Fuse and relay checked ok.
2. Replaced fuel pump...problem remains the same.
3. Removed and cleaned Throttle Body AND the IAC valve....problem remains the same.
4. Just replaced the TPS...problem remains the same.

 

PROBLEM: 94 Ram 5.2L Not getting fuel / little if any pressure on the rail. Can't hear the fuel pump sound when I turn the key on. Engine will start if we give a shot of gas down TB and stay running at 2000-3000rpm if I keep working the throttle...let off and it idles rough for a second before it dies.

ATTEMPTED REMEDIES SO FAR:
1. Fuse and relay checked ok.
2. Replaced fuel pump...problem remains the same.
3. Removed and cleaned Throttle Body AND the IAC valve....problem remains the same.
4. Just replaced the TPS...problem remains the same.
5. Blew 30 psi air down the inspection valve on the fuel rail while the pump was disconnected, in hopes of dis-lodging any junk in the fuel line, then, replaced the "new" fuel pump with another "new" one....Now I CAN hear it prime when I turn the key on....but...It still won't start unless I pour some fuel down the throttle body....its sitting there, dead in the garage right now with the charger on it.....pretty sad deal....thinking about having the local mom & pop shop come and get it, cuz the days of "back yard" are turning into guessing games that only the big boys can afford....

ALL RECOMMENDATIONS WELCOME.

 

i still say remove the fuel rail and injectors.
see this.
http://dodgeram.info/Engine-Gas/Inje...ace/index.html

 

did you yank the plugs and check for gas oder? could be an injector is stuck open and your spitting out fuel which is causing low pressure.