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Swapped a 98 5.9 Mag into my 95 2500 4X4 -- Backfires
2nd Gen Ram Tech1994-2001 Rams: This section is for TECHNICAL discussions only, that involve the 1994 through 2001 Rams. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.
Swapped a 98 5.9 Mag into my 95 2500 4X4 -- Backfires
After reading on the forum ....for hours!!! I decided to check my fuel pressure at the rail as it's the only thing I haven't done yet.
After running at idle for a few minutes ....31PSI.
just turning the key to the on positiin on a cold engine resuled in 2PSI. I turned the key off and on 3 times and it got up to 15PSI....Then started engine and slowly rose to 31PSI where it remained.
When I line up the Line with TDC on the timing cover the piston is at its highest point.... then when I turn the crank to line up the V8 Symbol the Piston is just starting to move downward. I have set the Distributor and rotor to line up with the notch in pick-up coil and it seemed to run better when I used the line setting and not the V8 setting. Now still dealing with the low fuel pressure issue and thought I will have to get that corrected before I can go back to setting distributor.
Well I thought I did.
I have removed the bed of the truck and replaced the pump with a New Delphi unit from A Z.
Now I have even lower pressure to the rail at 20 PSI while running and it does not get higher than that..... but it does run with better throttle response but still feel sluggish and backfires. The IAC Hisses all the time too, very loud! I have unplugged the cat to see if this would change that and it has not. I have taken the 02 sensor out and left the hole open and still no change. This is the 2nd IAC that I have put in it to stop the hissing. No luck
So now I have switched gears to find out why I have low voltage at the pump.
At idle I am getting about 8 volts at the pump.... I get 11 when cranking the engine. Still low.
No inline filter on this system so I have blown out the fuel line with air to make sure not blocked.
I have low pressure but seems to be high volume. I think I also had a leaking fuel injector and so I am having them rebuilt and cleaned now.
Relay looks to be working, swapped it out with another a couple of times to make sure,
I follow the electrical from the pump up to the inner fender connection and all seems good then it goes into a massive bundle of wires on the firewall and that's where I get lost.
Any ideas?
If you are getting low voltage at the pump, you are going to have low pressure. Gonna have to trace that wire from the PDC to the pump, see if it is broken, pinched, or corroded somewhere along the line. Either that, or just run a new wire.... (slightly larger than stock wouldn't hurt.)