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fuel pressure problem

705 views 9 replies 3 participants last post by  Cc.cornelius 
#1 ·
I have a 01 2500 5.9 5spd with 312k miles and no upgrade mods. Originally thought my issue was a apps. i put a new timbo on it and my problem is still there. It surges/bucks around 1800rpms and running 65mph or so. it has a intank lift pump. i tested fuel pressure i get 10psi when i bump the key and the pump runs for 20 sec. as soon as i start the truck i have 0 psi. also my wait to start light occassionaly does not come on unless i flick the relays. could this be a bad lift pump? bad ecm? how would i test to figure out my issue without replacing a ton of $$ parts. also vp44 shows no failing symptoms besides the surge i get at high way speeds.
 
#3 ·
Have you checked for codes?
 
#4 ·
Yes. Originally I was getting a po122 and a po121 which is why I changed the apps. Since then I am getting no codes using a obbii scanner.how this started is a went down a very rough country road, as soon as I got on the high it did a very hard surge..and then the rodeo was on. I can drive all through town with no issue. As soon as I get on the highway it start bucking again.I know it's got to be a fuel issue. Just don't know if my lift pump is trashed or ecm isn't telling it to run while truck is running. Pump does come on when I do the key bump
 
#5 ·
If you have zero fuel pressure, First I would check the plug on the lift pump and make sure its getting power. If it is then lift pump is bad. If not then it could be the computer. But either way I wouldn't run it let alone run it without fuel pressure. Look at an aftermarket pump with a draw straw or sump.
 
#6 ·
Did not normally run cruise. I've only had the truck around 3 months with nothing but issues. I can say it makes no difference using cruise or foot it still surges
 
#7 ·
Is there a way to test the in tank for power? Can I probe it with a volt meter? If so should be 12v while running? I've read on the forum that the ecm pulses it while priming. Does it have continous voltage while motor is running
 
#8 ·
you should be able to get a solid 20-25 secs of voltage. im unsure of what voltage it should be but im sure you should be able to find it on google somewhere.
 
#9 ·
I will eventually do like a raptor 100 with draw straw kit.. But right now I just need to get this thing back on the road.can't really afford to do ecm and lift pump all at once.. Or the truck will be down for a few months
 
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