Engine/Transmission (1994 - 1998) Tough Starting After Installing New Overflow Valve

[Sasquatch]

My '97 was running okay, but not getting the mileage it used to and not delivering the same power, boost, etc. I was also aware of the much-publicized "ticking" that everyone seems to mention when describing fuel-related problems.



So, I replaced the overflow valve with the "$35. 00 (plus shipping) special, and I noticed an immediate improvement. The ticking was gone, completely. I also replaced the fuel filter, cleaned the AFE air filter, and flushed the fuel heater screen that same afternoon.



Next morning, the truck didn't start easily. Had to pump the pedal and turn it over a couple of times, and it coughed and sputtered starting up. I also thought I smelled raw fuel, but didn't see any signs of a noticeable leak when I looked under the hood. Driving the truck during the remainder of the day, it started up whenever I got in it, and there was no repeat of the problem...



But, next morning after sitting all night, the same exact thing.



My concern is that maybe I didn't tighten the overflow valve enough and air is somehow getting into the system. The old valve was pretty loose when I changed it out, requiring very little effort to remove, so I didn't over-tighten it when I put the new one in.



Once I've driven the truck during the day, it starts every time no-problem. It seems to be only the first start of the morning when there's a problem, and even then it's not a huge effort to start. It just doesn't start as easily as it used to before I swapped out the overflow. It'll sputter, cough for a second, then fire up. It's kind of like when you change your fuel filter, and you haven't gotten a perfect, 100% prime; the truck starts, but reluctantly.



This morning, same story, and I thought i could smell fuel in the cab, but I can't see it when I look around under the hood with a flashlight and check the most likely trouble spots. It looks a little like there's a damp spot right under the overflow valve, itself, but it's not really "wet," and could just be my imagination. I tightened the nut very slightly more, because I'm afraid to deform those washers and tear them up.



The truck always started instantly before changing out the overflow, so I doubt that i've suddenly developed another unrelated problem. I'm wondering if I could've gotten a faulty valve, or if there's some trick to installing it that I don't know about. I just unscrewed the old one, put the new washers on either side of the valve, and screwed the new one back in...



Any thoughts or advice would be appreciated.

 

[Will24]

My guess would be that it's loose... A slight air leak will slowly lose prime, but probably not show it's head while the truck is running. A 12v lift pump will MOVE some fuel!



Also, have you ever replaced the fuel lines? (suction and return)



-Will

 

[Sasquatch]

Will,



I've never replaced the fuel lines, but I've checked the fuel return line and done a visual inspection on the rest of the lines pretty frequently.



That's a good thought, but I suspect it's related to the overflow valve installation, itself, rather than a leak in the fuel line someplace. Could be, though. You have to move the section (metal?) of the line that's connected to the overflow valve, so I guess it's possible that an old section was somehow weakened in the process and began to leak air.



My concern is getting on that overflow valve nut and cranking the pucky out of it I might deform one of (or both) washers to the point where they are ruined. As I mentioned, earlier, the original valve was pretty loose when I went to take it off. I used an adjustable (crescent) wrench on it, and it was just a little more than "finger tight," when I broke it loose. It was so loose, I suspected that it might have somehow contributed to the problems in less power/mileage I was experiencing.



The new one has been torqued significantly tighter, now, than the one it replaced; that much is for sure.



It just seems too coincidental that I'd have no starting problems at all, decide to replace the overflow valve, and all of a sudden i've got a hard-starting problem that's linked to a faulty fuel line someplace else on the truck. I guess it's theoretically possible, but it seems unlikely...



Thanks for your reply.

 

[KYOUNG]

tough starting

I would check your fuel heater again and make sure you are not loosing prime there. There is a little green seal that goes around the fuelheater plugin that can be easily missed...



I had problems with mine and just removed the whole heating element and put it back together... no more leaks!!

 

[CarlJensen]

9 times out of 10 you will not be able to "see" a bad fuel line! They get checkered (cracked) from the inside out and it only takes a very small air leak, with no drip, to lose prime overnight or faster. Fuel heater leak is the same deal, you may not see any drip or fuel at all.

 

[Sasquatch]

I'd like to replace the fuel lines. The truck has 150,000 miles on it, and it just makes good maintenance sense.



Does anybody make a kit for this operation, or would this be one of those rare occasions when it'd make sense to have a good dealer (hack, spit, ptui!) do the job?



Also, I have a PrimeLoc filter relocation kit that has the 1/4" npt fittings so it'd be easy, I guess, to install an under-the-hood fuel pressure gauge. Anybody else done this, and, if so, what type/manufacture do your recommend, and where can the gauge be sourced?



Thanks

 

[Joe G.]

Sasquatch,



Look here: http://www.fostertruck.com/dodge/default.htm

 

[Sasquatch]

Thanks, Joe:



I bought and installed Larry's starter rebuild kit a couple of years ago.

 

[K5IP]

I also vote for the fuel heater filter area. A prime source for a loss of prime.

Even if you need new fuel lines, it is unlikley that they failed just at this time.

Fix one thing at a time or you will have so many variables you won't know where to start.

Rog

 

[JohnG]

Fuel guage

I'm finally getting to do some bombing tomorrow. (a #10 plate and timing up a bit). Also Finally getting guages hooked up after mounting a month ago. I bought Hewitt guages because after reading TDR a lot, I found one fellow who said the backlighting w/ 2 green booties on the bulbs, matched the stock panel brightness and the look the best. HOWEVER, they, like most other manufacturers only had like either 30psi or 100psi guage, so I talked them into making a 50 psi fuel pres guage !! Basically a 50 psi man. pres guage w/ a new face. . and it looks great. (The reason for the 50 psi, is that I heard that the P7100 will push above 30 psi at times when letting off the accel. , and I hate to pin guages) , (ie: w/ the 30 psi guage). . I will see them lit up tomorrow for the first time. Oo. JohnG

 

[Joe G.]

Good choice. I peg my 40 PSI guage once in a while.