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Starting issue, fuel pressure?

Calata

NAXJA Forum User
Location
NY
98 4.0. If it sits more than 12+ hours, the first start is 3-4 cranks. I've searched on there for the last couple of days and can't find a firm duplicated problem.

When I put a fuel press gage on the rail, it indicated 0 psi which would seem like a check valve problem. However, once I put the key in and go to crank, the press jumps to 40 psi before the starter even engages. Over the course of a couple of days, I've even tried the 10 second wait, the on/off/on/off/on/crank method, and it's still the same....... 3-4 cranks for initial start.

I've tried releasing the fuel press at the rail back down to 0 ( to try to imitate a bad check valve ) and it starts on the 1-2 crank even after it sits for 4-6 hours with 0 fuel pressure. Since it restart so easily, I don't think the initial hard starts have anything to do with the ECU looking for any signals from a CPS.

My first question is, for those of you with a confirmed bad check valve, how fast does it bleed down? I've left my fuel press gage hooked onto the fuel rail for 1/2 an hour and would still maintain 38+ psi.
 
Mine does the same thing. I usually wait about 10 or so seconds, after turning it to the start position, then crank. Doesn't do it as bad. Thier have been a few threads about this problem, a quick search may turn them up. It takes over night, or about 6 hours unitl I go to start it again, for the problem to happen.
 
Then why the immediate start even after 4-6 hours? Surely the oil press should of decipated by then. Do I have to loose the oil filter and reseat to confirm this?

As for the fuel press, I've already searched and found the p/n for the bmw check valve. I understand that it's under $20, but I'm trying to avoid cutting my fuel line to install the valve if it's not really the problem.
 
My 91 4.0(12K miles chrysler reman.) is that way. If it sits overnight or all day at work it takes an extra revolution or two. If I run out during the day it is fine. I always use a Wix or Napa Gold(Wix) filter because of the construction of the filter. Just my 2 cents though.
 
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