Another intermittent no start issue

BDM

Well-known member
May 23, 2005
333
30
OR
Lots of searching on this one. Mine seems to be difffernt than the usual CPS or fuel pump issues. 99 D1 w/ 107k. This is issue been going on last month or so. Sometimes it starts right up. Other times it just cranks and cranks with no turn over.

Pulling random numbers from the shrader valve. Sometimes I?m getting 34psi other times I?m getting 28. Sometimes only 10psi when in on (position 2). If I let the pump prime in the one position for 3-4s, it usually starts up no problem. However, if I try start it without pausing in the on position, it?ll crank but not turn over. Once I cut it off, I immediately lose pressure in the system. When?s the rover is running, it sits about 28psi. Idles great and drives great as well. Power is fine. I can audibly hear the pump running as well.

I replaced the pump only with a known good used pump. Also replaced the fuel relay with a used part just to x that out. New fuel filter. New battery. Starter and alternator test fine. No change.

Does this sound like a bad fuel regulator? Is there a relay or valve in the sending unit itself that isn?t holding pressure? Thanks for help in advance.
 

BDM

Well-known member
May 23, 2005
333
30
OR
Pump was replaced. Not the whole sending unit just the pump piece inside the housing. It presents both hot and cold so don’t think fuel temp switch. So regulator would be last thing.
 

adriatic04

Well-known member
Mar 22, 2007
2,506
2
cleveland, oh
not saying this is your fault but mine was going through batteries every 2.5 years. I ended up swapping alternator and it ran great right away, previously had same random no starts. New alt fixed it and then a month later, battery wouldnt fully charge, replaced battery and now back to normal. For whatever reason mine is hard on batteries and very picky about having awesome power to start.
 

robertf

Well-known member
Jan 22, 2006
4,781
358
-
Pump should put out and hold 38PSI + at all times.

Its 38 psi (2.5 bar, close enough) - engine vacuum. So only 38 when engine is off or at wide open throttle. 28 is about right for a healthy idling engine, but that will vary with cam and engine wear
 

BDM

Well-known member
May 23, 2005
333
30
OR
Jus wanted to follow up on this. It turned out to be a bad return valve in the fuel pump . Replaced the whole fuel pump unit with a new one from Will and it starts right up every time now, whereas before I had to wait 4-5 seconds for the pump to prime before it would turn over. Thanks to everyone who threw in their 2c!