Fuel Pressure Switch and Hard Starting CUCV

[stuinnh]

Glad I could help.

 

[owensexport]

Thanks!!

Steve
www.militaryjeep.com

Thank you for the excellent advise. THis is the best $26 I have ever spent. For the first time in three years the truck started this morning and kept running--just tapped the fuel, waited for the glow plugs to cycle, cranked and it started and ran. Temperature was about 25 degrees. This is a first for me and this truck. Also, the part I got from Owen's (a great place for parts and an interesting guy to talk to) was a type 3. The instructions say you need a special tool available from the manufacturer. I believe the tool is to help prevent damage to the part, but I used my thumbs after lubricating the O-ring, and it seemed to work fine, and the new-style retaining clip that is attched to the part was easy to get in place with a screw driver. Thanks again--this is a great place to start for anyone who is having problems with air getting into the fuel system on a 1008.

 

[owensexport]

 

[Warthog]

Intestesting side note. The package says SWITCH, PRESSURE but the tech manuals and wiring diagrams call it a vacuum switch.

 

[mikev]

I had long "cold" cranking times on my '86 M1009 and finally switched out my "old" style fuel filter base (w/ the pressure sensor) with one without the sensor ("newer" style ?) and now my CUCV starts after a couple of revolutions like it did when I bought it in 2000.

It helped to "relearn" the proper starting procedure too (I wasn't pushing the pedal down to help set the cold idle speed solenoid and holding the pedal partially down during "cold" cranking - definitely helps with cold startup and less smoke...).

Thanks Stu...!!!

 

[lindyp38]

View attachment 412610

thanks.....it starts up much better than before........thank you....

 

[Small Prepper]

Well - just got finished installing the vacuum/ pressure switch. WOW hat a differance. Starts right up now. My 1009 was a beast starting up when it was below 50 degrees. It killed my batteries and I replaced them. I started with glow plugs didn't help. Change filter again still didn't help. After reading this thread and replaced this switch. All I can say THANKS STUINNH for posting this.

Again Thanks
Roy

 

[lolercaust]

Just ordered mine, "Big Ugly" is an odd ball at starting and does not start easy when it's hot. ill let you all know what happens.

 

[MarcusOReallyus]

???

Why are you guys spending money on a pressure switch that isn't used? Did you not read the whole thread? The pressure switch isn't used, and all it takes to fix the problem is to remove it and plug the hole with a bolt. Done.


Better yet, replace the original filter with a modern spin-on, and no pressure switch.

Done.

Oh, well, it's your money.

 

[2deuce]

I wish my hard starting fix was this simple. I replaced the filter base with one that didn't have the hole for the switch and the problem was not cured. If I park the truck with the nose up, even with only a slight incline, it seems like fuel must be pumped all the way from the tank. Sometimes a full minute of cranking. If I park with the front of the truck down, it will start with about 5 sec of cranking. I have a leak somewhere else, but it has not shown me a fuel leak, only a drain back leak. Truck runs smooth after a minute or two and all the air gets out of the fuel system.

 

[MarcusOReallyus]

That's what electric pumps are for, to turn air leaks into fuel leaks so you can find them!

 

[TheEndIsNear]

2deuce, did you ever figure out your problem? I'm having a real similar issue with my M1008 and I've read all of the post and threads and now stuck. I've replaced in this order: Glow Plugs, Fuel Filter Housing and Filter, Fuel Pump (same mechanical), rubber lines, after all of those it ran OK for a while then seemed to die. If I didn't park it on an incline with the front down, it would never start or drive. I did finally get it to my neighbors house and it stalled there, had to drive it home in reverse as I'm up the hill from him.

Just this week I got a new Pressure Switch put in and then realized that I had a kink in the rubber line right off of the Pump...I'm an idiot, can't believe I didn't check that 1st...Cut that short, got rid of the kink and the truck ran better than ever. Strong, smooth, shifted down like it was supposed to when on the throttle, plenty of power!! Drove it to work yesterday, about 10 miles - perfect. Now today, drove about 5 miles and barely made it home. Full tank of Diesel so I can't imagine what happened between yesterday and today.

Before I got the Pressure Switch, I thought about dropping the tank...Please let me know if you ever resolved your issue because at this point, I think I have the same.

 

[buick]

Best way to go. get a 1/4 " tap, tap it ,place a 1/4 screw in snug and after you get the lines bled, just bump the key. WHY SPEND MONEY. Thanks kentuckycucv. Starts better than before. 1985 M1009 103.--- miles.

 

[azex]

I wish my hard starting fix was this simple. I replaced the filter base with one that didn't have the hole for the switch and the problem was not cured. If I park the truck with the nose up, even with only a slight incline, it seems like fuel must be pumped all the way from the tank. Sometimes a full minute of cranking. If I park with the front of the truck down, it will start with about 5 sec of cranking. I have a leak somewhere else, but it has not shown me a fuel leak, only a drain back leak. Truck runs smooth after a minute or two and all the air gets out of the fuel system.

I just started a thread looking for the part which is purported to fix this problem. It's a pressure regulator, that is right "at the top front" of the IP. Here's the link.

I'm just too cheap to spend 55 bucks on the **** thing and trying to find one locally in AZ.

http://www.steelsoldiers.com/showth...re-regulator-check-valve-Pt-number-and-source




http://www.ssdieselsupply.com/p190_fuel_pressure_regulatorcheck_valve.html

I am told by diesel gurus that the IP "timing" is regulated by the backpressure of this valve and if it doesn't work or is worn out (what ISN'T on these trucks?) then you'll get weird surges and stalls at odd times or on inclines or declines. The truck just runs intermittently or with varying degrees of power. That's EXACTLY what mine is doing.

It's also a return line check valve.
D.

 

[Warthog]

The check valve you are asking about is totally different than the Pressure Switch that this thread is talking about.

 

[azex]

His issue, AS QUOTED, is relevant to my reply, Napoleon.



D.

 

[mrwalleyz]

I've been dealing with this, chose the cheaper route. I however used a self tapping screw with a collar and fitted a correctly sized o-ring. I assume being totally dry now also means no air getting in. Worked great for me. Now i'm starting to toubleshoot the GP module/relay/switch issue. But thanks to you guys for pointing out the tm's, and the importance of research time prior to questions. I have learned more that way.
Great site-Great people.

 

[wjford9]

Problem solved! Figured I'd try the free easy fix since switch is not needed. Hole was perfect for a #10 screw and tap

 

[MAZ537]

I also have a leaking PS and I wonder if it is safe to have this hole TIG welded instead?

 

[Tinstar]

I also have a leaking PS and I wonder if it is safe to have this hole TIG welded instead?

It will take you longer to setup the welder (if it's possible to weld) than to just plug it forever as already mentioned.