Hard starting CUCV's

stuinnh · Mar 18, 2011

Just a reminder..... if your cucv is hard to start in both warm and cold temps, hard to start after driving, it is your fuel pressure switch. They crack and leak fuel (or not leak) from age etc. It round plastic with 2 wires and a spring clip holding it in place under the fuel filter in the Stanadyne #80 filter base for MV's only. It is part of the testing port hookup. Not in civy models. $10 fix. When they go bad it will seem like there is a leak in the fuel syster and can blow white smoke from exhaust.
I had replaced everything including having injection pump rebuilt. Even installed check valve in fuel line. Later found out the army had issued advisory on replacing them.
You can get them from Owen's Export.

Warthog · Mar 18, 2011

Thanks. Do you know where to find the advisory?

What was the $10 fix?

Cucvnut · Mar 18, 2011

I changed my base to a new one about a year and a half ago think its bad allready?

MyAngry85 · Mar 18, 2011

I changed my FF assembly two days ago to a brand new one with out a fuel pressure switch. still doesn't want to start real nice.

etech · Sep 20, 2011

my cucv starts hard the time in the morning, its still been in the 70's and 80's in the morning, and have to crank it over a little in the afternoon after work. but if the engine is warm it fires right up no prob. this just started a few days ago. when it fires in the morning there is a little puff of white smoke out the drivers side exhaust more then the pass side. Any help would be greatly appreciated. I was going to order some glow plugs but maybe it is a fuel issue? no evidence of fuel leaking anywhere but it has been getting really good millage this past month or so, which is a little weird, i usually average 14 to 16 mpg, but last couple tanks it has been getting 19 to 22 average with my 39" tires, nothing has changed. but its getting progressively harder to start in the morning... This dose not make any since to me, only thing different at all, is it had been getting cooler, was about 100 in the mornings and the Glow plug light only would be on for a couple sec. now it stays on for about 20 + sec. and its about 70 to 80+ in the mornings. I was thinking about replacing the glow plugs, and the fuel filter, but Im open to any suggestions... I also know that the drivers side head gasket leaks a little water out the back of the head and down the block when hot, but no evidence of water in the cylinders or oil, tell I just saw the white puff of smoke.
I have 6.5 diesel head gaskets for it and arp head studs but have not put them on yet. I got these because I was planning on installing a Banks turbo kit that I have. let me know what you think, when running its just as normal, runs crisp, great throttle response, not any more smoke then normal.

tequilaiam · Sep 20, 2011

To throw in my $0.02:

I had hard starting issues that seemed to relate to temperature. The real culprit was air getting into the fuel system. Cranking a bit then cracking the bleeder on the filter housing got it started.

After replacing all the rubber fuel lines under the hood I found the culprit. It was, naturally, the hardest one to get to: the feed from the filter into the IP. Turns out the clamp on the IP side was a bit loose. That cleared everything right up.

It seemed like a temperature thing but really was only dependent on how long the thing sat after running. It didn't leak either - guessing the IP pulled enough vacuum to seal it when running.

You can actually get a hand under the intake manifold by going from the rear, next to the vacuum pump standing on the left side of the vehicle. I'm 6' tall and needed to stand on a box but was amazed I could reach it after 30 minutes of playing with different socket adapters and long pliers. doh.

chevyCUCV · Sep 21, 2011

tequilaiam said:
To throw in my $0.02:

You can actually get a hand under the intake manifold by going from the rear, next to the vacuum pump standing on the left side of the vehicle. I'm 6' tall and needed to stand on a box but was amazed I could reach it after 30 minutes of playing with different socket adapters and long pliers. doh.

Wow
I never even tried sticking my hand back there

Genius

762luver · Oct 18, 2011

Do you remember what combination of extensions adaters or sockets did the tirck??

Jerchambers · Oct 18, 2011

tequilaiam · Oct 27, 2011

762luver said:
Do you remember what combination of extensions adaters or sockets did the tirck??

None? I had various 1/4 ratchet swivels and u-joints trying to get the hoseclamp on the IP intake. After I dropped one on the engine I was fishing around for it and realized that I could get my hand back there.

But I may have spoke to soon about that fixing the hard-start. It came back, even with an electric boost pump and the mechanical one bypassed. There's certainly air in the lines after it sits a while but I can't figure where it comes from. The tank is usually under vacuum when I have this issue.....so maybe its pulling fuel back into it.

Zero_cool · Oct 27, 2011

Did you replace the ones on the tank and under the cab?
Another place I had a leak was the bleeder valve on the fuel filter housing.

tequilaiam · Oct 27, 2011

the air bleeder or water drain? I noticed the TM drawing shows a seal for the air bleeder which mine doesn't have. I wrapped some teflon tape around the threads for good measure and it seems OK.

The air leak is deifnately under the hood. I used tygon clear fuel tubing for all the replacement lines and the air is isolated to around the filter area. Probably that pressure sensor the OP was talking about.

stuinnh · Nov 1, 2011

tequilaiam said:
None? I had various 1/4 ratchet swivels and u-joints trying to get the hose clamp on the IP intake. After I dropped one on the engine I was fishing around for it and realized that I could get my hand back there.

But I may have spoke to soon about that fixing the hard-start. It came back, even with an electric boost pump and the mechanical one bypassed. There's certainly air in the lines after it sits a while but I can't figure where it comes from. The tank is usually under vacuum when I have this issue.....so maybe its pulling fuel back into it.

If you are still using orig. Stanadyne 80 fuel filter base, the round fuel sensor switch under the filter is causing it. It is located in the filter base. Only MV version has it part of ice system. civy does not have it. $10 part and your hard starting problems go away. I tried check valve in fuel line, electric pump, injector pump rebuild, all the other parts in the Stanadyne 80 filter base until the fuel pressure switch ....... It's all in that fuel pressure switch cracking with age and may or may not leak fuel, but does leak air. Known problem and fix in military.

I believe Owens Export has them. Or, you can replace the whole filter base and solve problem too.

stuinnh · Nov 1, 2011

I would check glow plugs and the resister on firewall. I had replaced my glow plugs first and removed wire from end of resister and moved it to the 12v connection block close by. Last I would check injection pump pressures.

top_prop · Jan 6, 2012

I've got fuel dripping from my water drain line. I've also put in an electric fuel pump and removed the mech pump. If I let the truck sit a couple of days it will fire up, then stall out about two or three times then run like a top.

Any sugestions on where to find a new oring for the water drain? I read in the Hanyes Diesel Tech manual this is a common problem, and there is a new designed O ring for it, but the main diesel shop around here that is a Standadyne authorized rebuild center seems to know nothing about it! They just want to rebuild my IP!

stuinnh · Jan 6, 2012

Replace fuel pressure switch in Stanadyne 80 filter base. Switch is only in military CUCV's. Part of Ice system. Either replace fuel pressure switch, its round and located under square filter. When bad it may or may not be leaking fuel. Also when bad, it will feel and sound like fuel fuel line leaking air. I put check valve in fuel line, replaced fuel pump with electric, replaced fuel heater also located in the fuel filter base and had the injection pump rebuilt by pro.
In morning very hard starting even if temp around 60. after morning first start I was good for most of the day depending how long the truck sat. This was a known problem in military and was replacing them First truck was a 1009, t My 1008 came from the local FD. It was supposed to be used by them for a brush fire truck with water tank etc. The had problems starting it both winter and summer. They replaced the fuel filter to a regular truck fuel filter but still had problems. Their mechanic converted the truck to 12v. When they did this, they did not know to bypass the firewall resister. Replace Fuel sensor switch $10 item.
Stanadyne dealers would not know of this military version of the Stanadyne 80 filter.

top_prop said:
I've got fuel dripping from my water drain line. I've also put in an electric fuel pump and removed the mech pump. If I let the truck sit a couple of days it will fire up, then stall out about two or three times then run like a top.

Any sugestions on where to find a new oring for the water drain? I read in the Hanyes Diesel Tech manual this is a common problem, and there is a new designed O ring for it, but the one of the diesel shop around here that is a Standadyne authorized rebuild center seem to know about it! They just want to rebuild my IP!

tgtaylor64 · Jan 7, 2012

Where can I purchase this switch? Can you provide part number?

top_prop · Jan 7, 2012

Stu in NH... I read all the posts here before I posted... including what you just posted when you quoted my post....

I'm saying the fuel is dripping out of the water drain line, and I believe that the cause is probably the o ring (5 in the diagram below). I've also read it is a common problem and standadyne redesigned the o ring...

you are saying I need to replace the o ring (3) for 15 below because that is what you did?

Even if that is it, where should one get the part? Sorry that I don't know the fuel filter so well and am skeptical that 15 is causing fuel to drip out of my water drain line (24).... seems like I've got different symptoms. But I still need an standadyne fuel filter part source.

stuinnh · Jan 7, 2012

I got mine through Owens Export Owens Export Service Vehicles Parts & Surplus Electronics 818-772-0806

stuinnh · Jan 7, 2012

If you remove filter from base you should be able to see switch and and if it is leaking from there.
Again, this is for hard starting in both cold and warm weather. If leaking is not from pressure switch then you may be right. Of course the easy way to deal with it is replace military filter base with civy one. My 1008 has a cummings filter base in it.

Hard starting CUCV's

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