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Topic: 1990 Grand Villa 6V92 (Read 2035 times) previous topic - next topic

1990 Grand Villa 6V92

We acquired a 1990 Grand Villa with a 6V92 that was parked 3 years ago. I would like to thank Keith Reish for all the help he has given via the phone. I look forward to buying him and Virginia supper. Changed the fuel filter next to the primer pump, cannot get to the secondary fuel filter due to the radiator being in the rear.

Motor spins great thanks to the new batteries. DDEC fuse is not blown. Pressurized the tank and have fuel to the first fuel filter but cannot for the life of the get the primer hard. I can feel fuel moving through the primer. None of the lines show cracks anywhere. Spun the filter loose and repressurized the tank and fuel sprays out with vigor. Tighten the fuel filter and still cannot pressurize the system.

Starts with spray and runs like a top until spray burns off. Any ideas?

Thank you for your help, sharing your knowledge and for this forum

Re: 1990 Grand Villa 6V92

Reply #1 –
You have the 96 inch model with the rear radiator. Our 1993 has the side radiator so getting to the frame mounted hand primer pump is easy. If you do have a primer pump, pull it and check the O rings. Ours were shot but only $0.10/ea at NAPA. Loosen the secondary filter and pump until nothing but diesel comes out, then hand tighten. See my post with photos of the primer. You do need to change the secondary filter. I also put gauges on the primary as well as a gauge on the output of the secondary. Also in a post with photos.

The lift pump is pretty bullet proof so doubt if that is a problem. It may take a bit to fill the entire system with diesel. Our relief valve also had a crack so was letting air in. Also in the photos. Don't use the starter for more that 10 seconds then give it a rest for a couple of minutes.

You will need to be able to change both fuel filters when on the road. I keep a couple of each. Follow instructions on side of filter to hand tighten only. I puncture the bottom with a punch and then drain into a plastic bag or container.

PM with questions.

Pierce

Re: 1990 Grand Villa 6V92

Reply #2 –
Quote from: Pierce & Gaylie Stewart –
You have the 96 inch model with the rear radiator.


Doesn't one with a rear radiator model need to pay particular attention to the fiberglass fan?  I recall a number of folks have had those self-destruct at the most inopportune time.

Fiberglass radiator fan explosion!

Cooling fan 6V92 Detroit rear radiator fiberglass fan

expoding fan parts numbers

6V92 Rear radiator fan replacement

Re: 1990 Grand Villa 6V92

Reply #3 –
Thank you for the primer seal replace and gauge install idea.

As for the fan, it is on my list, once I get it out of the RV park it was left in by the owner that passed away.  The RV Park manager went in for surgery Friday so the owners daughter is running the place temporarily,  and let's just say she is not being understanding at all about the time it is taking to get it running even though we paid the monthly rent.

Re: 1990 Grand Villa 6V92

Reply #4 –
You definitely need to change the second fuel filter. It is on the driver side up high on engine towards rear of coach.

Ken

Re: 1990 Grand Villa 6V92

Reply #5 –
How does one get to the secondary fuel filter? It is a rear radiator. I tried laying across the motor, from the left side, from the right side. Upside down, inside out, I tried in color and black and white, I adjusted the squelch, I contorted my body in ways that I am certain qualifies me to teach automotive yoga.

Re: 1990 Grand Villa 6V92

Reply #6 –
How about from the bottom? Others with rear radiator, ideas, how do you do it?

The rear radiator has some access problems but more than offset by no troublesome hydraulic fan system so will get even better fuel mileage. Horsepower difference between years is just  in the ECU firmware.

Some RVs have gone to a swing out radiator in the back. Fittings are made that swivel.

Pierce

Re: 1990 Grand Villa 6V92

Reply #7 –
Quote from: Pierce & Gaylie Stewart –
The rear radiator has some access problems but more than offset by no troublesome hydraulic fan system so will get even better fuel mileage. Horsepower difference between years is just  in the ECU firmware.
And when you stop after a hot day of driving, you just lift the bed up while the engine's running and let that puppy suck out all the hot air in a matter of a couple minutes!

Re: 1990 Grand Villa 6V92

Reply #8 –
Sorry I didn't address that in my previous post. You get to it from the bottom. It Is up real high. You need to get a filter wrench like this  on Amazon.
GEARWRENCH 1/2" Drive Nylon Strap Oil Filter Wrench - 3149

Ken

Re: 1990 Grand Villa 6V92

Reply #9 –
Update:
Changed out the secondary fuel filter today, fuel system has fuel in both filters and lines using the primer pump I can feel pressure building but doesn't get hard.

Lost power to the starter. Which now I am wondering if the fuel shut off solenoids are opening. Going to have to chase down electrical gremlins. Was turning over great has a low coolant code. Did a reset and pulled the battery cables off as well and when we put them back on no power to the starter. Have power to the solenoid, and out of the solenoid but not to the one on the starter solenoid. All fuses are good including DDEC fuse in panel

Re: 1990 Grand Villa 6V92

Reply #10 –
Quote from: BrettandJana –
Update:
Changed out the secondary fuel filter today, fuel system has fuel in both filters and lines using the primer pump I can feel pressure building but doesn't get hard.
I have been following this thread, but haven't commented because I know nothing about the 6V92.

Having said that, from what you say above, it appears that you have fuel flowing from the tank, through both filters, and through the primer pump.  But you still can't build pressure at the injection pump inlet port.

On my Cummins engine, in the exact same scenario, the only item remaining in the fuel system that would prevent building pressure at the injection pump would be the "overflow valve".  This is a spring loaded pressure relief valve that is installed in the fuel return line where it exits the injection pump.  This valve regulates fuel pressure in the "low pressure" section of fuel line between the lift pump and the injection pump.  On my engine, that pressure should normally run about 20psi at idle.  If it was to get stuck open, say by some trash in the valve or a broken spring, then on my engine the fuel pressure at the injection pump inlet would never build, no matter how much I pumped on the primer hand pump.

Fuel System Science Project

I don't know if the 6V92 fuel system works like the Cummins.  I'm just mentioning this valve because Pierce said (in Reply #1): "Our relief valve also had a crack so was letting air in".  I assume from this that the 6V92 has a similar valve somewhere in the fuel delivery system.  You didn't say anything about checking this component on your engine, so I thought it might be worth looking at.

Re: 1990 Grand Villa 6V92

Reply #11 –
Where are you located?
There may be a member close by that can offer assistance.

Re: 1990 Grand Villa 6V92

Reply #12 –
Fuel System Science Project
I don't know if the 6V92 fuel system works like the Cummins.  I'm just mentioning this valve because Pierce said (in Reply #1): "Our relief valve also had a crack so was letting air in".  I assume from this that the 6V92 has a similar valve somewhere in the fuel delivery system.  You didn't say anything about checking this component on your engine, so I thought it might be worth looking at.
[/quote]
Chuck,
No, the Detroit 2 cycle has no injection pump like your Cummins but rather an extra lobe for each cylinder on the two camshafts, which in turn, operate a the unit injector located at each cylinder. CAT also has made some engines like this. So, you need to check the outlet for the secondary fuel filter for fuel discharge. From the secondary filter, fuel flows up to a fitting that directs it to the cylinder heads where all fuel flows through internal cylinder head passages to small pipes that connect to each unit injector. That's why I put a gauge on the outlet of the secondary. I can check it while using the hand pump or check the pressure while the engine is running as seen in the photo. The valve that restricts fuel from running freely back to the tank is shown in my hand primer pump photo (the gold one) and is spring loaded so the injection system always keeps fuel in the system. It's easy to see close to the hand primer pump.

On the engine side of your Bosch P pump on your mechanical Cummins, you have a small valve with a spring and ball inside. This valve keeps the required pressure inside the internal P pump reservoir and lets fuel return to the tank when the lift pump pressure goes over the valve specificaation. Never hurts to replace this valve after 100K as the little ball develops microscopic surface passages so drops pressure in the pump thus reducing engine power at full throttle and possibly shortening pump life in extreme cases.

Low coolant level may also keep the ECU from triggering the electronic injectors. While Detroit 6V-92TA diesels are made with both mechanical and electronic fuel systems, all 2 cycle Foretravels have the electronic engine. It was the first OTR diesel to be made with electronic injection.

Tom Hall installed an electric fuel pump in his MCI bus with a 8V Detroit that make it super easy to prime the filters and evacuate any air in the system. If an electric Bosch fuel injection pump is installed, it's pressure will exceed that of the return valve so allowing the diesel to push all the air out of the system and back to the fuel tank. These pumps are cheap and a five minute removal at a Pick N Pull yard. Located back close to the fuel tank in Euro cars.

Check coolant level (instant check) and then fuel discharge at the secondary filter first. If a Detroit 2 cycle runs out of fuel, it can take a while to get the air out of the system. There are no fuel lines on the outside of the engine to crack and bleed but rather, internal cylinder head passages to clear of air. A leaking injector may drop the system pressure and allow air in the system over a period of time. Since our Detroits don't have a heated intake screen, warm weather really helps start a reluctant engine.

Pierce



Re: 1990 Grand Villa 6V92

Reply #13 –
Maybe you can crack the fuel inlet line at the engine pump  and try to  prime. ?

Re: 1990 Grand Villa 6V92

Reply #14 –
I am sorry I didn't update. We could never get it started, changed both fuel filters, primed the system, pressurized the tank, she would start with spray, DDec fuse change, no codes.

This coach was a freebe at an RV park that they were stuck with because the owner died. We paid rent on it a couple months worked on it every weekend. A good buddy of mine drove in from Nac. And we tried all the Foretravel Tricks he knew, no luck at all.  We ended up letting it go, it was going to be $2000 to tow it the 81 miles that's with our Good Sam Platinum Membership or with CoachNet. We were pretty bummed about it.

Re: 1990 Grand Villa 6V92

Reply #15 –
Thanx for wrapping up the story.  ^.^d  Always kinda irritating when a poster leaves us "hanging" without a final update...successful or not.

Re: 1990 Grand Villa 6V92

Reply #16 –
For future reference,next time "let it go" to the forum members.

Re: 1990 Grand Villa 6V92

Reply #17 –
Once you know the little diesel secrets, it's pretty easy to get any of them started. Otherwise you just pull your hair out. Anything that has been sitting and does not start can usually be traced to the fuel system and less than new batteries.

Members want to know how it was resolved. Where is the coach now? Some members may be interested in it.

What kind of condition was it in? Interior? Etc.

Pierce

Re: 1990 Grand Villa 6V92

Reply #18 –
An update on that 1990. We met the gentleman that bought it. He had it towed to a shop to be repaired. $7200 later, the DDEC2 computer was toast. They had to get a new one and have it programmed. He also had every fluid changed, new front wheel bearings installed and the generator tuned up and serviced.

Re: 1990 Grand Villa 6V92

Reply #19 –
John 44 I wasn't sure what you meant by

" for future reference " let it go" to a forum member"