Need mechanic Dallas area

[swebster]

Could be fuel leaking out of the bowl overnight (time for a carb rebuild) or your mechanical pump is not drawing enough from the tank to crank. I can't remember if the 310's have an aux electric pump on them. I know the longer coaches do which basically act as a "pre-pump" to get fuel pressure up to the mechanical pump.

If you do have an electric boost pump double check the filter between it and the mechanical pump. Also check to see if the electric pump is coming on and pumping fuel (you can remove a line into a bowl and have someone turn the iginition to "ON". Also check the vent on the fuel tank for a blockage.

If you don't have an electric boost pump, make sure there are no leaks in the flex lines or connection. Also check for old rubber fuel line as it can collapse under suction.

You hard starting in the morning could also be related to failing oil control seals on your valves or worn valve guides letting oil down into cylinders overnight. Makes for a hard start, runs rough (puffs of white smoke from the tailpipe) then clears up and runs all day long.

Pull a plug or two in the morning and check for oil. Run the engine, then check it again. If the oil is gone and it starts right up you might have your source.

[guy99]

I can hear the rear (electric) pump come on when I turn the key.

Where is the front pump and how hard to replace?

[noiva]

Originally Posted by guy99

I can hear the rear (electric) pump come on when I turn the key.

Where is the front pump and how hard to replace?

At great risk , I'm going to tell you that on my last 454 Chevy engine it was on the lower right front of the engine. Held on with 2 bolts. Unscrew the fuel line, then the two bolts. The pump has a gasket against the lower block. Fairly simple to do, IF you can get under your MoHo. BE VERY SURE THE ROD THAT IS IN THE BLOCK IS FULLY UP INSIDE WHEN YOU PUT A NEW PUMP ON. Sounds basic, but I actually bent one of those 20 years ago - so badly it couldn't be removed. Anyway, just reverse the process to mount the new pump.

[swebster]

Tim is right on the money about the pump. There is not a lot of access to it in the P30 (from below or through the passenger fender well).

There are three hoses on it, the supply, the feed and the return. In my case, getting the old hoses off took longer than removing the pump due to access contraints. Obviously this would be a good time to replace those hoses.

Getting the pushrod in the right place takes some patience. After I replaced mine I read a post about using some grease to "hold" the rod up in the engine on the cam to make the installation easier.

Before you go too far, check those plugs in the morning. They may tell the tale (lean, rich, oily, perfect, etc).

[guy99]

Well, its not the fuel pump. Unless they fix themselves.

Last night we stayed at Doc's RV Park and Service Center in Las Cruces, NM. Rather than crawl around in the gravel and goat heads hoping they wouldn't notice, I decided to have them replace the fuel pump. When I described the symptoms, they didn't think it was a fuel pump. So I had them come to my site to witness the problem. Pulled off the dog house, took the top off of the air cleaner and sat down in the driver seat. I pushed the accelerator to the floor once and released it. Then I turned the key, almost immediately the engine fired and died. Second try, it started right up and ran normally. The mechanic and I looked at each other and scratched our heads. I said that since it wasn't failing and he didn't think the symptoms sounded like a fuel pump I'd just be on my way.

My wife pointed out that it hadn't been very cold over night (high 40s) unlike the nights when we did have a problem (low 30s). Maybe that has something to do with it.

We headed out and drove the rest of the day without incident. Tonight we're in Gila Bend, AZ. Will see what happens tomorrow morning.

[overlander63]

The choke plate may be sticking open, or partly open. This will cause it to not want to start and stay running first thing in the morning, and it will be worse if it is cold out, as the engine needs the choke almost completely closed to run when cold. fter it is warm, the choke could be hanging partly closed, causing it to run rich, and start to stutter and belch black smoke.
It could be that the choke is stuck in one position, too lean to start when cold, and too rich to run good when hot.
In the morining, before you stsart the engine, push the gas pedal down once, release it, and observe the choke plate position. It should be almost entirely closed, with only a few thousandths of an inch opening. After it starts, the choke plate should open up slightly, if it doesn't, you have a bad choke pull-off. If the choke doesn't move at all , you may have a bad choke thermostat, or the electrical stove is not getting power. If you have a mechanical in stead of electrical unit, you should see a small pipe running from the intake manifold to the rear of the choke thermostat housing. If this is not connected, or is broken, you will also have these problems.

[swebster]

Me thinks Terry is going to win the prize on this one.

[Foiled Again]

Originally Posted by swebster

Me thinks Terry is going to win the prize on this one.

I agree with Terry and SWebster. I had a Honda motorcycle years ago with exactly the same symptoms - and a broken manual choke. Fixed the choke, cured the problem.

Tin Lizzie

[noiva]

Very reluctantly , I,m jumping in with Terry (not reluctant because of Terry, but because of my previous mess-up with my entry concerning the carb floats ). Choke certainly sounds like it. If that plate isn't closing after a good flooring of the accelerator pedal when it's dead cold, you've got your problem. An open choke plate when cold will cause all the symptoms you've mentioned. (I remember guys hovering over their carbs on cold mornings with their hands cupped over the throat to simulate a choke.) Years ago there used to be a manually adjustable spring load on the side of the carb you could dial to make the choke react longer or shorter by rotating the plastic housing. Sort of a "semi-automatic" version of the old pull cables for choke operation. I don't know if you have that on your engine, but it's a round plastic covered cover on the side of the carb, if you do. As Terry has given several possible reasons for the choke to be malfunctioning, there's no need to add much, but I did want to mention the spring load. Waiting to hear the "final" diagnosis .

[route66]

..................When , you get home you might check into converting your old points ignition system over too an MSD Solid state ignition ystem with a 6A module and a MSD billet aluminum distributor . Be the best money you ever spent on that motor home . They build a high quality product and it's very easy to install . good luck on your trip . r66

[noiva]

Originally Posted by route66

..................When , you get home you might check into converting your old points ignition system over too an MSD Solid state ignition ystem with a 6A module and a MSD billet aluminum distributor . Be the best money you ever spent on that motor home . They build a high quality product and it's very easy to install . good luck on your trip . r66

My 89 MoHo has solid state ignition. Were they still using points in '84? Just curious...

[Chaplain Kent]

Originally Posted by guy99

Hello everyone,
We are currently on the homeward leg of our 6000+ mile trip from Northern California to Puerto Peñasco, MX and New Orleans, LA.

.

"

Now that the mechanical wizards have solved your problem and it appears you will be getting home safely can we expect pictures of this amazing trip?
I am quite envious and eager to hear of the travel.
P.S. I am also happy to hear that you are traveling safely with no major mechanical problem.

[guy99]

I'm sitting in the parking lot of a Chevy dealer in San Bernardino awaiting my 7AM appointment wiht the servce department (who may or may not be able to help me before Monday).

We left Gila Bend this morning after having the most difficult time ever getting the Silver Slug started in the morning. Drove 300+ miles passing thru Quartzsite, AZ where we stopped to buy gas (man was that place a zoo) with no problems. When we hit some traffic in this area and had to slow down, the engine began missing and backfiring when I attempted to accelerate hard. Seems to run sort of OK under mild acceleration. Decided not to head for Barstow and stopped here to find assistance. I pulled the fuel filter out of the carb in case that was the problem but that made no difference.

So tonite we'll sleep in the parking lot (they have 30 amp plugs in their parking lot) and see what tomorrow brings.

Life is an adventure.

[87MH]

Originally Posted by guy99

I'm sitting in the parking lot of a Chevy dealer in San Bernardino awaiting my 7AM appointment wiht the servce department (who may or may not be able to help me before Monday)....Life is an adventure.

At this point I would suggest purchasing and installing a fuel pressure kit (see post #6 this thread) - the rear pump may be intermittant - filter/pickup problems, mechanical problems, or electric problems - the oil pressure switches installed on the lower front drivers side of block (safety switches installed so that the rear fuel pump will not run unless the engine is running) have been known to fail.

[noiva]

Originally Posted by guy99

Drove 300+ miles passing thru Quartzsite, AZ where we stopped to buy gas (man was that place a zoo) with no problems. When we hit some traffic in this area and had to slow down, the engine began missing and backfiring when I attempted to accelerate hard. Seems to run sort of OK under mild acceleration.

Hum...Any chance you have trash/sediment/water/bad gas in your fuel tank? Just couldn't help but notice you went 300 miles with no problems, and then as soon as you bought gas the engine began to act up again. Possible stirring up of junk in bottom of tank? Odd that it seems to settle out, but weird things are common with fuel difficulties. Almost sounds like possibly the trash is just bad enough to give you problems, but not enough to completely block the flow. Rear pump, etc. are certainly capable of causing the same symptoms, but that info on filling the tank and THEN having problems kind of stuck out.

[guy99]

My post wasn't clear, I bouht gas in Quartzsite, 200 miles back. I have between 1/2 and 1/3 tank. The station where I bought fuel was very high volumn so I don't think they were selling bad fuel. I've run much lower on fuel and not had any problems.

The filter in the carb looked very clean when I removed it.

The way it acts is sort of like the accelerator pump isn't working or the secondaries are functioning properly. I am confused by the backfiring though.

[noiva]

Originally Posted by guy99

My post wasn't clear, I bouht gas in Quartzsite, 200 miles back. I have between 1/2 and 1/3 tank. The station where I bought fuel was very high volumn so I don't think they were selling bad fuel. I've run much lower on fuel and not had any problems.

The filter in the carb looked very clean when I removed it.

The way it acts is sort of like the accelerator pump isn't working or the secondaries are functioning properly. I am confused by the backfiring though.

Guy,

I wasn't insinuating you got the bad gas during that last fill-up, only that you could have had some trash in your tank all along. If that is stirred into your rear filter when you gas up, some may settle out, but enough could be partially blocking that filter to cause symptoms you're describing. Sure sounds like fuel starvation, so I was trying to go after one of the reasons that can happen. I can't remember, but have you removed the rear filter and shaken it out with the tank side down? Long shot, but if you see any sediment or trash with that procedure, it could point to (or eliminate) trash as a cause. After eliminating that possibility, I'd agree with 87MH that the fuel pump at the rear would be next in line for testing. Don't you just love these bizarre symptoms that no one can quite figure out? Goes with the territory, I guess . Keep us posted. I want to know what to do when my rig does this .

Best.

[guy99]

Well, as I mentioned, I have admitted that I am powerless before this problem and turned it over to my hig.... Oops, local chevy dealer.

I'll keep you all posted. And I'm happy to answer questions for those who enjoy the puzzle aspect of this situation.

[swebster]

Backfiring through the carb or the exhaust? Check to make sure the carb manifold mounting bolts (4 10mm) are tight. I ran into almost the same symptoms and it turned out to be a combination of loose carb bolts (allowing vacuum leak at the carb base - causing backfiring through the exhaust) and a bad frame rail fuel filter.

It drove me crazy with intermittant behavior until I found it.

[guy99]

Steve, the backfiring was through the exhaust.

Dealer looked at the Slug today. Replaced the coil. We took off around 3PM today and made about 140 miles. No further symptoms. We'll see how it starts in the morning.