What's your startup ritual?

[Kelpiesgmc]

I'm wondering how you all start your coaches. I give mine one full press on the gas pedal and crank it. Sometimes it starts right up. Sometimes it cranks a while and I have to give it a little break before trying again. Not sure why. Doesn't seem to be correlated with how long it's been off. Sometimes it sits for days and starts right up. Sometimes it's hot and takes a while, and pretty much every other combination.

I see that the carb will be in "hot mode" until you give the throttle a full "stomp". I've heard of people saying you should do 3 pumps on the pedal before starting. Not sure if there is any truth to that.

I have a new 455, new carb, new fuel pump (with an electric pump on AUX). Runs great once started. Though I do have my idle set maybe a tad low. I set the idle with a tach and timing light attached, but in actual use it rests a bit lower than it did when I was calibrating.

 

[RF_Burns]

I just turn the key, don't touch the gas pedal, and it always starts with about 1-2 seconds of cranking. Doesn't matter whether its been sitting for a few months over winter, or if I just refueled and back on the road.

One of the big advantages of Fuel Injection.

 

[RvRev2]

Carb engine here. Three pushes on pedal, then crank. If it hasn't been sitting long, it starts right up. If it has been sitting for awhile, I'll need to pump the pedal a little while cranking.

 

[Tom Katzenberger]

The cranking is good because the whole time you are cranking , you're moving oil through the system and lubricating prior to startup.

My recent research has found that carburetors get more horsepower than fuel injection. Reason being is that the venturi effect in a carburetor causes the fuel to cool considerably , allowing more fuel into the cylinders , as opposed to fuel injection. Both have pros and cons, but I would never disregard the carburetor even though I like the simplicity of the fuel injection system. It comes down to Atomization, versus Vaporization and the cooling effect of the fuel going through a venturi.

Good stuff , and everyone have a wonderful day.

Tom K.

 

[Luke]

Pump it once, then hold the pedal at 1/3 and it will start up quick, works on carburators. My brother taught me that on our '79 Plymouth. On EFI I turn the key to On and wait a few seconds for the friend fuel pump to pressurize, then start it. If it's sat awhile I'll disconnect the ignition coil and crank it for a few seconds pause a bit and do it again a little longer, do it a few times to get the oil circulating before actually starting.

 

[billvv]

1-2 seconds here with the GM throttle body EFI/EBL system. Even at altitude.

 

[mech0001]

With my hybrid FiTech (first version), I cycle the key a time or two, giving each a couple of seconds. The system injects a quick burst of fuel into all ports after the system boots up. The same operation is usually necessary after a hot engine stall. Pretty much the same as pumping your quadraject to spray in some fuel. Lots of fuel injection systems benefit from key cycling, though most do not directly inject fuel until the starter is engaged.

 

[RF_Burns]

The cranking is good because the whole time you are cranking , you're moving oil through the system and lubricating prior to startup.

My recent research has found that carburetors get more horsepower than fuel injection. Reason being is that the venturi effect in a carburetor causes the fuel to cool considerably , allowing more fuel into the cylinders , as opposed to fuel injection. Both have pros and cons, but I would never disregard the carburetor even though I like the simplicity of the fuel injection system. It comes down to Atomization, versus Vaporization and the cooling effect of the fuel going through a venturi.

Good stuff , and everyone have a wonderful day.

Tom K.

EFI cuts the fuel OFF when you turn the key OFF so the cylinders don't continue to pull in fuel that will not be burnt. That unburned fuel in the cylinders will wash down the oil on the cylinder walls leading to metal to metal contact on the next startup. One of the reasons a modern engine lasts longer before a rebuild is required... except recently they have pretty much engineered the engines to just make it through the warranty period.

 

[Tom Katzenberger]

Metal to metal contact either before the start or after the shutdown are the leading causes of shortened engine life.

One of the main reasons tractor trailers get a million miles out of their engines is because they start and shut down much less than typical gasoline engines. When I worked my way through college at UPS they were getting a million miles on the Ford 300 inline six's. No timing chain and 7 main bearing on the crank was another reason why the 300 C.I.D. Ford what's so durable.

 

[Keith V]

...

My recent research has found that carburetors get more horsepower than fuel injection.

...

This doesn't make sense. maybe in multipoint or direct injection, but the TBI is basically a carb

 

[Tom Katzenberger]

Keith,

Not my work.I cheated and copied off the computer.

Carburetors deliver fuel at significantly lower pressures than fuel injection, creating a more pronounced pressure drop as the fuel expands through the venturi. This rapid expansion and the subsequent vaporization (evaporation) of the liquid fuel cause an endothermic (heat-absorbing) chemical state change, which heavily cools the incoming air-fuel mixture.By contrast, modern fuel injectors operate under much higher pressures and are typically mounted directly into a hot engine block or cylinder head, absorbing more radiant engine heat before the fuel ever atomizes.

You take care and have a wonderful evening.

By the way , after five years , i'm still in love with my micro level.

Take care,
Tom K

 

[Tom Katzenberger]

Keith,

Reviewing your question, I tried to think about it and I think that the injectors stop immediately and a 100%. , but perhaps the carburetor is still pulling idle fuel through the ventures , as long as the pistons are sucking air.

Some more to think about.

Take care,
Tom K.

 

[Carl Stouffer]

It depends a lot on the outside temperature. Sometimes, in the Summer, one pump on the gas pedal to set the choke and squirt a little gas in via the accelerator pump, is all it takes. Other times, when the weather is cooler, it takes a couple of pumps to get a little extra gas in there.

 

[Richard RV]

So it looks like I'm the only one whose ritual includes sacrificing a goat...

 

[dsmithy]

I posted my ritual on one of Tom's other threads.
On our carbureted (and high mileage) '73 I crank the engine till I have good oil pressure before setting the choke and starting the engine. With our robust starters and an engine that turns over relatively easily it has not resulted in extra wear and tear on the starter and the engine seems happy. Thirty years with this coach and no engine problems with this approach. It's also important to note that no goats are harmed in the starting of my coach.

 

[boybach]

First thing, turn on master battery switch. One pump, crank and she fires right up, winter or summer. A bit thumpy at idle at first but smooths out once warm. 403 w/42,000 miles, carb. Relatively new starter motor and battery.

 

[Kendra]

1) Hit both knees on the NGMC-2010 'Big Mac Dash' that eliminates driver legroom. The kit's gauge quality resembles Barbie's GMC Motorhome. Decals would be more reliable.

2) Pump the Rochester QuadraToilet one time too many. Starts within 2 seconds, runs 5 seconds, then stalls. Clockwork.

3) Remember slowly open throttle half way and don't stall it next time or some random guy will walk up and offer expert advice although they haven't driven a carburetor in decades and can't explain it without AI.

4) Third try's a charm. Starts after 5 seconds of cranking, stays running if I feather the throttle for the first successful minute. Now that it's behaving I sip coffee and look forward to immediate starts the rest of the day.

5) Now it's tomorrow. Time to repeat this ritual.

Always gets me there. No plans for fuel injection.

 

[Tybalt39]

1) Hit both knees on the NGMC-2010 'Big Mac Dash' that eliminates driver legroom. The kit's gauge quality resembles Barbie's GMC Motorhome. Decals would be more reliable.

At first I really wanted that monster dashboard, if only for the additional space for whatever I might install in the future. But then I thought about the legroom (I'm over 6ft and not getting any more limber).... The Supreme II should be enough extra space for me.

I'm not contributing to the startup thread as I went EFI; it just starts (touch wood, please no red flags...).

 

[Kendra]

I'm 5'7" (170cm), and I have to do creative legwork to get around the aftermarket dash with the factory seat all the way back.

 

[Kelpiesgmc]

I really value simplicity, so I'm staying away from fuel injection systems for the 455. That said, I really can't stand the looks of concern you get when your 53 year old Motorhome cranks for more than 10 seconds. it's even worse when the damn v-belts squeal. I would love to do a serp-belt setup one day