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Topic: Dead On Side Of Road: Fuel Starved/Vapor Lock? (Read 2296 times) previous topic - next topic

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #50 –
I would not use a Holley or a Quadrajet, Go with the Edelbrock Performer, just like a Quadrajet, but works much better.
A 650cfm instead of the larger 750cfm would give you more low end torque and much better mileage.
You won't be revving that engine to 6-7000 rpm to ever use the extra airflow the large carb has.
1995 U320C SE 40'
Jeep 4x4 Commander - Limited - Hemi
"The Pack"  Yogi and Diesel our Airedales -  Charlie our Boxer/Akita mix. Gone but NEVER forgotten Jake our yellow Lab.
NRA Law Enforcement Firearms instructor - Handgun/shotgun
Regional Firearms instructor for national Armored Transp. Co.

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #51 –
Check your spark plug wire order. If one of the wires got crossed during all the maintenance, this can result in your symptoms: overheating, lack of power, stalling, and flames shooting out of the carb while backfiring, etc...

Ask me how I know this. Had a 454 once upon a time.

Hopefully the jet(s) didn't get clogged during the maintenance.

1997 U270 34FT Build 5140 Cummins 8.3 Allison 3060R
Solar 1920Watts, 14KWH lithium. Orion BMS.

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #52 –
Ignition timing needs to be checked. Timing chain could have jumped a tooth which will retard the timing causing a low power condition. Usually they jump when you shut down the engine. But can jump when running under the right conditions. How many mikes on engine ?
91 GV U300 Unihome 40' Build 3811
6V92TA Detroit

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #53 –
Quick update on this:

We drove 55 miles today. No issues. Temp stayed normal. I have more power than I did with the old fuel pump. Seems to need less throttle to hold highways speeds. Keeps finding myself speeding... which is a problem I've never had before.

O rly things I changed since the fuel pump and dieing on the side of the road... rerouted fuel line to not be directly over the engine. And wired the auxilarly electric radiator fans to a dashboard switch instead of the probe thermometer switch. I ran them for the whole drive.

I'm not sure if I've solved my issue... I feel like those two things were not difficult enough... I didn't injure myself doing them... and there was no cussing involved... so my problem can't possibly be fixed. Lol. I hate intermittent issues.

When we stop for a longer period of time next week, I'll run all the tests I haven't completed that you all have suggested and report back.
Husband & Wife Team. 3 Kids. 8 yo boy, 4 yo girl, 19 mth girl. Mostly Finished Renovating 1986 Grand Villa 3300 GVF SBI for a multi year trip around the country with the kids.

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #54 –
The Radiator fans if not connected correctly might have been drawing to many amps and causing issues with the power supply? Still guessing on this one but if its fixed for now.. I will hope you are past the issue.. ^.^d  Good Job!!

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #57 –
Thanks @jcus! I actually already had that pdf. It's why I replaced the fuel pump in the first place. But I'm glad to see I'm not alone in thinking that was the issue.
Husband & Wife Team. 3 Kids. 8 yo boy, 4 yo girl, 19 mth girl. Mostly Finished Renovating 1986 Grand Villa 3300 GVF SBI for a multi year trip around the country with the kids.

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #58 –
Chilton's ^^^ recommends an electric pump to feed the mechanical one in certain instances.

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #59 –
UPDATE: So, I was able to drive the coach from Carlsbad NM to San Antonia TX. No longer had any problems with it dying or being fuel starved.

I did have my starter solenoid go out (simple napa replacement) and I have one of my spark plug wires that keeps getting burned up and then causing mis/back firing. I replaced that and wrapped it with spark plug wiring heat shielding. Hope that keeps that from happening again.

I'm hoping that's the end of my issues... though i'm still very surprised that I was able to fix the vapor lock issue with the fuel pump/line rerouting/and putting my aux fans on a switch.

But the coach is running better than ever.
Husband & Wife Team. 3 Kids. 8 yo boy, 4 yo girl, 19 mth girl. Mostly Finished Renovating 1986 Grand Villa 3300 GVF SBI for a multi year trip around the country with the kids.

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #60 –
Quote from: AKATheAlchemist –
I'm hoping that's the end of my issues... though i'm still very surprised that I was able to fix the vapor lock issue with the fuel pump/line rerouting/and putting my aux fans on a switch.
Congrats!  Don't be surprised - sometimes Karma cuts you a break.  Enjoy the "easy" win...cuz they aren't all like that.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #61 –
Thanks Chuck!
Husband & Wife Team. 3 Kids. 8 yo boy, 4 yo girl, 19 mth girl. Mostly Finished Renovating 1986 Grand Villa 3300 GVF SBI for a multi year trip around the country with the kids.

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #62 –
Glad you got your coach to go Alchemist without dying.  I had an 89 Georgie Boy once with a ford gas engine.  The engine sometimes would just stop for no apparent reason.  I would be checking for the cause and after awhile it would start and run fine, until the next episode which might be a day, week, month later.  Changed fuel pumps, insulated fuel lines, and finally figured it was vapor lock, but could not find the cause, because it would happen sometimes when it wasn't that hot and on some hot days would run fine.  The air intake to the carburetor was routed to the right front side of the engine radiator where it would normally get fresh air,  but under the right condition hot air off the radiator would recirculate into the intake and heat up the carb enough to cause vapor lock.  I found this out by chance when I installed a longer air intake farther away from the radiator.  Used a piece of metal clothes dryer exhaust hose.  Never had a problem after that.  There was about a 4" gap above the radiator and body of the RV that would let the hot air off the back side of the radiator recirculate and be pulled into the carb air intake.  I think the direction the wind was blowing and speed of the vehicle may have had something to do with the problem.
Jerry Whiteaker former owner 96 U270  36' #4831 Austin,TX-Owner Mods LCD TV w/front cabinet rebuild - LCD TV bedroom - Dual Central AC, either can cool coach w 30 amp - Skylights at roof AC openings - Drop ceiling for ducting of AC - Shower skylight white gelcoat/wood/epoxy frame - Air Springs/Shocks replaced - 2014 CRV - 8K Home Solar - Chevy Volt
 

Re: Dead On Side Of Road: Fuel Starved/Vapor Lock?

Reply #63 –
Regarding your gas starvation problem, I may have missed this info in the foregoing but if no one mentioned it sometimes if your vent tube from the gas tank to the filler area has a sag/loop in it and if you over filled the gas tank, your vent tube can become clogged with gas acting like a P trap. This can create a vacuum situation in the gas tank preventing a good flow of fuel to the engine. The excess gas will eventually evaporate and allow the engine to run properly. Check the vent tube and make sure it"s angle will allow it will drain straight down into the tank.
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback