New owner of 5.3 swap...few questions about Vortec Voodo

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I have had several mini trucks linked and it's glorious. I am assuming you have not been in a properly linked rig on washboard terrain etc. amazing articulation, ride quality, axle location and travel and adjustability. Its an evolutionary process and I believe it's a superior way to suspend the axles.

Georg, I totally agree however there are many ways around that issue. The 80 series and all modern jeeps get around just fine linked up.
 
Something rubber on a DD for sure to help isolate some of the harmonics transmitted back.

When I say linked I meant the use of linked suspension in the stead of springs...sorry for the confusion.
 
This just popped into my head from a thread in our local club forum but...

Maybe the hard starting and pressure loss in the fuel system are related. Maybe you have an injector leaking down that is flooding a cylinder making it hard to start? do none of them fire, or does it stumble till it starts?
 
Rover:

I have not looked at any vortec data as of yet regarding fuel pressures and such after shutdown. I will say that I have an inline gauge installed just before the fuel rail and pressure drops immediately after shutdown.

However...if the rig is cold (I am assuming still in its warmup idle tables) it will crank right back up again.

If I have been driving around a bit it can be harder to start (say grabbing some milk in the grocery and restart shortly after).

I am keeping my eye on it simply because all day yesterday she was running very very well and I made several stops running errands and she never failed to start properly although there were a few instances where it took a few extra cranks.

Another thing worth noting is I am alowing the fuel pump to prime the fuel line before I crank which obviosuly helps things.

What I would like to know is if a check valve would help the system from "backflushing" or whatever to the tank or should that be the job of the pump...to hold line pressure after shut down?

And finally, it has been having much better restarts after fixing the evap fiasco however the charcoal can is still no good because it had been flooded with liquid fuel...a new can is on its way via fedex for install tuesday.

I am assuming the hard starts are in direct relation to the evap system sampling higher than normal fuel vapors and compensating by adjusting the Pulse width modulation of the injectors etc to compensate for the vacume loss attempting to purge the canister.

Now of course, most of that is meaningless drivel I imagined in my mind, but I also found some light reading about how the toyota systems work and why they fail. A saturated evap box can cause such issues.
 
By the way. I just realized that of course the fuel pressure will drop to zero after shutdown because of the return system for the fuel.
It looks like it has one of the 99 corvette fuel filters with a built in "regulator" or what I call a poor mans fuel return.

SO it makes sense that it is dumping fuel pressure after shutdown but does not explain a difficult start after warmup etc...

yada yada.... I know.... In tank GM pump is the answer :)
 
AKFJ80 said:
By the way. I just realized that of course the fuel pressure will drop to zero after shutdown because of the return system for the fuel.
It looks like it has one of the 99 corvette fuel filters with a built in "regulator" or what I call a poor mans fuel return.

SO it makes sense that it is dumping fuel pressure after shutdown but does not explain a difficult start after warmup etc...

yada yada.... I know.... In tank GM pump is the answer :)
Click to expand...

that's the same filter/FPR I have and it holds pressure fine. I do have a gm in tank pump tho.

it would hold pressure before even with my many inline external pumps too.

Sounds like your injectors are fine, it was kind-of a long shot.
 
No I appreciate the info. And it very well can be something like that. I got an ultra gauge in the mail a few days ago and have been playing with that.
 
Are you going to keep the 60 axle when you link it up? 3 up front and 4 rear or what? Currently I'm running a TBI350 4l60e AA adapter stock Tcase stock rear axle. I just can't make up my mind on a rear axle and don't want to link it until I do. I almost want to switch both axles go disk brake all around and then link it but I'm not that into 4 wheeling as most of my offroading is done on a mx and desert bike. I defiantly want it linked for the ride I just don't know if the 60 axles are good enough to invest the money into linking them.
 
EFI fuel pumps usually have a built-in check valve so the system should hold some pressure. Might try capping the line before the engine, but after the filter/regulator and see if it hold pressure then. At least then you'll know which end to look at further.
 
I'm fairly sure one of the GM shop manual tests for the fuel pump is to check pressure (engine off) for a period of time... Don't think it should drop off to zero quickly.
 
Kurtis said:
Are you going to keep the 60 axle when you link it up? 3 up front and 4 rear or what? Currently I'm running a TBI350 4l60e AA adapter stock Tcase stock rear axle. I just can't make up my mind on a rear axle and don't want to link it until I do. I almost want to switch both axles go disk brake all around and then link it but I'm not that into 4 wheeling as most of my offroading is done on a mx and desert bike. I defiantly want it linked for the ride I just don't know if the 60 axles are good enough to invest the money into linking them.
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I will be keeping the cruiser third as I feel it is plenty strong for my needs. However I will be going to a centered housing from ruff stuff specialities because it is built locally and beef. I will then be running an atlas 4 speed with the typical party mix of gearing options.
The 60 axles are the only part that make me slightly nervous however sf rears seem to hold up just fine for many people...even the cummins guys.

ntsqd said:
EFI fuel pumps usually have a built-in check valve so the system should hold some pressure. Might try capping the line before the engine, but after the filter/regulator and see if it hold pressure then. At least then you'll know which end to look at further.
Click to expand...
That is an excellent idea and I will look into that tomorrow. The fuel pump does not make the pressure gauge move with ignition on, it. Only reads 60-70 psi after engine startup.
Elbert said:
I'm fairly sure one of the GM shop manual tests for the fuel pump is to check pressure (engine off) for a period of time... Don't think it should drop off to zero quickly.
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I agree. It did it again this evening ( hard start after highway) however it did start after quick re crank. The solution is close.
 
Just came across some info new to me. Apparently one symptom of air in the EFI fuel supply lines is an near instant loss of pressure on shut-down. Even if there are no drive-ability problems there can still be air in the lines. So suggest bleeding the system. Is there a Schrader valve on the fuel rail? Perhaps jumper the pump relay to keep it running and see if you can purge some air from the system.
 
ntsqd said:
Just came across some info new to me. Apparently one symptom of air in the EFI fuel supply lines is an near instant loss of pressure on shut-down. Even if there are no drive-ability problems there can still be air in the lines. So suggest bleeding the system. Is there a Schrader valve on the fuel rail? Perhaps jumper the pump relay to keep it running and see if you can purge some air from the system.
Click to expand...

I will definitely look into this. There is no Schroeder inline however I can add one and see how things look.

I'm trying to find a good Walbro pump right now simply because I would like a spare on hand (I do not trust the msd pump and it's very noisy) and I simply don't have the time presently to go in tank pump. I read someplace the Bosch external units on turbocharged cars are extremely reliable, researching this more.
 
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