Motor in and running but questions

[stingray72]

Ok. motor in and running but I have one question. There is a delay starting and stopping the motor. Around 3 seconds or so. What would cause that? BTW, the truck was not installed by me but apparently my mechanic hasn't been able to figure it out

Engine purchased from Spaldings (5.3L / 4L60E)

Also did an aftermarket gauge cluster from classic isntruments and the tach isn't working so I'll be working on that when i get the truck back this weekend

Any ideas on either case and I'm all ears

[ls1nova71]

Sounds like something is keeping your ignition relay energized a little too long. Who did your harness? How are you powering it? The old distributor wire?

As for the tach, you probably need a pull up resistor to up the signal. It needs to be a 680 ohm 1/4 watt resistor placed between the signal and power wire to the tach. Also tach should be set to 4 cylinder mode.
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[stingray72]

Originally Posted by ls1nova71

Sounds like something is keeping your ignition relay energized a little too long. Who did your harness? How are you powering it? The old distributor wire?

As for the tach, you probably need a pull up resistor to up the signal. It needs to be a 680 ohm 1/4 watt resistor placed between the signal and power wire to the tach. Also tach should be set to 4 cylinder mode.
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Spalding did the harnass for the motor. i told them what I was putting it in and they did the work there. I'll have to check the truck when i get it back this weekend. Just trying to get my ducks in a row the next couple of days so I can knock this out this weekend.

Classic Industries gave me some ideas on the tach. 1000 ohm resistor from power stud and signal stud on the tack and set the dip switches for a 4 pole signal

[stingray72]

Ok. got the truck back this weekend. Drove it around all weekend in SC (where the install was done) and then driving home yesterday to Atlanta after about 100 miles the truck started to act like it was starved for gas and died. I checked fuses on the new engine harness from Spaldings and one of the fuses was blown. I didn't have any so by the time a friend brought me a fuse I replaced it and the truck cranked up again and ran fine, for a 30 miles this time, then about a mile from home it did the same thing. Like it was starved for fuel and choked out but this time the fuses were good still but the one I replaced was hotter than I firecracker. Again, after fifteen minutes or so, cranked back up and ran ok for the final mile home.

So .. can a fuel pump overheat? I can't figure out where to start checking and diagnosing this. The truck engine itself is running cool according to the temp gauge, there is fuel at the fuel rail on the engine.

[Dustytrix]

I don't know about overheating but it can get under a strain, low voltage. you should be running power to it with a relay also.

[stingray72]

Originally Posted by Dustytrix

I don't know about overheating but it can get under a strain, low voltage. you should be running power to it with a relay also.

It has a relay, came as part of the harness from Spaldings. Can I check the relay somehow?

[BR3W CITY]

YES a fuel pump can overheat. Is it an internal or external pump? FP's use the fuel itself to lube and cool the pump, so perpetually running the tank very low or dry, or mounting the pump too far or too high from the pickup don't help.

Check for FULL voltage at the fuel pump under key on, and after leaving it on for a few minutes make sure the wires to it aren't getting very hot (same with the relay itself). Low voltage will strain the pump.
If the wires are hot, make sure you have a large enough wire (and that its not randomly grounding out or cracked somewhere). I would also imagine that a restriction could also cause similar problems. If the pump were to be sucking too hard, from something like a collapsed line, being mounted too far away, overly small micron pre-filter or sock etc. The pump will still try to push, but will end up drawing more current to do so...causing the fuse to blow.

Tell me how your fuel system is setup or put up a pic.

[stingray72]

Ok. External fuel pump mounted on the frame (VPN-GSL392 WALBRO ELECTRIC FUEL PUMP) and a WIX-33737. The WIX thingy is forward of the pump. Fuel tank mounted under bed

I filled up before I left and was still reading > 1/2 a tank of gas on the fuel guage

I tested the Voltage while the truck was running at the fuel pump and got 13.2V. Now when I went to the "key on" position which I believe is turning the key 1 position clockwise like i was going to crank it I was not reading voltage at the fuel pump, was I supposed to?

Here are the pictures

[BR3W CITY]

/are your running a car intake, or is the 5.3 the newer style with no return?
If its the old truck return rail AND you are running the vette regulator, I'd think it would create weird situations with your fuel pressure....otherwise disregard that part.

Key on is the first turn to the right, after you insert the key; fuel pump should turn on (along with little things like gauge back lighting etc), and read 12v+

When you turn to position 2 (ignition) the engine would crank, you may lose the 12v for a second but usually only for a millisecond while the load is all on the starter.

[stingray72]

The engine is out of a 2009 Silverado. I'm not sure if that's newer style or not. This is what I got from Spaldings. I'll check the voltage this afternoon when the key is on the first turn to the right. Seems like it would have to have voltage or it wouldn't crank otherwise? But the truck is still cranking

THIS PACKAGE IS AN ENGINE CODE “LMG”. WHICH IS A 315 HP WITH 345 TQ IN ITS FACTORY SPEC. THIS ENGINE WILL ALSO RUN ON E-85 SO IF THAT TYPE OF FUEL IS AVAILABLE IN YOUR AREA, YOU CAN CHOOSE TOP RUN EITHER REGULAR GASOLINE OR E-85

[BR3W CITY]

I meant voltage at the pump, not all voltage fwiw. 2009 would be a new style rail, so it should be return-less (unless the flex fuel changes that).

[stingray72]

Originally Posted by BR3W CITY

I meant voltage at the pump, not all voltage fwiw. 2009 would be a new style rail, so it should be return-less (unless the flex fuel changes that).

I was testing the voltage at the pump. One man show here so I have to turn the key to the on position and climb under the truck. Got no voltage at that point, then I climbed back out, cranked the truck and climbed back under while it was running and got 13.2V at the pump. I measured both from the hot wire on the pump to the frame and to the ground stud on the pump.

[OneOffStroker]

Originally Posted by stingray72

I was testing the voltage at the pump. One man show here so I have to turn the key to the on position and climb under the truck. Got no voltage at that point, then I climbed back out, cranked the truck and climbed back under while it was running and got 13.2V at the pump. I measured both from the hot wire on the pump to the frame and to the ground stud on the pump.

When you turn the key on, the PCM runs the pump for only about 2 seconds. Then after you crank it and the motor starts, it turns the pump on constant. That may be why you didn't see anything with the key on. You would have needed a second person there, or lightning speed. Once running, and 13.2V at the pump, all seems legit.

[stingray72]

Random possibly unfounded thoughts, I'm just spitballing here ..

Venting of gas tank might cause problem? They're not vented to a canister, just trapped to prevent gas from sloshing out

Fuel lines not rated to pressure needed? Rubber right now, need braided?

WIX regulator too close to pump or too far from engine?

Power wire to Fuel Pump not large enough gauge? Or not grounded good enough? Too small fuse in fuse blow

Sending unit in gas tank the problem somehow?

BTW, the 4 relays that came wired and with the Engine were FUEL PMP, TCC, START, IGN. I'm assuming the FUEL PMP fuse was the one that was so hot but the fuses aren't labeled so not 100% which one is which. I have contacted Spalding

[BR3W CITY]

venting maybe, but I doubt it
If its not FI rubber, it needs to be replaced, otherwise it should be fine. Power wire size could be increased a bit but shouldn't need to be huge.

They didn't label fuses?

[stingray72]

Originally Posted by BR3W CITY

venting maybe, but I doubt it
If its not FI rubber, it needs to be replaced, otherwise it should be fine. Power wire size could be increased a bit but shouldn't need to be huge.

They didn't label fuses?

Not that I can tell, I'll take a picture today

[stingray72]

This is how it looks mounted up under the dash, sorry, hard to get to to take a good picture

[stingray72]

I'm still trying to sort everything out. The rubber fuel line from the tank to the pump is rated to 50 PSI. The fuel pump is 60 PSI max. There is a hard line from the WIX to the engine

Is 50PSI enough? Could the line be collapsing?

[BR3W CITY]

iirc the fuel system runs around 58psi, so the regular low pressure line you have could bulge and eventually burst, plus you'll never pass tech anywhere.

[laynrockers]

This is interesting. Do keep us updated as I have a motor + tranny that spaulding is building.

[rs72z]

I noticed a couple of things that need to be adressed also.

1 Where they grounded the fuel pump needs to be cleaned. It's grounded to paint now. This could be causing a problem with the fuse.

2 When you change the rubber hose get some fuel injection hose clamps, they won't cut the hose when tightened up.
I would run as little rubber hose as possible. On my swap i ran metal brake line as much as i could.

[stingray72]

Originally Posted by rs72z

I noticed a couple of things that need to be adressed also.

1 Where they grounded the fuel pump needs to be cleaned. It's grounded to paint now. This could be causing a problem with the fuse.

2 When you change the rubber hose get some fuel injection hose clamps, they won't cut the hose when tightened up.
I would run as little rubber hose as possible. On my swap i ran metal brake line as much as i could.

Thanks, I'll fix the ground when I take the bed off to do the hoses. I was planning on using the braided fuel line from Summit which others have used in the Swap FAQ