No Start,what can cause it?

[Yukon6.2]

Hi All
So i'm looking for causes for a no start on a EFI pump.Truck is a 97 k3500 5 speed.Things i have checked ...
FSD have a known good one.
Fuel shut off
restriction in return line.
Fuel pump,relay,have it hot wired now.
And a few others i have forgot.
I erased the codes and none have returned while cranking it.
I had it plugged in for 6 hrs and was nice and warm,nothing.

The last time it was running there weren't any apparent issues.I did just change the FSD and it was working great.Tank is full of fresh fuel.
Thanks Thomas

[phantom309]

Internet guess's,.??

how do you know the fsd is good?
is it remote mounted ? hows the extension cable,.??

do you have fuel pressure?
I,m just now dealing with this issue after blowing all lines back to the tank,.
pressurized tank and flow is very good,.but pump has very little volume,..

restricting the return line will not let air get bled thru,. possibly making things worse,.

i would hot wire the lift pump and crack the T fitting to check flow,.put a clear hose on it and run the fuel into a jug,. see if you have aerated fuel,.

[Yukon6.2]

Hi Phantom
Thanks for th guesses.
The FSD was a new one from my brothers truck.
Did hot wire pump to double check flow,was still good.
Everything was normal when shut off.....
I did spend some time yesterday checking a bunch of stuff,which pissed me off being Sunday.I still have a couple of little things i need to do on my house on Sundays.
Any how my back was sore this morning,i was still pissed and i had planed on converting to a mechanical pump anyhow........
So i have a pile of DS4 stuff on the floor and everything apart.Of course it's fighting every step but i will be so happy if i can get it to run again.
Today's hurdles.....
The spot for the throttle cable was already taken by about 17 wires for all the lights ect for the tow deck....The last one before i came home was the new Mil Spec pump has a 5 pointed security headed bolt for the top cover.
Tomorrow i will find out if the lines i have will work,if not i will need to scrounge some from a friend.Then somehow i need to find a way to get the throttle cable between the dual thermostat housing and the AC and still function.The the high idle solenoid needs to find a spot to do it's thing.
Sounded so easy when it was just a future project.
Thomas

[arveetek]

Hi Phantom
Then somehow i need to find a way to get the throttle cable between the dual thermostat housing and the AC and still function.The the high idle solenoid needs to find a spot to do it's thing.
Sounded so easy when it was just a future project.
Thomas


Let me know if you find a simple solution for the throttle cable. The dual T/stat housing takes up all the room that the manual pump cable is supposed to occupy. Normally it involves modifying the thermostat housing to make it work. I think this is the toughest job when converting to manual FI.

Good luck!

Casey

[Yukon6.2]

Yea the throttle cable was a bit of a bitch....
I thought i had done it before for my 90...not the same.
I'll post some pics i did get it done day before yesterday.There is only a small window for the cable but i'm happy with it.I took today of to go buy a lowbed that i really didn't need,but it's an upgrade to on of the ones i have now.So...
For Sale Brentwood 50 ton lowbed,discounts to Dieselpage members :D
Tomorrow i build the high idle solenoid mount.I'll miss the high idle mod for the EFI pump and will probably get a cable to get higher RPM's.I'm hoping to get close to finished tomorrow.
Thomas