LLY: Reg Cab lly project

NinjaMax

WTF!
Oct 3, 2012
1,266
0
36
41
Severance, Colorado
found a regular cab for sale in Denver for 5k, its got 230k miles on it and you can tell its been put through the passes. I talked the guy down to 3800.00 and loaded it up and brought it home.


Issues,

Truck will crank like crazy but wont fire, I gave it a small wiff of either to load it and it fired up. it idles smooth until you give it a little throttle then it has horrible what sounds like injector knock. The guy I bought it from didn't speak much English and didn't seem to know much of anything about the truck. Before I loaded it up I noticed the fpr was unhooked but didn't say anything.
the truck also doesn't like 2ng gear, something im hoping is the nsbu switch doe to the "range inhibited" flashing on the dash.

Codes when I got it home
P0732
P0841
P0090
P0088
P0841

The truck had a airdog but was missing when I picked it up, which I didn't care about but it had a filter delete kit. Currently im trying to figure out the no start issue.
So far: Installed a new regulator pig tail, replaced the FPR, installed a new fuel filter, rebuilt the filter head, double checked the rub spots in the FICM harness, checked all inline fuel lines, and reflashed a stock lly tune file...still a no start.

Truck is commanding 7k and only seeing 750 psi when cranking. It is idling at 5500psi.

Balance rates
#1 -4
#2 -4
#3 +5
#4 -4
#5 +1
#6 +3
#7 +10
#9 0

When i gave the truck a little throttle (5%) the actual when up to 19k psi while desired was only 8k..it got worse the more throttle i gave it.

The truck is deleted with a strait pipe, and has a CAI installed. according to the dude everything else is stock.

When i get back from dinner im going to check the injector harnesses and just for fun might replace the glow plug relay.
Anything else you guys can recommend before i call it the injectores bing f*** up?

havent been on in a while, hope everyong is have a good thanksgiving!!
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
5,028
240
63
At Da Beach
ya, that's priority 1 when I get back.

will a bad connection at the injector cause a "no start" condition? fuel system troubleshooting is new to me..so any help is appreciated...

oh and I got an 18 denali 3 months ago...your up big guy:thumb:

Waiting on the 20...:hug:
 

Burn Down

Hotrodder
Sep 14, 2008
7,093
28
48
Boise Idaho
Injectors are returning to much fuel would be my guess for low rail pressure... I question how long it was ran with no fuel filter? I would do a compression test and decide if its worth a complete fuel system or needs a total rebuild, either way the price was right:thumb:
 

NinjaMax

WTF!
Oct 3, 2012
1,266
0
36
41
Severance, Colorado
Injectors are returning to much fuel would be my guess for low rail pressure... I question how long it was ran with no fuel filter? I would do a compression test and decide if its worth a complete fuel system or needs a total rebuild, either way the price was right:thumb:

I'll grab a tool on the way home and get that done, good a time as any! Can 1 injector cause a no start?
 

Burn Down

Hotrodder
Sep 14, 2008
7,093
28
48
Boise Idaho
If it's bad enough maybe 1 could do it but unlikely, probably multiple injectors... As NC mentioned ice pick all the injectors and make sure that 2 and 7 aren't pulled to tight. I have not seen bad connectors cause low rail pressure but definitely makes them run like poo.
 

C_Burt96

New member
Nov 22, 2018
1
0
1
Salt Lake City
If its injector knocking usually means they are stuck open. Usually with harness issues the injectors will default to closed. Might just have a couple stuck injectors. But even then it still should fire.
 

NinjaMax

WTF!
Oct 3, 2012
1,266
0
36
41
Severance, Colorado
Let's see some pics of this beast. I have a 03 being converted to LLY and shortbed with a ZF6 sitting in the garage.
Heres a few, I'll post up some of the hack job stuff I found tonight...its...impressive to say the least
4672fd036f0d2a89ae2933302953042b.jpg
aeda137cdb2505c4b4c3a61bc8b3f3b1.jpg
450dcd97775357bcdd9d616d6285da7a.jpg
ce8e8522e4174884f0d0d29225dd18b0.jpg
517be9ee2ab5298f300bf038e99c5725.jpg


Sent from my SM-G960U using Tapatalk
 

NinjaMax

WTF!
Oct 3, 2012
1,266
0
36
41
Severance, Colorado
Compression test checked out at ~320 psi on all cylinders...I'm going to finish picking the injector harness and go from there. What's the best way to test the #7 injector or any of the harness for continuity?
 

NinjaMax

WTF!
Oct 3, 2012
1,266
0
36
41
Severance, Colorado
well, picked harness and replaced the two fuel lines coming off the to the FICM. Still a no start, i gave it a quick wif of starting fluid just to see if it made any difference in balance rates....strangley enough the balance rates improved overall excepty #3
#1 -5

#2 -2

#3 +7

#4 -5

#5 +1

#6 +3

#7 +4

#8 +1


In gear, break on
#1 -5

#2 -3

#3 +5

#4 -5

#5 +1

#6 +3

#7 +4

#8 +1



Ill test the return rate in the morning just to see what that tells me. Also im not sure if it was my computer or what, but i was unable to read balance rates for a while but the rail pressure was showing. Not sure if thats an indication of something or not. Again like yesterday any throttle at all the actual was way higher then commanded, all of this was done with the regulator plugged in.


any ideas?


edit: it also idled much smoother, and also no codes from idling. i gave it a little throttle and it felt smooth, still actual is nowhere near commanded...
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
5,028
240
63
At Da Beach
Do return test and I'd run a bottle of B&G injector cleaner thru like we do the GM stuff. You can eliminate fuel system issues down stream also, if it runs better off bucket of fuel... Lol...:hug: