l83 dod delete

[ehall8702]

anyone had issues with loud injection pump after Dod delete? wasn't aware there were 2 pumps (one is labeled for 8spd trans and other labeled for 6spd trans). long story short, l86 afm destroyed it, customer bought a used l86 online and i was going to do dod delete. get engine here and it's a l83 with castings ground off! customer says f it and build the 5.3l. got dod delete cam (L8T)from MI motorsports, ls7 lifters, all that, used 6.2l intake. standard tune turned off DOD in ecm. fuel pump is kind of loud like its follower isnt pumping up, replaced then realized its a solid roller. have a pump sitting from both l83 and l86, which should be different parts numbers (this truck has 8spd and the donor motor was marked as a 2016 Cadillac 6spd) but they are identical. tried both same noises. also have about 16psi (on gauge in dash) at hot idle. was that way when i bought alignment tools and reused old pump. bought new ac Delco pump and another set of o rings for pan and changed, same pressure hot idle. on start it's like 40psi. u even breath on gas pedal jumps right to 40 psi plus, full throttle 60plus . 65mph sits 25ish. i used the Dod valley block offs, checked screen and replaced the oil switch with one from another engine. same on both, still looking for an adapter to use manual pressure gauge. i reused stock valley plate but left unplugged. i don't trust gauge on dash engine is dead quite when full hot except the slight tapping of pump, which i think is just me over thinking. owner says it's always sounded like that from day it was new on start up till it got warm. no missing, no lack of power. i worry myself ALOT bc this is my first gen 5, I've done dozens of gen 4s with zero issues, not too familiar with gen 5 sounds so everything makes me nervous lol. Anyone been thru this? i have 2 more customers wanting me to dod delete thier gen 5s , but i took a loss on this one, do not really want to get into another one if im missing something here. For reference im going to go cold start a buddy's truck and see if the noise is comparable and it's just me. First start noise was very loud as i usually throw out the foam under the intakes bc they hold moisture up here, but quickly put this one back and it's amazing how much it takes the direct injection noises out!

[ehall8702]

for background the truck had a low-end knock badly when it got towed here so couldn't hear anything but that and the donor motor was shipped on a crate, they purchased and ive never heard it run before that.

[Estep40511]

Did you follow the install procedure for the high pressure fuel pump? if not, they can be rather noisy. for the oil pump, Id say thats normal. gauge on dash isnt always accurate. the oil filter adapter will give you the true PSI. It will throw a code if theres an oil pressure concern. Only other thing It may be is lower depending on mileage, wear etc. Or, a slight knick on one of the cam bearings will do that too. ask me how I know lol

[ehall8702]

inspected cam bearings, new thrust plate, valley plugs, all the boxes checked off. as for procedure on putting the DI pump in, never knew there was one, evenly tightened it down then torqued. actually, have done it about 6 times so at least ONE of those times would have netted a different result i would have imagined lol. truck had 160k original miles, was supposed to be under 100k on donor engine but the guy selling it didn't know it was a replacement engine he pulled out of the 2018 Cadillac either. engine didn't look to gummed up so id say lower mileage, but who knows. the variable oil pump is new to me so in all honesty, old school rules is 10psi per 1000rpm, im almost 3x more pressure than required i guess. id be worried if it didnt rise so quickly under slight throttle honestly. i kept the stock VLOM, checked the filter, was clean and swapped the sensor with on i had here, same numbers. almost was thinking the valley plugs were playing with the pressure. im not gonna worry about it as long as it doesnt give me the low pressure shut engine off message and continues to sound and run like it does.

[ehall8702]

https://youtu.be/daHSBWhhl20?si=Bwjfb40H3VQC4gRN

[jmardlin]

If the fuel lobe on the cam is any more than about a +10% you would need a lash cap for the hpfp unless you are using a lt4 hpfp. Without the cap and an aggressive fuel lobe it would sound just like a normal lifter ticking. Lt4 pumps have a longer rod that is operated by the fuel lobe lifter. In some cases with the stock pump and a +10% fuel lobe you can start to hear the tick because there is little to no preload on the hpfp.

[ehall8702]

If the fuel lobe on the cam is any more than about a +10% you would need a lash cap for the hpfp unless you are using a lt4 hpfp. Without the cap and an aggressive fuel lobe it would sound just like a normal lifter ticking. Lt4 pumps have a longer rod that is operated by the fuel lobe lifter. In some cases with the stock pump and a +10% fuel lobe you can start to hear the tick because there is little to no preload on the hpfp.

that was my thoughts also but as far as ive read and been told the L8T cam is a stock L83 cam without DOD, fuel lobe should be the same. im about to put a shim in it just to eliminate this issue. i have a stock pump off of both a L83 and L86 ( which are supposed to be different for either a 6 spd trans or a 8spd trans, part # wise they arent the same tho measure out identical with micrometer).

[jmardlin]

I work for GM and the regularly change part numbers on stuff even in the same model year. I doubt there is any difference in the pumps at all. More than likely they cross reference to each other. Heck there is 4 or 5 different part numbers for the hpfp that came on the LT4 engines. Gm may have a different lobe on the L8T than what s on a 5.3 cam. My truck with a +10 lobe it has a very slight tick when you are outside the truck. You can't hear it inside.

[ehall8702]

I work for GM and the regularly change part numbers on stuff even in the same model year. I doubt there is any difference in the pumps at all. More than likely they cross reference to each other. Heck there is 4 or 5 different part numbers for the hpfp that came on the LT4 engines. Gm may have a different lobe on the L8T than what s on a 5.3 cam. My truck with a +10 lobe it has a very slight tick when you are outside the truck. You can't hear it inside.

added a .060" shim and pump STFU , as for the fuel pumps, different part numbers totally and no superceeded kinda dealScreenshot (10).png

[jmardlin]

I see what you mean now about the 2 pumps. From what I saw the 10027 was used on a wide variety of GenV engines of all sizes. The 10113 was only used specifically on 5.3l engines like it says with an 8 speed. Odd they chose to do this. The difference in 5.3 applications shouldn't make a difference in pump rod clearance as they all had the same camshaft. That L8T cam has to have a smaller base the the L83. It may or may not have more lift. That would have to be measured. I'm glad the .060 lash cap worked out for you. I may try one on mine as well.