So I swap cams and go to get it tuned. Truck is running horribly under any type of load at all but it'll cruise and idle all day long. So I buy a new timing chain (LS2) and tear it down again to check for dot-to-dot and excess chain slack. Well I find that it is in fact dot-to-dot, so I drop the oil pan to chain out the timing chain anyway.

That's not a very good design, it's a bitch getting that bolt started on the bottom side of the oil pump. I reluctantly put it all back together because I know I didn't really change anything (new chain has just as much slack as the factory 135,000 mile chain). Get it all back together and find out that I must have pinched the o-ring on the oil pump pickup tube because I have no oil pressure.

I think it's time for a small loan and a 6.0...

 

what cam is it and define "running horribly"?

 

What did whoever is going to tune it say??? Could it be in the tune?

 

what cam is it?

 

SLP camshaft. 214/222 .565/.569 115LSA
And by running horribly I mean the truck at >25% throttle starts backfiring through the exhaust and running very very rough.



Wheatley messed with it for hours, just trying to get it to idle without surging…


Here’s a quick timeline:
1. Install cam. Start truck and it idles (with lope) pretty smoothly. Let the truck get to operating temp and then I give it a few revs. The truck free revs up to 5000+ RPMs no problem, and smoothly.
2. Go on the first drive after the install and I have to two-foot it, no big deal I think, that will get corrected when I go see Wheatley. First time getting on it under a load it runs pretty bad, but does lock the torque converter at 50mph.
3. Next day I drive to Houston to see Wheatley (~3hrs) the truck is still running very rough when you go over about 15% throttle and the torque converter is now refusing to lock up. On top of that the truck isn’t free revving smoothly anymore. Although the truck runs smooth at about 3200 RPMs unlocked under a very light load.
4. We eventually come to the conclusion that maybe the timing chain is too loose or it wasn’t installed dot-to-dot. So I drive back home, buy a LS2 timing chain (I didn’t replace the stock one, even at 135,000 miles), and tear into the motor.
5. Find that it was installed dot-to-dot and after replacing the chain I find that the new chain is just as loose as the stock one.
6. Start the truck after the second tear down and notice I don’t have any oil pressure, unfortunately for my dumb *** it took about 30-45 seconds of running before I checked.
7. This is where I’m at now. I’m thinking I have two problems. One is any possible damage I did to the motor while it ran without any oil pressure. And two, I need to pull the valve covers and pull the cam to see what I find. Maybe a broke spring, maybe a bent pushrod (I did replace the stock pushrods with Thunder Racing 7.400” units), maybe something else.

I don’t know much right now because I can't see much, I think I’m done messing with it for tonight. I’ll pull the water pump, front cover and valve covers tomorrow as well as the cam if need be to find my problem. O yah, can’t forget to fix that pinched o-ring….


I’m debating just starting to un-bolt the TC and bellhousing bolts and going to a bigger motor lol….. But really, I am.

 

Anybody got any input?

 

check the o ring, and use the red one and not the blue one

 

are you throwing any codes? whats the spark plugs look like? could be a scenario of things ...bad wires, maf dirty.. fuel injectors plugged slightly ...

 

Sounds like you've gotten alot of input on the oil pressure issue...

As for "running horribly", my truch ran like poo when I first installed my cam (and a tiny cam it is), until I got the tuning worked out. I was gettin 7.9* of knock retard every time I tipped the throttle. 99-00 trucks are notorious for false knock...there was a bunch of info about it a few years ago. Alot of us 99-00 guys switched to 01-02 PCM's (along with a few other mods to make them work), but in the end it solved the problem.

 

Yeah, I know the o-ring has to be the problem, the blue one came stock on my truck, does anybody have a part number for the red one?

I am throwing codes, random misfire codes IIRC. The spark plugs look great, and the fuel injectors are 8.1L units that have less then 10,000 miles on them altogether. The sparg plug wires are Taylor Pro-Race 409 units that are pretty new.

Although the truck is a 2000, it is being ran by a 2002PCM that has been tuned by Wheatley. After he messed with it we both came to the conclusion it was some type of mechanical problem.




Thanks for all of the input guys, it's much appreciated. But I'm really leaning towards buying a 6.0L and a brand new cam and brand new valvesprings and calling it a day. That way I have a low-mileage motor and I know exactly what I got on my hands.