3400 lifter issue, TCE lifter springs installed

[Superdave]

160 T Stat is a nono, 180 is as low as you should go.


These engines operate best around 200, 180 stat gives you just enough to keep it cool at the strip and in hot weather.


Get the tuning stuff, seriously. You'll be able to figure it out, It's not that bad.

[geldartb]

i feel the need to change the thermostst because if i dont have the fans bypassed to run all the time, the heat gets to just about half, and it starts knocking, and runs like shit, if i keep it nice and cool it hallllllllsssss AAAASSSSSSSS. which is in about 1/4 temp, and it runs with the fans on at just about 1/4, and its only +8 outside lately. in traffic it gets a bit higher, remember i'm the only one here running 11.5:1 that i know of on this site, and yes i've heard of a few people having 12.3:1 but they never seem to surface

i don't remember what your end goal is with this engine but if your modding it beyond stock your going to have to tune anyways.

instead of paying someone 200 an hour to tune it take what you would spend in 3hrs and buy a tuner. assuming your going hptuner route. as far as not knowing what your doing there is a ton of material spread among the forums. i wasn't a jedi tuner when i started but through reading and working with people i got it.

These engines operate best around 200, 180 stat gives you just enough to keep it cool at the strip and in hot weather.

.

forget where i saw it but i read an article that said something about it being better to keep the operating temp around 200. wasn't about these engines but it applies.

[bob442]

My end goal was around 280 Hp, even though I'm told I didn't have enough cam to accomplish that. How ever, the motor is done as far as performance mods go. If I get anywhere's close to that I'm happy. With the cam I think I was predicted to get 250, but I'm hopping with the headers, cr, and lightened rotating assembally I just might achieve something better.

I just went for a spin with my works good scanner, and logged a few things, and left the fans not bypassed, I guess with the air all bleed out now I dont have a heating issue, I peaked at 187, and mostly hung around at 183, I only had 1-2 degree knock retard at wot, but when I get to power enrichment I start to go lean, which happens after 1/2 throttle, so I'll be gathering up money soon to get this tuned. As much as I wanted to tune this myself, I don't have the time to invest in learning how to perfect it. I'll just pay someone with years of experience to do it right. He did a pretty damin good job on a base tune with no data logging. And trust me everyone, I want to get this tuned like last week, I just have no funds for that, and I'm still chasing down little gremlins that I would prefere not to arise on the dyno


Sent from my iPhone using my iPhone at work cuz I have nothing to do

[geldartb]

you will probably have to tweak the spark table a bit if your still running the higher CR

[TGP37]

+1 on the tuning gear. I got the HPTuner package which is pricey but worth it.

Your headers have a LOT more surface area to radiate heat into the engine bay then the stock logs. So you are probably adding more heat to the engine bay, especially at mild cruise where the exhaust temps can climb high.

You might benefit from exhaust wrap and get a true cold air intake. One where the air filter is routed out of the engine bay, prefereably somewhere in front of the radiator but not too low where a puddle of water can get sucked in.

Also, make sure the radiator cap can hold the pressure (15 psi I think it is). Any loss of pressure in the cooling system will greatly lower the boiling point and might cause steam layers adhering around the cylinder walls. Another important job of the tstat, is too let the water pump pressurize the blocks coolant.


Did you swap in larger fuel injectors? I believe the stock ones max out quickly with any substantial power mods. Another reason to get a tuner, so you can put in some larger injectors and run them properly (with out jacking fuel pressures)

[bob442]

My rad cap is holding pressure, i do have a true cold air intake, and i do have larger injectors, #28 from a trail blazer, and i had the base tune done so it can run properly with them. and its at 14.7:1 till i'm in power enrichment. My valve train chatter seems to come and go, its there when its cold, gone when its warm, but i still have 2 noisy parts in the rear of the motor, its getting quieter and quieter the more i drive it so i'm not getting too worked up about it.

+1 on the tuning gear. I got the HPTuner package which is pricey but worth it.

Your headers have a LOT more surface area to radiate heat into the engine bay then the stock logs. So you are probably adding more heat to the engine bay, especially at mild cruise where the exhaust temps can climb high.

You might benefit from exhaust wrap and get a true cold air intake. One where the air filter is routed out of the engine bay, prefereably somewhere in front of the radiator but not too low where a puddle of water can get sucked in.

Also, make sure the radiator cap can hold the pressure (15 psi I think it is). Any loss of pressure in the cooling system will greatly lower the boiling point and might cause steam layers adhering around the cylinder walls. Another important job of the tstat, is too let the water pump pressurize the blocks coolant.


Did you swap in larger fuel injectors? I believe the stock ones max out quickly with any substantial power mods. Another reason to get a tuner, so you can put in some larger injectors and run them properly (with out jacking fuel pressures)

[TGP37]

My rad cap is holding pressure, i do have a true cold air intake, and i do have larger injectors, #28 from a trail blazer, and i had the base tune done so it can run properly with them. and its at 14.7:1 till i'm in power enrichment. My valve train chatter seems to come and go, its there when its cold, gone when its warm, but i still have 2 noisy parts in the rear of the motor, its getting quieter and quieter the more i drive it so i'm not getting too worked up about it.

facepalm, I forget who does what at times.

[3400-95-Modified]

Just a FYI. I have the 28lb injectors but I've bumped my fuel pressure to 63PSI which makes them around 30lb/hr to support my setup, so I would just verify your Injector Duty Cycle sometime. I would also not be driving this if your tune is that bad. I had to do a quick one for robert and I kept his on the richer side of things... IIRC he is getting around 12:1 AFR or maybe a bit more. I did that since he needed to take the car home for the winter. I'd rather see him be a bit down on power till we finalize it rather than knocking at WOT and blowing something up.

[unchained01]

So what's the last word on this is an oiling problem , too low viscosity oil , worn out lifters ? Sorry to be a pain in the ass I have been following this daily and lost track dammit. I have a set of liters with those springs I. Them also and would rather buy a new set and install them in those than go thru this .

[TGP37]

3400-95-modified has a point about fueling. Better to run a little rich then blow a rod into the pavement.

Are your fuel trims near 0 at lower throttle/idle?

A failing EGR can make the exhaust appear to run richer then what it really is. (stuck open)

The one thing about higher fuel pressures is the flow rate goes down in proportion to the pressure rise.



I just thought of something.......your fuel line, is it stock? I had to put in a 3/8"ID line to support the fuel flow. Skinnier lines reduce over all pressure at the injector. If you installed a larger line, you will naturally see more pressure at the injector. But not much more. But the flow rate max will be much higher.

Since the fuel is leaning at the top end and you have larger injectors, maybe a restriction is the problem.

[mfuller]

Just a FYI. I have the 28lb injectors but I've bumped my fuel pressure to 63PSI which makes them around 30lb/hr to support my setup, .....

I could be mistaken, but I thought that 28# rating was for the Trailblazer I6 application, which has a rail pressure of 62psi. So you're probably not getting quite 30#/hr.
A stock 3400 FPR is 55psi, so using those same injectors as you have, I have the injector constant in my car set to 26.37 (I think) in HPTuners.

[geldartb]

A stock 3400 FPR is 55psi

slight correction on that 00+ is 55psi and before that was 43.5psi.

[bob442]

It's goes way rich on power enrichment, I got confused, it goes down past 11.7:1 when I floor it. So I'm sure I have figured out my lifter issue, I'll know probably later today for sure, but I think 2 check ball spring s have to much seat pressure. I'm going to have to swap to the stock springs. I don't know what I'm going to be loosing swapping to them, but there is no other reason 2 lifters are not pumping up after I have changed them and swapped the springs over yet again this weekend. I have inspected my lifter bores and oiling holes, so its that, or really week valve springs. I spoke to a retired mechanic friend of mine, and told him my delema, and he said that inertia spring rate has to match, and when there is a "bad lifter" it's usually the check ball spring inside, an not always the lifter. As lifters are hydraulic, they rely on mechanical forces to function properly. So I guess I got delt 2 bad springs out of everyone, and shit happens.


Sent from my iPhone using my iPhone at work cuz I have nothing to do

[TGP37]

Make sure the EGR is working properly. I've read a stuck open EGR can give a false rich signal, due to less o2 in the intake.

But at least your on the rich side of the fence.

[bob442]

not worried about my EGR http://s15.photobucket.com/albums/a3...inalcut009.jpg