New user, need help on 2000 Silvy

[Telco]

Hi - New user here. I've got EFI V2, and am tuning 2000 Silverado 5.3L RCNB 2WD. I'm finding my way around the program OK, but unfortunately don't have a lot of time to tune this truck. The truck belongs to my dad who lives about 2 hours away, and I have about 2 weeks to get this done before I have to return it to him. The main reason for my borrowing the truck is so I can take my own off the road, so I'm doing 2 things at once here.

Anyhoo, I need to tune the truck for better fuel economy when cruising, and I need to adjust it to not shift gears so soon under WOT. I've found the fields to adjust the trans, but don't know what direction to take them. Essentially I'm looking to tune the truck so it can be two different vehicles at once, an econobox under cruise that shifts seamlessly into a performance vehicle when the hammer drops. When there is a conflict, it needs to go to the economy side.

What tables will I need to tune, and what direction do I need to take them in? Or, what tutorial do I need to be reading to find out what fields to adjust? This looks simple enough to figure out if I had more time, wish I did because this looks like it would be a lot of fun. I've already saved the baseline program so if I screw up it's an easy fix. Any assistance would be appreciated.

[cmitchell17]

Hey ive got a 2000 5.3. You can take a look at what ive done to get some ideas.

For fuel economy, since you can't do lean cruise, you can lower the O2 switchponts. This just makes the computer run in a rich mode more of the time. So it will lean out. You can copy my settings but you might find detonation under load when the TC is locked.

There is also something about changing the boundries I heard but someone else will have to tell about that.

Ive been trying to figure out the best timing for years, but it looks like the optimal timing table is good to follow. The timing I have is a blend with the HO timing table and the toptimal timing. The Fuel Mixture Spark Correction table is lowered some so my timing won't go to high.

You can lower the AFR to around 12.5-12.8. And make sure you take off the PE delay mode, and raise the shift points a few hundred rpms.

Let me know how it goes.

Since you have a 2000 like mine, what do you see for delievered torque? Does you tranmission clunk when downshifting when on the breaks?
Does it give a hard 2-3 shift at low throttle?

[Telco]

I've just had the truck a week now, but am not happy with how the trans shifts. That's something else I'm going to be addressing. I've not pulled any data logging yet either, I'll be trying that this weekend. I wish I had the time to take a couple of years on this one, but my dad is on vacation for about 2 weeks, and I'm using his truck to both let me take my own truck down for soundproofing (yanked the entire interior, including the dash, yesterday) and to do the tuning for him. I'd love to see a completed tune file from someone who's truck is running well. I'll take a look at the stuff you suggested though, will get a data log to decide what needs to be tweaked.

[cmitchell17]

Is the truck stock?

I got tired at the hard shifts and decided to go back to the stock pressures but still keep the pressures high at high torque. The shifts don't seem smooth anymore.

Im thinking It might be the slip yoke becuase theres a TSB for it and theres a nickel plated one avalible to to fix clunks. But since you have a regular cab you woudnt have one.

[1FastMax]

I've got one i think you might like, email me at camjet515@aol.com and i will send it your way.

[Telco]

Email sent, thanks.

[Telco]

K, I've got the trans worked out, more or less. With a 2000 Camaro 5.7 tune in the high octane tune and the stock 5.3L tune in the low octane table, it seems to run pretty well. I did discover that the high and low octane tables were the same for both vehicles, at least off the ones I'm looking at.

I'm going to be taking a nice, long drive Monday to see how the mileage is, so far the power is a lot better. I've got to beat 19MPG with this, ideally I'd like to get 24-25MPG just off the tune.

Power-wise it's pretty nice. The truck will now spin the tires all the way through first into second. If I am cruising at 30-35MPH it'll kick back into 1st and more rubber's gone. Nail it at 65-70MPH and it pulls back into second and hauls ass. I moved the spark tables and the O2 sensor info over and nothing else for the engine, specifically.

1FastMax, I appreciate the tune, but your truck is an E85 engine, and I'm not sure how well the tables will translate over.

What I'd really like to see if anyone has one to spare is a tune for a stock Camaro that has been tweaked with improved mileage. Reason being, I was reading an article that was discussing GM's new fueling and cylinder deactivation concepts with a GM engineer, who mentioned in passing that the trucks were programmed differently from the cars. The fuel/spark for the cars is optimized for mileage, while on the trucks is set up more for pulling loads without melting down. I figure I can put a car's tune into the truck and have a high mileage screamer (it's a screamer now compared to what it was) then just tap the tow/haul button when it needs to be used for a truck. I wish I knew where I read the article, but I was in the doctor's office and my mind wasn't completely on what I was reading. I didn't even get what I was reading till 2-3 months later, during another discussion on fueling.

[cmitchell17]

Are you running 87 octane?

it might have been taking about PE enable tps but that's at about 80% on trucks.

The O2 switchpoints get a little high at the higher airflows but only to about 620 or somthing from 450.

Look at my tune where I lowered the o2 switchpoints.

Let me know how it works.

[Telco]

Wasn't happy with the tune on the trip. Decided to try CMitchell's tune on the high octane with the factory low octane tune. Mileage was exactly the same, 19MPG, driving the same way as the factory tune. But, the engine ran kinda choppy with this tune. Thanks anyway CMitchell, but it looks like the setup I'm tuning doesn't like your tune. No idea why that might be. I'm going to try playing with it and see what turns up.

[cmitchell17]

Whats your mods?
Was there KR?

My tune is probably going to be very lean crusing and it will have between 1 an probably 3/4 degrees advance.

Ive tried a long time messing with spark and each time I test it it is so different. I finally figured that 28-29 degrees peak is best timing and the optimal timing table is the optimal timing.

[Telco]

No mods, truck is 100 percent stock other than the EFI tune. No knock retard detected, course I still need to figure out how to get the scanner to monitor the truck.

[cmitchell17]

Did you zero out the burst knock tables? That will keep that wierd knock down I bet, even though it is desinged to prevent it in the first place.

How is the power with that timing?

[Telco]

Not having a knock issue that I'm aware of. Power has been good, I've had one tune that let me spin the wheels through first and into second :muahaha:. The 1-2 shift is pretty worrisome though, the shift is really long. I put some of the TM back in until I figure out what's causing the shift to take almost a second. But, it's amazing how much power it's gotten with what I've done. Now that I've got the transmission working the way I want, I can start putting some serious effort into maximizing power and economy.

[cmitchell17]

The 1-2 shift on the truck 4L60s will never be really hard.

My 95 would do the same thing. You will need a servo if you want a hard 1-2 shift.

If you mess with tm you can get a pretty decent 1-2 shift with just a little TR and a lot of pressure, but with no TR it won't handle it nicely shifting at almost 6000rpms.

What are your deleivered torque readings?

[cmitchell17]

Take the force motor current down on the 80+psi of the table. Use the settings from a newer truck's force motor current table.

This will help a little because the 2000 table is high on the high psi regions.

You can ramp the pressure up to max(90-96) at your highest delievered torque. You might can try my settings if you want.

[ScarabEpic22]

For trucks, get a Vette 1-2 servo, its cheap (like <$15 for the part) and can be installed pretty quickly (especially if you have a lift and trans jack). Or pay some shop a little to install it. Much better 1-2 shift, I have been putting some TM and shift time back in b/c its so hard.

[Telco]

Thanks folks, I'll look into doing these things.

[cmitchell17]

Anyone who has had hard shifts for a long time:

have you noticed that it makes slak in your driveline. Like it will make your shifts sometime feel hard at low throttle and make it feel like when you put it in drive it feels like it bump into drive twice?

And does it make your downshift feel hard to. Thw downshifts when you are on the breaks? Like it bumps you forward.

I think this might be the reason my truck feels like this. Becuase my 95 4L60 shifted way better than my 2000.

[snoxracer247]

cmitchell17 im new to the forum and this is my first post, but i was wondering if your 2000 5.3 tune you have for a silverado will work in my 5.3 2003 gmc yukon,l because im lookin for a tune really bad.
thanks in advance

[cmitchell17]

Yeah, it will work but you might need a higher octane gas, im trying to get my tune to runn on 87.

[snoxracer247]

yea i was thinkin about usin 93 octane, i will let you know how it works,
thanks