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03 chevy pickup problems

buffblazer

buffblazer

1/2 ton status
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hey guys i have an 03 single cab short bed 2wd chevy with a 4.8 in it. I recently aquired a transdapt throttle body spacer from another truck and decided to swap it on. well its installed and no leaks everything is tight so its good to go. well i took it on a test drive and the truck has Driver information center and it will tell me my instant gas milage, well before the throttle body spacer i was averaging 22 now its down around 19 and the performance is not all that great, i went from roasting the tires from a dead stand still with no effort to having to power brake it for a little bit just to get them going. so whats my problem? i only drove it once so do i need to wait for the computer to get use to it, and also if it makes any differance the tbs was off a 03 6.0
 
take it the hell off. Those things are a joke. They add NOTHING to that engine. All they add is extra volume to the plenum area, which is something that the LSx truck intake manifolds don't need! Longer plenum is just hurting your low end torque on an engine that needs it.

Don't trust that information center, I'd heavily bet it isn't accurate. Do your own calculations. Sell the spacer to the next person down the line.

The only purpose of a TB spacer on an LSx engine is for a nitrous setup IMO, and then there are companies making nice spacers that go between the TB and the intake tube for that so they don't affect the intake volume.
 
so is it hurting my engine to run with it for the week? im not gonna be able to take it off until next weekend and i drive 70 miles round trip everyday for work.
 
Older TBI engines that run a wet manifold charge do benefit from a spacer, just like a carb, but multiport injection engines with a dry intake charge do not help at all.

If anything, you're messing with the perfectly tuned intake geometry as GM intended it to be, which could quite possibly be the cause of your loss of mileage.

And no, it won't hurt anything but your mileage being on there.
 
i have the K&N and the exhaust goes on next pay check, what programmer would yall recomend? and also since its a bad idea for the TBS what would yall recomend for better gas milage all together, other than the programmer, k&N, and exhaust?
 
gmc4cw said:
if you want to increase the flow of air you need a bigger throttle body.

http://www.autopartswarehouse.com/performance/brand.php?makeid=10&modelid=125&year=2000&partid=33

have you already done the basics of a cat back exhaust, reprogrammer, and k&n intake kit?
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Don't put on a bigger throttle body either. Waste of time. It will still only flow as much air as the intake allows. If the throttle body opening is bigger than the intake opening for it, what have you done? It may make a slight power increase, very minor at best, absolutely not worth the $$ IMO. Unless you are looking to go serious, and then you will need to do an intake manifold swap, + accessory drive changing, and waterpump modification. Believe me I have a 5.3L about to be dropped into a 1969 Firebird with an LS1 intake manifold on it, things have to change.

Reprogramming is THE way to pick up power on those engines. Not even performance programming, just elimination of Torque Management. Items like the Predator Programmers from Diablo Sport will allow you to eliminate Torque Management and Speed limiters without increasing spark timing(which then requires the use of 93 octane). Figure if you are worried about fuel mileage, you won't want to be spending the $$ for 93/92 octane.

Factory exhaust isn't very restrictive at all. It just doesn't have the performance sound.

Leaving the spacer on for the week won't do anything except possibly hurt your mileage, and power production, so don't worry about it.
 
buffblazer said:
i have the K&N and the exhaust goes on next pay check, what programmer would yall recomend? and also since its a bad idea for the TBS what would yall recomend for better gas milage all together, other than the programmer, k&N, and exhaust?
Click to expand...
Fuel mileage worry? Eh, light foot is all I can say. K&N and exhaust aren't doing much to increase mileage really. A little, but not much. Programmer won't really help mileage either, just power production.

I recommended the Predator Programmer. I've had trouble with them, and I've had good results too. Overall I like them. But like I said, their performance tune will require higher octane fuel. Just removing Torque Management doesn't require an octane increase. It won't actually increase power, just give you more of the power you already have.

Short of full on custom tuning, I like the Predators. I've had a VERY bad experience with the BullyDog programmer on an 8.1L. 5 miles after install the engine blew a rod through the oilpan! I don't want to say it was the programmer because I don't know why that thing would cause the problem, but the program was reinstalled after I put a new engine in the truck and it ran like crap, so it was immediately shut down and the program removed. No idea if BullyDog ever commented on the issue. I was working at the dealership when all this happened so he wasn't a direct customer of mine.
 
I installed a K&N fipk kit, a flowmaster cat back exhaust and a hypertec reprogrammer all at once and picked up 2mpg. If I program it for 91 or higher octane I get even better fuel economy but pay more for the gas. I can't seem to cinvince my wife that even though the 93 costs more I get more miles per dollar.
 
So what kind of a TB spacer is it? I dont mean brand name but what type?
Is it closed or open plentum.
Closed plentum has 2 holes and will help low end torque and throttle response by increasing runner length. may help fuel milage.
Open plentum has a cutout between the holes and is for top end. They will usually kill low end torque and gas mileage.
Transadapt makes both kinds
 
Thunder said:
So what kind of a TB spacer is it? I dont mean brand name but what type?
Is it closed or open plentum.
Closed plentum has 2 holes and will help low end torque and throttle response by increasing runner length. may help fuel milage.
Open plentum has a cutout between the holes and is for top end. They will usually kill low end torque and gas mileage.
Transadapt makes both kinds
Click to expand...
You aren't thinking correctly.

LSx Gen III small block engines are all single bore throttle bodies of varying sizes. There are no twin bore throttle bodies.

Not to mention the intake manifold is a completely different concept. It is just not anything like a TBI throttle body and intake manifold.
 
Probably what happened is you did a couple of full throttle romps and that what brought your fuel mileage down. Also, you need to (if you aren't already) reset the fuel economy in the DIC. I couldn't count how many times a customer would complain of poor fuel economy (as read in the DIC) and there was nothing wrong with the truck. Just reset the DIC and back to normal. The longer the average, the worse the fuel economy.

I don't see a problem with keeping it though.
 
If he feels a seat of the pants loss of power(the power braking thing), I see the problem.

Just my opinion really, but the truck intakes already push the boundaries of what is needed for the runner length and plenum volume, no need whatsoever to increase it.
 
ya i reset the dic and i was still getting worse milage. i took it off yesterday and im back up to where i use to be, cleaned out my MAF sensor just to double check and make shure no K&N oil was on it, it looked good to me but still cleaned it. as for power i gotta make the gas last until next pay check so i havent really played yet. probably might go out and spin them a couple of times just to see. now let me fix my oops. when i said better gas milage i ment more power without lowering my current fuel milage. doesent necessarly have to go up as long as it dont go down. now i understand there is a fine line for power to fuel milage trade off but i will take any advice. all of ya mention programmers not really helping fuel but nothing about losing it so i like that idea.
 
Programmer will be the best seat of your pants improvement I bet.

Any of the bolt ons you can do to that engine will increase power without hurting mileage. You won't start hurting mileage until you are throwing more fuel at it and on the throttle all the time. So unless you are building a 402 stroker motor with LS7 injectors, you're fine.

Like I said, personally I would just reprogram it to remove the Torque Management and speed limiters and then leave everything else stock.
 
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