5.3buggy

I'm trying to finish up dropping a 5.3 in my rock buggy and I'm having some problems.

What I have. 2002 5.3 with a Speartech harness and program, drive by wire throttle, TH350 tranny.

When I start it up, it runs rough almost like it is missing on three cylinders. I've checked all the connections, and double checked the grounds. Every once in a while it seems to run good for a second or two and then it goes to hell again.

I have the 02 sensors connected but not installed in the pipes, could this be the problem?

Thanks in advance

gnx7

iTrader: (28)

You have the MAF sensor hooked up and all vacuum leaks closed up right? there is a vacuum port on the TB that may be open on the driver side (copper color).

The computer must also relearn the setup for the first few minutes. I assume the 5.3 is stock?

5.3buggy

Yep, just double checked all of that. I reset the computer and it seemed to make it run better. I'm guessing that the proper reset would be leaving the ignition switch on and then removing power for 5 minutes?

After I powered it back up it started and idled pretty good. But the drive by wire throttle stopped working. I unplugged and re plugged the connection at the throttle body and it started working again. I guess I need to get some exhaust on it before I go any further.

Thanks

Remington H.

iTrader: (2)

yeah that sounds like what my swap was doing, because I didnt have the o2 sensors hooked up right and it just ran like crap, I say check your o2 sensors and make sure they are plugged in and hooked up in the exhaust.

Remington

CamaroCain

iTrader: (1)

You have to have the o2 sensor in the correct places or it will run like crap, beacuse all the read is the amount of oxegen in the exhaust system. If you do not have them in the pipes yet, just leave them unplugged, i left mine unplugged and drove it to the exhaust shop like that. I would drive it hard or rag on it without them in place, but at least the computer knows that it is not getting any readings instead of the incorrect readings.

As far as the throttle stopped working, usually with those things if the vehicle looses power it will set a code for the TB and it will be in reduced engine power which wont allow the throttle bladed to open as much(make it feel like it has quite working) until you clear the codes or cycle the key a few times til it clears the fault. Then it will start working again.

Clint

MrDude_1

iTrader: (4)

im not laughing at you, but i have to admit, i chuckled a little when i read that.


yea, it NEEDS to be in the exhaust, and the exhaust NEEDS to not have any leaks before it.


then it'll run better.. lol.



right now, the engine "sees" alot of o2 in the exhaust.. its dumping ALOT of fuel in to try to compensate, and that makes it run really rough... you may have to change your plugs after you fix the O2 sensors.... the plugs may have fouled from the extra fuel.

5.3buggy

I realize now how stupid that sounds. I've worked on a Holley Pro-jection system (crap) in the past and the engine would run "decent" with the O2 sensor not hooked up.

MrDude_1

iTrader: (4)

well, some guys on here argue that the MAF is the most important sensor on the engine... others say the MAF is worthless and that the MAP sensor is what matters..

but really, the one sensor that has the largest effect on the motor when its misbehaving are the O2 sensors.. when one is dead, the computer will richen that bank 25%... max rich trim... thats ALOT of extra fuel. the car runs rough, and the plugs will foul if left that way... with them both like that, i can see it bearly running..

you can run it with NO O2 sensors, and it'll run better then hanging O2s... but it wont run great until you get them correctly installed.