No rev or throttle

[tbr89gmc]

I have done a 5.3 swap with a hot cam in my 1995 4x4 chevy truck. It has a manual trans and transfer case. I hope that ya'll may be able to help me out. Heres my problem. When you first crank the engine you can rev it for about 2 min after that it just chokes itself out when i try to rev it. IF I hold the throttle in a certain spot it just surges like its getting gas then not. Ok so I take pin 32 and 34 on blue connector and apply a ground and i have my throttle back. I tried to find some info on this and everything I find saying the vss not hooked up. I belive I do since my speedometer is working. Does anyone know what im doing wrong. Thanks for your help and time By the way this is my first time asking a ? I've done all this project by searching on this site but didnt have any luck with this one

[RedHeartbeat]

you have an O2 issue. Replace them both or buy one new one and put it on one side, if the problem continues move it to the other, if it continues replace both. Two minutes is time for it to warm up and enter closed loop mode and get feedback from the 02s to correct the fuel ratio and they're getting bad readings.

If you have a scanner that will show you the readings and you understand the voltage feedback readings you can quickly figure out which sensor is bad.

[haveTBIwantLS2]

yah man, that's your O2 sensors. The old engine in my 91 (350HO, TBI) would always go into lean surging at idle so I finally said screw it and set it to idle in open loop. I think it was the cam, tho.
anyway, I think redheartbeat is on the money (that's a shocker).

check for any pinhole exhaust leaks too

about the vss thing.
your 95 has a DRAC in it (which you probably know already) which takes the VSS hi/lo data from the VSS itself, then spits out data to your cluster and Cruise module and the '95 PCM.
If you spliced into the VSS wires (purple/white HI green black LO) feeding your DRAC to feed the 0411 computer and then fed your cluster the data from the 0411 you should be good.
If you didn't give the 0411 the HI/LO VSS feeds, your 0411 won't know how fast its going and you might have a problem.
I'm not 100% on how the manual trucks get their VSS data, but I bet it still needs the feeds

[tbr89gmc]

I bet your right. I didn't think about that. I have the black rectangle end o2 harness but couldnt find the o2 i needed so i found the diagram for the white square end and wired them in. Guess you cant swap them around like that if you can could you explain

[RedHeartbeat]

the pcm sees a reading feedback from the 02 sensor that says lean so it adds fuel, still says lean adds more fuel, still says lean so adds more fuel.... shall I go on? LOL

[haveTBIwantLS2]

yah, that could be the prob. Make sure you get the exact same year O2's.
like with my setup, for example, there were two kinds of O2 sensors (I'm talking pre-cat) for the LQ4 in 2002 (and prolly other years).
Isolated ground sensors vs case grounded sensors...different plugs (black 4 pin square vs white 5 pin trapezoid plugs)

got all that from http://www.lt1swap.com/vortec_o2_sensors.htm

[tbr89gmc]

LoL I understand that. I was asking if you could wire in a different o2 than what supposed to be used on the harness. Example if you had a harness with the black ends can you wire up white ones?

[haveTBIwantLS2]

Example if you had a harness with the black ends can you wire up white ones?

I wouldn't...
they work differently

[tbr89gmc]

Ok then. It allways bites you in the butt when you "THINK" you know what your doing LOL

[pl4yboy]

I wouldn't...
they work differently

As long as they are the same # of wires and such, it should be no problem. A lot of people like to swap over to the vette o2s, no issues doing that. Just need pinouts to see which wire needs to be where.