Help needed...What should I do next?

[mikeheff]

temp on tech II reads 188 degrees, dash reads right at 200 ish.. grounds from motor to frame appear good, I need to check the one on tstat, didn't know one was there, thanks..can spider injectors , intake or throttle body cause this?

 

[mikeheff]

I will check it out , thanks for helping !!

 

[SunlitComet]

the tech 2 is showing you the one on the thermo housing. that feeds the pcm. so that one is at 188. the dash reads off the left cylinder head so it is not to far off then i would suspect something. do you have a wiring diagram to all the sensors to ensure you are isolated from any faults.

 

[mikeheff]

I have them, but understanding them is my problem. I have had the gm guys at my work look at it several times, they are stumped as well. Their guess is another sensor is causing the issue, something that does not require a 5 volt reference

 

[mikeheff]

the wires at the tstat housing are secure, a little green in color, but not corroded like you would see on some battery terminals..no fuzzies or anyting

 

[mikeheff]

today I spent another few hours just piddling on this thing, I cleared codes, figured I would start unplugging sensors to see what made a difference. After unplugging mass air flow, it runs 90% better. No Tps codes set for the first time, trans shifts normal and actually accels great. Thought I actually fixed it when I replaced the mass air flow sensor....NOT...tps code P0122 now, was po121..same symptoms as before. I unplug mass air and runs ok....any ideas. I really like this Tahoe, BUT, I'm at my wits end

 

[mikeheff]

today I spent another few hours just piddling on this thing, I cleared codes, figured I would start unplugging sensors to see what made a difference. After unplugging mass air flow, it runs 90% better. No Tps codes set for the first time, trans shifts normal and actually accels great. Thought I actually fixed it when I replaced the mass air flow sensor....NOT...tps code P0122 now, was po121..same symptoms as before. I unplug mass air and runs ok....any ideas. I really like this Tahoe, BUT, I'm at my wits end

 

[mikeheff]

today I spent another few hours just piddling on this thing, I cleared codes, figured I would start unplugging sensors to see what made a difference. After unplugging mass air flow, it runs 90% better. No Tps codes set for the first time, trans shifts normal and actually accels great. Thought I actually fixed it when I replaced the mass air flow sensor....NOT...tps code P0122 now, was po121..same symptoms as before. I unplug mass air and runs ok....any ideas. I really like this Tahoe, BUT, I'm at my wits end

 

[mikeheff]

has anyone ever experienced this before?

 

[mikeheff]

I have unplugged every sensor I can think of, maf, iac ,iat, egr, its runs better with any of these unplugged and the tps code does not come back unless I plug the one I had unplugged back in. Any ideas?