ok anyone here ever have this issue before? 04 monte carlo ss l36 engine.

I am having issues with my tps the sensor is fine but for some reason on my aeroforce the tps is reading sporadic all the time and when off the gas in park it's reading like 3-5% and idling up like my foot is on gas but it's not. Changed tps with brand new one and still does it. Cleaned throttle body and throttle body blade as well from carbon build up. When I unplug tps it reads 0% but still idles high. When I take tps off tb and plug in tps it reads 0% and scales up correct but when I install back to tb it reads 3-5% and goes very sporadic when driving as well. im on a stock l36 tb as well. if i unscrew the tps sensor i can roll the sensor in the tb to read zero but then cant fasten it down as the bolt holes dont line up. that i know of there is no way of calibrating these either.

Both old and new sensor is doing this though. When the tps is on tb and I press gas it reads correct 99% at wot not running and scaled good not running but holds open when should be closed. When started and driving it bounces all over. say i am going at 15% throttle if will bounce up to 30ish% and then 0% and all over while not moving my foot off the gas.


My fuel gauge has been on a fritz as well it will read good then go full then empty etc. Changed sending unit and stepper motor and still does it. Also parking lights in the head lights don't work but head lights tail lights and turn signals work. I'm at a loss with that as well....

anyone have iny ideas on where my electrical gremlin is so i can kill him?!?!?!

 

Hi John, I'm not sure bit you may be having an issuewith your PCM. I say this because your issues are sporadic and the actual electronic part is new or tests good.
It could Also be a frayed wire or a bad board in the instrument cluster. But I'm going with the PCM because it is affecting performance. Look for What's common to all your symptoms and I will bet That's where the problem is!

 

Good call jc. I am almost positive it's a pcm issue as well at this point. My aeroforce has codes stored for map low voltage tps low voltage and fuel level low voltage. These are all a 0-5volt reference and come from different pinout on the pcm so not the same wire.

I have a spare pcm so when I get free time I will install spare pcm burn the tune and do case learn and security learn and see if it fixes it!!

 

John:
Heres my 2 cents...
You probably already checked this but I'm going to say it anyway...

I don't believe its a TPS issue....
I think its more along the lines of a fuel pressure issue... Have you checked the fuel pressure at the fuel rail? Maybe... Its showing signs of a clogged fuel filter or possibly even a failing fuel pump? Dirty clogged/failing injectors..

2nd
Maybe...You actually have a vacuum leak somewhere? They cause reek havoc on these motors and make things hard to do a diagnostic determination....

Sometimes its the simplest of things that throw us off.
As far as your DRL's...
Maybe its a ground issue.. dirty rusty connection and or a fuse isn't making good contact if it isn't blown?....

Or it could have something to do with the multifunction switch/control.. But that's a reach at best. I mean it is 10 yrs old... things are going to get worn out corroted etc...

Hope this helps!
I'm sure others will chime in with other ideas/fixes..

 

Good luck John. These sporadic issues are hard to pin down. It's bad that multiple systems are affected but in a way That's good cause there is a common denominator.
Hope Turbo Monte is feeling better soon!

 

No vacuum leaks and great fuel pressure. The map tps and fuel level sensor are all a problem and all tied into a 5 volt reference. If one sensor goes down they all go down. I'm thinking either map sensor or wiring or pcm at this point

 

If you replace your MAP then do your PCV Valve while your there. It sits right under the map. At least on the 3800 it does!

 

Pcv is deleted and I'm running a catch can off front valve cover do to turbo stuff lol

 

Shows how much I know. I still think it's your PCM

 

Hello John, I sent Matt your question and this is his reply. Hope it may help...

On your friends car I would check the 5 volt ref for stability and the ground system, sounds like a ground problem, all the grounds for the TPS and the fuel tank sender go to the PCM, the PCM grounds in the transaxle stud near the starter.

Matt Snell
Paul's Automotive and 4x4 inc.
48 E 9400 S
Sandy, Ut. 84070
801-255-7472