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sensor ground issue

Joined
Oct 26, 2010
Messages
13
Location
East peoria, IL
I'm having an issue with my sensor ground. The car is throwing 5 CELs; baro, iat, tps, cts, and knock. The knock sensor plug was ripped off at some point during my head swap, just haven't replaced it yet.

Some background for you... I got the car about a year ago, and shortly after did timing on it. Unfortunately I did not put locktite on one of the bearings /ubbthreads/images/graemlins/banghead.gif and bent over half my valves. The new head has behives and 272s and I used arp studs. I put everything back together and started her up, she ran for about 30 seconds then smoke came up from the ecu. I wish I had pictures of it but I didn't think to take any. It was textbook blown cap, to the point where there was no board separating the pos and neg of the cap. After the ecu went I tried two more and that's where I'm currently at. Both ecu's are fine, they display the same codes every time.

I have checked: both ecus (continuity between pins 17 and 24), sensor voltages, sensors, and continuity between the sensors themselves and the ecu.

No sensor grounds if the ecu is unplugged and with the ecu plugged in they all ground.

To put it lightly, I'm lost, at this point I have no idea what to check. I hope its something simple and stupid that I forgot.

Thanks for all the help.
 

ktmrider

Well-known member
Joined
Sep 10, 2007
Messages
3,128
Location
Tempe, AZ
There are two Body to Chassis grounds on the IM ( one by the throttle cable mount, one below that ). Both goto the firewall by the CMC.

Assuming you "ripped out" the connector to the KS did you do the same to the two ground wires?!?
 
Joined
Oct 26, 2010
Messages
13
Location
East peoria, IL
Just to clarify... the KS was unplugged and the connector (KS end) got stuck on something and came off when I took the head off. I did not just rip the head off with things connected. /ubbthreads/images/graemlins/rofl.gif
 

iceman69510

Turn Right Racing
Staff member
Joined
Mar 5, 2001
Messages
10,968
Location
Michigan
Baro and IAT come from your air flow sensor.

Coolant temp can be from a bad sensor, or wiring (usually very brittle in this area) or even a low level.
 
Joined
Oct 26, 2010
Messages
13
Location
East peoria, IL
I have tested another known working MAS and the ECU still throws the codes. Also tested both IAT sensors out of the car and they are giving correct resistance for room temp.

Although the wiring around the thermostat housing is brittle I don't think its my problem. The G/B wire from the CTS has continuity back to the ECU and the other sensors (like stated in my original post).
 
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