We used teflon tape to put the coolant sensors (fan switch, gauge, computer's CTS, cold start injector switch)- did we just eliminate the ground on some of these? I think the cold start injector switch & computer's CTS would still work, but what about the sensors with one wire going to 'em?

Thanks!!


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

Tom,

It might not be as bad as you think. Most ECM sensors are not referenced to engine or chassis ground, but have a separate ECM ground wire routed to the sensor. The CTS, MAT/IAT, auxilliary oil pressure sensor (for the fuel pump), and detonation sensor will all work without an engine ground.

The auxilliary fan switch (if you have dual electric fans or TBI), temperature sensor for the gauge, and oil pressure gauge sensor may require a good engine ground, but you still might be grounded if the sensor threads have cut through the PTFE tape.

There is a pretty good chance that everything will work correctly, since the tape will get displaced as the threads a tightened. If you are concerned, you can check resistance between the individual sensor bodies and the engine case as a ground reference. Any sensors with more than a couple ohms resistance may require tightening or a different sealer.

Good luck - we're waiting to hear it run....

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Later,
Vader
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"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

 

I just did an engine swap in my car and I have the same question. My temp gauge sensor (one wire on drivers side head) is all fubar. I don't know what's wrong with it but sometimes it'll display the correct temp, sometimes it'll show overheating and just climb visably but realistically as if a hose busted. I can't figure it out. I'm going to test the sensors chassis ground because we used teflon tape for all sensors and plugs. It scares me when I'm driving and all of a sudden the temp says the engine is overheating, I pull over and pop the hood but the overfill is low and no boiling sounds. It's starting to **** me off. Almost as much as when CarParts gave me a TPI IAT sensor which looks EXACTLY the same as the TBI CTS.

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, Jon (350 TBI!)
91 Red RS w/grey int, sq stereo (Alpine v12, kicker solo, MB quart premium etc)

• Holley 670 TB unit w/ 1/2" spacer/adapter
• Edelbrock RPM vortec intake
• 350ho 330hp vortec crate motor
• 8" harm. balancer
• Stewart stage 2 water pump w/160 thermo
• SLP tri-y headers to full 3"
• Rebuilt trans w/ SLP shift kit
• Centerline 16x8's all around
• 36/24 mm sway bars
• Full poly bushings, even motor mounts
• SLP LCA and panhard
• Alston SFCs
• Edelbrock 3 point STB
• Global west steering brace aka wonderbar
• Eibach pro kit springs
• Bilstien high perf. struts and shocks
• All this and I still have AC

My websiteAny questions?

 

Thanks for the info, Vader! I'll have to check those out today. Looks like the last few hours of working on this 2.8 happen today!


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!