Loopy idle

[Texvet]

Hey @Texvet any update?

I purchased and install an AC Delco coil and ICM. Runs like a top. No more cheap parts for this Hillbilly : )

 

[PlayingWithTBI]

I purchased and install an AC Delco coil and ICM. Runs like a top. No more cheap parts for this Hillbilly : )

Good to hear!

 

[tsr2185]

I purchased and install an AC Delco coil and ICM. Runs like a top. No more cheap parts for this Hillbilly : )

Same issue I got. Done did everything I can think of with playing's help. Got my ac 1984 icm coming in and I pray to god its fixes my crap idle. Im tired of dumping money into the engine and wanna fix up the interrior!

 

[1993GMCC2500SLX]

Interesting now you all have me wondering about O'Reilly's the ect I replaced by the thermostat is one of their parts because the one in the truck was corroded, and the ignition coil is a replacement from them as well,I couldn't get the truck to hardly run that however was before I found the oil pressure sensor fuel pump switch, and 4 spark plug wires that were about burnt in two?!

 

[PlayingWithTBI]

Interesting now you all have me wondering about O'Reilly's the ect I replaced by the thermostat is one of their parts because the one in the truck was corroded

You can easily confirm the CTS with a scan tool or check resistance at room temp, then warm up the engine and check it again. The ICM and coil, not so much. You can prove they're bad but, you can't prove they're good.

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[someotherguy]

Some can say I'm overthinking the subject but I am especially suspicious of CTS/ECT's, if they look old, I tend to replace rather than worry, and absolutely go ACDelco or Delphi. Never store brand or "me-too" brands. They're not expensive regardless, so go with the good name. All of them are import junk at this point but you hope for better QC with the big names.

Back to the overthinking - to really know whether a CTS is truly "good" you would need to measure its resistance over the entire normal range of coolant temperature. While the reading that *really* matters is when the engine is fully warmed up, you don't want it reading weird at any temperature. Generally though they seem to fail "cold" so if you walk out to a stone cold engine and say ambient temp is 60F and has held steady for several hours, you throw your ohmmeter on the CTS and it says somewhere around 5K ohms, it's *probably* good... if it says something like 20K, 30K then you really shouldn't be surprised when you try to start the truck and it's smoking black out of the tailpipe and trying to stall.

Richard

 

[1993GMCC2500SLX]

The sensor in the head doesn't look like it has ever been touched, and I bought the coil and the ect by the thermostat because there's a O'Reilly's near where my son goes to school and so that's where I went..

 

[someotherguy]

The sensor in the head doesn't look like it has ever been touched, and I bought the coil and the ect by the thermostat because there's a O'Reilly's near where my son goes to school and so that's where I went..

The one in the head is just for the dash gauge. One in the intake next to the thermostat housing is the one that contributes heavily to fuel mixture. Obviously they're both important, as you want to know if your engine is running too hot - but the other is the really important one in terms of how it is running.

Richard

 

[1993GMCC2500SLX]

Yes I just mentioned I haven't messed with the one in head til this truck runs well enough to see if it works or not I changed the one by the intake manifold thermostat housing because it was corroded and that is the feedback to the ecm

 

[1993GMCC2500SLX]

Yes I just mentioned I haven't messed with the one in head til this truck runs well enough to see if it works or not I changed the one by the intake manifold thermostat housing because it was corroded and that is the feedback to the ecm

So I don't know if the guage reads fairly close or not,I like the guages in this truck but I'll probably do the same thing as I did with the 86 Chevy k20 I traded for this truck it had a sunpro water temp 260' sweep mechanical 2 5/16 guage now I trusted. I didn't worry about having a brand new coolant temp sender in the head on that truck when I built the motor either because I already knew I was not using the factory guage.