Last week I swapped out the original working single fan and installed a LT1 shroud with fans. The passenger fan works just like the original fan--ECM controlled factory temp setting with A/C activation. The Driver fan is setup to run with a temp switch that is supposed to be in the block.

Problem:
The plug in the block between #6 & #8 cylinders. 1/4 and 3/8th didn't fit so I tracked down a Snap-On guy and bought a 5/16th square pipe socket to try and get it out. Needless to say, didn't work. It was as if the socket was still slightly small and wouldn't go quite all the way in. I traded the socket for an 11/32nd but have not been able to try yet.

Questions:
Is 11/32 the correct size for the plug or is there a "special" socket for this?
Is there a good in-line groundable hose adapter I use on the lower radiator hose if I can't get the plug out?

Many thanks!

 

This is a pic of the intake base. The CTS for your ECM is coming out of the front under the bypass hose, If you look just to the left you will see a plugged off fitting. That goes to the water jacket inside the manifold, see if you can use that plug for your sensor for the fans.

 

Vinny , If I understand your post correctly , the plug you refer to is the Cold Start Injector switch .

If the OP has his cold start injector deleted (with the appropriate ECM reprogramming) he'll have no problem eliminating the CSI switch , but if the CSI is still functional he will likely have cold start issues (long cranking times) without that switch in place ....

 

Do you have a picture of the plug?

 

Yes Orangebird that is correct. I just did not know what the original sensor was for. I have a 91 so I don't have one of those. The OP probably is using it as he says he has an all original TPI See you do learn something everyday!

 

Here is it! Looks like there another indent 45* to the initial socket?




Everything is still in place on my car so that spot you are referencing vinny R is probably occupied. Good idea though, sounds like it would give a very accurate reading.

On a related note, shot the intake above the thermostat yesterday. Discovered the thermostat is stuck shut! The temp gauge in the cluster appears accurate enough. Was reading ~200* when the gauge was at ~220* with the thermostat closed.

 

That's what I was thinking it may be. I've always used a ratchet an extension to remove them. And no need to go all the way down in there, that's just extra metal from forming the square opening part. Also, if you do have the "correct" tool for removal and its a bit loose, put some valve grinding compound on the tools flats to help get more grip.

 

That's good to hear. Hopefully the 11/32 socket I have will fit it now, going to try one more time this upcoming weekend. Will try tightening it a tiny bit to break it loose before attempting to back it out.

Would an inline adapter on the lower radiator hose be a good secondary location? I already have a Standard TS-136 temperature switch which I believe is a 3/8th diameter. Has BWD TFS8 on label as well; seems to be the same as several other switches (https://www.partstech.com/Standard-I...4312&store=691).

 

if you cant find anything to fit i use the end of an extension and if that doesnt fit i usually grind down the sides of the extenstion till it does lol that ALWAYS works good luck

 

Heat it up before trying to turn it.

Heat it, then put some penetrating oil around it.

Or as I had to, drill it and use a tap remover

 

To be on the safe side I'm letting a mechanic take a look at it. The Original thermostat is needing replacement and I can't get the bolts off there either. Thermostat is stuck closed mostly so that takes priority at the moment. Told him if it looks doable to try getting the plug out. I'll be praying for Christmas magic that both will be easy for him.

 

News update. Mechanic put in the new thermostat and cleaned the throttle body (bc the bolt broke and had to be taken off). Car starts and idles better now after a bit of adjusting. Unfortunately he couldn't get to the plug so I told him not to worry about it. Going to abandon the idea of getting that plug out at this point and go another route.

It a bizarre twist, I had replaced the temp sensor for the ECM and sprayed cleaner on the corrosion on the connector. Now the computer controlled fan comes on only after a couple minutes and just runs until the car cuts off. So the temp only goes between the 1/4 and 3/8 area of the gauge and no hotter. Also replaced the gauge temp sensor and it reads exactly like the old one so fairly certain it's accurate after shoot infrared thermometer on the t-stat housing.

I'm looking at in-line t-junction on the heater core hose, in-line junction on the lower radiator hose, or the plug at the top of the water pump. Out of these options which would be the best for the fan switch?

 

Not the plug on top of the WP. That's the cold (already cooled) side of the system. Same for the lower hose.

Heater hose would be OK, as long as you put it on the hot side. I.e., the hose that connects to the top of the intake. NOT the one that goes into the WP or the cold radiator tank (also part of the cold side of the system).