the fans on this car won't turn on until 240 deg. then go off at 220. how do i get the fans to kick on much sooner and stay on.
thanks,
kevin.

 

I Would Buy A New Fan Switch From Hypertech. It Turns On The Fans On At A Lower @ 200* and Off @ 185*. You Can Order One From Jegs Or A Summit Catalog For $42.99 . The Switch Is Located On The Passenger Side Head Between #6 And #8 Spark Plugs. Good Luck.

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88' IROC-Z, 350 TPI, 700-R4

 

kevin,

It sounds like the ECM is doing its job. The fans turn on and off with coolant temperature changes. The problem is that the ON temperature should be more like 223°F for the primary fan. It's possible that the CTS that reports to the ECM is not calibrated correctly and/or the CTS that reports to the dash instrument is not calibrated correctly. The dash gauges are notoriously innaccurate. If the dash gauge is incorrect the CTS for the ECM nmay have poor connections and/or be out os spec.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

The Connection on my Switch broke. All that is left is a piece of wire. The plastic part that secures the switch broke off in pieces.

How can I fix it.Right now I have jamed the wire into the switch.Sometimes it goes above 220.

Please help me. I have a '89 305 TBI bird.Can you tell which one is the best? I can goto Autozone and get one,but I don't want something that sucks. I want a switch that will make me and my bird cool.
THANKS!!

 

Hey Manuel.

Sounds like you have a similar problem as we did a while back.

Did yours break or did it fry?
By fry I mean litterally go into melt down mode?

Ours cooked like you would not believe. The plastic got so hot that it melted and when you touched it it would cumble in your hands. So hot that it burnt the wire in two. It also took along a fuseable link that is in between the radiator and battery.

Anyone ever run into this type of problem?

I know or at least think I know why it happened.
The electric fan motor had bad bearings and eventually stopped working. By the time we figured out what happened the fanswitch and fuseable link fried.

Replaced the fan motor and the fanswitch but now the fan only comes on while the ac is on.
This all happened before I found this group and so I had to take it to pep boys for repairs.
It took them a half a day to figure it out and it still don't work right.

I know about the sensors and the relays.
But I can only find the sensor that is located right next to the T-stat on the intake manifold. I've heard there are two other sensors on each head but I can't locate those.

And I'll let you guys in on a little tip that I found out the hard way.

I read in another post regarding these sensors. Someone said that on a v6 you can unplug the intake sensor to see if the fan will come on.
So I go out and unplug it and try to start the car. I smell huge amounts of gas and the car won't start.
Well, I figure that this thing is hooked up to the computer and is not the right sensor for the fan.
So, I plug it back up and try to start the car again. This time the same thing happened. I smell huge amounts of gas and the car won't start.

Ok, so now I'm freekin out because this is our daily driver and the only car we have!!!

I sit down and smoke a stogy while I'm scratching my head.

Then I remembered if I unplug the battery that it should reset the computer. So I get ready to do that and I decide to try and start the car one more time. I hit the key and Vroomm vrooomm!!
I was SO Happy that it started.

So if you guys unplug that sensor that's located right next to the T-stat on the intake. Expect you car not to start!
After you plug it back in wait a few minutes for the computer to adjust and it will fire back up.
You might have to put the key in the ignition and turn in order for the computer to adjust. I think i've heard that on here before.

P.S All this is on a stock 305 TBI
What a learning experience!!

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91 Mystic Teal RS Convertible (1 of 5,000+ made in '91)
Stock 305 TBI W/125,000 miles
Auto Trans, Stock Rear End
Stereo
Nakamichi CD-35z, Infinity Kappa Series 4x6 & 5 1/4" speakers, Fosgate 12" sub in a custom box, 200watt amp for the sub.
Future Mods & Add Ons

• Infinity Basslink
• Hooker Headers
• 3" Exhaust using Flowmaster 80 series muffler
• MSD Ignition
• K&N Filter
• Some Suspension Improvements

Dream Machine
Same car full blown with a 9" rear end and all the needed mods to help keep it on the pavement.
(aka) Something I'll never have!!
[*][*]

 

ahhh, yes the two T-Stats in the head, ok, look between Cyls 1 and 3 and 6 and 8. You will see them, they are there (at least on my 1987 IROC TPI). they are about 20.00 each.