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Jul 7, 2010 | 01:01 AM

#21

HlhnEast

Safety Car

Joined: Nov 2008

Posts: 4,328

Likes: 15

From: Jacksonville FL

Quote:

Originally Posted by MK 82

I need input for the following years from someone who has the applicable FSMs.

Need Temps and AC press and oil temp

for fan On and Off.

Also the fan configuration. Number of, placement, etc.

Please only chapter and verse from the FSM. No wags, please.

85, 87, 88, 89, 90, 92, 93

I have the 85 FSM in Al but am in FL. Will help out when I get back around the 16th. if no one else has.

Somewhere you need to post "if it aint pukin fluid, dont worry about it" Am I wrong about this? What temp does the cap blow at? Course I guess a cap could malfunction. I would worry in the 260 range but less than that, no. My Vette rarely rises above 200* fan doesnt kick til 220*

Jul 7, 2010 | 07:53 AM

#22

runner140*

Le Mans Master

Joined: Mar 2004

Posts: 8,700

Likes: 298

From: Ft. Lauderdale Fl

Eddie, I'm sure its there but didn't see "change radiator cap". A guess a little A.D.D.

Last edited by runner140*; Jul 7, 2010 at 07:53 AM. Reason: add

Jul 8, 2010 | 02:53 PM

#23

sailorsteve

Drifting

Joined: Jun 2010

Posts: 1,853

Likes: 8

From: Westerly RI

Quote:

Originally Posted by MK 82

Still need numbers gents. Help me create a single source document.

From the '92 FSM:

Primary Cooling Fan (Fan 1) [note: driver's side]

The primary cooling fan is controlled by the ECM based on inputs from the A/C system, Coolant Temperature Sensor (CTS), Engine Oil Temperature (EOT), Vehicle Speed Sensor (VSS), and rpm.
The ECM will turn the primary cooling fan "ON" when any of the following conditions exist at idle.

*Any ECM trouble code is set.
*CTS above 104C (219F).
*EOT above 132C (270F).
*A/C head pressure above 189 psi.

Once the primary fan has been turned "ON" by the CTS or EOT, the ECM will turn the fan "OFF" when that temperature has dropped about 5C (41F). If the primary cooling fan has been turned "ON" by high A/C head pressure, the ECM will turn the fan "OFF" when the pressure has dropped to 150 psi. The minimum "ON" time for the primary cooling fan is 50 seconds.

Secondary Cooling Fan

The secondary cooling fan is controlled by the ECM based on inputs from the A/C system, Coolant Temperature Sensor, Engine Oil Temperature (EOT), Vehicle Speed Sensor (VSS), and rpm.
The ECM will turn the secondary cooling fan "ON" when any of the following conditions exist at idle.

*Any ECM diagnostic trouble code.
*CTS above 108C (226F).
*EOT above 136C (277F).
*A/C head pressure above 225 psi.

Once the secondary fan has been turned "ON" by the CTS or EOT, the ECM will turn the fan "OFF" when that temperature has dropped about 5C (41F). If the secondary cooling fan has been turned "ON" by high A/C head pressure, the ECM will turn the fan "OFF" when the pressure has dropped to 189 psi. The minimum "ON" time for the secondary cooling fan is 26 seconds.

This is verbatim from the FSM, but for both fans, the temperature drop stated of 5C (41F) doesn't seem correct, because a drop of 5C would equal 9F and a drop of 41F is about 23C. Maybe the '93 manual was corrected.

Jul 8, 2010 | 05:21 PM

#24

toptechx6

Safety Car

Joined: Jun 2006

Posts: 3,629

Likes: 28

From: FL

Quote:

Originally Posted by sailorsteve

Looks like the 93 manual was corrected, mine reads the same as the above except that the Fahrenheit temp in parenthesis is (9*F) not (41F)
Note too that ECM inputs VSS and RPM are also mentioned as applicable to fan control, but I can find no mention of speed or RPM parameters used even after checking cooling, A/C and EFI sections of the manual.
That is where you may require input from the tuners.

Jul 8, 2010 | 07:39 PM

#25

toptechx6

Safety Car

Joined: Jun 2006

Posts: 3,629

Likes: 28

From: FL

Quote:

Originally Posted by MK 82

Thanks for the input. Jim, can you post the numbers for the 93?

Eddie

As mentioned above Eddie, all 93 numbers are identical to those posted by sailorsteve except for the Fahrenheit temp number in parenthesis. The 93 manual reads (9*F) not (41*F).

Jul 9, 2010 | 11:00 AM

#26

toptechx6

Safety Car

Joined: Jun 2006

Posts: 3,629

Likes: 28

From: FL

Quote:

Originally Posted by MK 82

Great. Do you have the oil temp related number. Should be 260ish. Wasn't sure if you meant they were all the same. Updated. Missing a lot of L98s. We have all the LT1s. I will make it look pretty once all the data is in.

Eddie

I'm pretty sure that is the number sailorsteve has listed as "EOT" = 270* for primary and 277* for secondary.

Jul 9, 2010 | 01:39 PM

#27

SuperL98

Drifting

Joined: Jun 2001

Posts: 1,704

Likes: 459

From: Mass Mass

MK82, I appreciate what your trying to do, I can help on the 1988

Data from the 1988 FSM and the ABTS chip (1988 Automatic Trans)

From the FSM:

The electric cooling fan on this engine is controlled by the ECM. The ECM will ground the cooling fan relay, which turns “ON” the fan, when the following conditions are met.
* Coolant temperature sensor signal indicating a temperature greater than 108 Deg C (226 Deg F)
* Or: A/C head pressure greater than 233 psi (1606 kPa)
* And vehicle speed less than 40 mph.
When the cooling fan is turned “ON”, the ECM will keep it on for a minimum time of 30 seconds.

From the FSM wiring diagram:

Auxiliary coolant fan temperature switch closed above 228 Deg F (109 Deg C)

From the ABTS Bin file:

Fan Off Coolant Temp Threshold (A/C On) 104.75 Deg C (220.55 Deg F)
Fan ON Coolant Temp Threshold (A/C On) 107.75 Deg C (225.95 Deg F)
Fan Off Coolant Temp Threshold (A/C Off) 104.75 Deg C (220.55 Deg F)
Fan ON Coolant Temp Threshold (A/C Off) 107.75 Deg C (225.95 Deg F)