C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Hot or not? 84 CFI

Thread Tools
 
Search this Thread
 
Old Mar 7, 2014 | 01:43 PM
  #1  
Carabajal87108's Avatar
Carabajal87108
Thread Starter
Intermediate
 
Joined: Mar 2014
Posts: 32
Likes: 0
Default Hot or not? 84 CFI

Ok gentlemen, I am back at it and now have the car started that is by putting a direct wire from battery to orange wire on fuel pump relay. so now the green wire shows 12vs and the 2 reds show 12vs. I tried a simple test that works on other chevy's but got different results. I disconnected the ground from battery and every wire including grounds are hot, meaning they have .002-.004 volts going through them. even the ground on intake has voltage of some sort. Reconnecting ground to battery everything is showing up as a ground, using a ground/positive finder. Has a point with two alligator clips you connect to battery that flashes green for ground or red for positive.

On another note what colored wires is the fan relay suppose to have? Also which is constant and whichat are the functions of the other wires. when I jump a green wire with the battery fan comes on with key being on.

when inspecting wiring harness on Driver's side that goes towards frond end there are 4 brown wires connected to one is that the way it was done in factory, for CFI's?
Reply
Old Mar 7, 2014 | 02:01 PM
  #2  
Carabajal87108's Avatar
Carabajal87108
Thread Starter
Intermediate
 
Joined: Mar 2014
Posts: 32
Likes: 0
Default

This is after replacing oil sender, fuelrelay, fanrelay, ecm, ground and ground connectors on backside of dside head, evrthing else is getting power, as in lights, distributer, and interior lights and gages. Just no readings from map sensor, either relay or, oil sender for power. Oil unit is showing reading on gage, around 30-50psi. The wire colors from fan relay are green/white stripe, Black/orange stipe, fat red, and blue that is from harness the wires in the clip are different, two for sure are brown/w stripe connected to blue, green white connected to orange. When I put 12vs to blue wire on fan relay the relay under blower motor kicks, blower doesn't turn on. Also I found out of the 5 grounds on back of head, one wire was orange? NEED HELP PLEASE,about to have a toggle switch board for mean time.
Reply
Old Mar 7, 2014 | 02:48 PM
  #3  
74 LS4-454's Avatar
74 LS4-454
Melting Slicks
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2006
Posts: 2,248
Likes: 67
From: Warrington PA
Finalist 2020 C4 of the Year - Unmodified
Default

Glad you are running, at least you know it still works.....
I'm sure one of the electrical experts will offer some answers and (or) suggestions to your questions. I can look in the 82 shop Manual this weekend, but don't know if that will help you out, as again there may be wiring differences between the 2 years. Keep at it........Tom
Reply
Old Mar 7, 2014 | 03:53 PM
  #4  
1977L48's Avatar
1977L48
Pro
 
Joined: Sep 2012
Posts: 600
Likes: 6
From: Key West Florida
Default

all i know is on my stepfathers 84 we got fed up with the factory switch and just put an aftermarket thermal switch wired to fan and have it grounding when it gets hot to turn on the fan.
Reply
Old Mar 7, 2014 | 04:17 PM
  #5  
Easy Mike's Avatar
Easy Mike
Team Owner
Supporting Lifetime
20 Year Member
 
Joined: Jun 2000
Posts: 38,923
Likes: 1,482
From: Southbound
Cruise-In II Veteran
Default

I'm lost. If you have an 84, you should post in C4. Are you saying you have an 84 CFI system installed in a C3? Could 84 in the title line be a typo for 82?
Reply
Old Mar 7, 2014 | 05:31 PM
  #6  
Carabajal87108's Avatar
Carabajal87108
Thread Starter
Intermediate
 
Joined: Mar 2014
Posts: 32
Likes: 0
Default

What thermal switch are you refering to and how or what do I need to put one on, what did you use on your step fathers? 84 CFI is correct in 84 they still made a crossfire, 85 is when they came out with TPI-tune port injection. The body style is C4, but wiring and operation is still C3.
Reply
Old Mar 7, 2014 | 05:39 PM
  #7  
Carabajal87108's Avatar
Carabajal87108
Thread Starter
Intermediate
 
Joined: Mar 2014
Posts: 32
Likes: 0
Default Hot or Not?

Originally Posted by SSROADSTER
Glad you are running, at least you know it still works.....
I'm sure one of the electrical experts will offer some answers and (or) suggestions to your questions. I can look in the 82 shop Manual this weekend, but don't know if that will help you out, as again there may be wiring differences between the 2 years. Keep at it........Tom
Yes, made my morning this morning. On plus side, now the ECM is being seen on gage console. Meaning the check engine light will appear when key is on run but not started and will disappear when car is started. Also Injectors are pulsing like they should, no more steady flow. I'm thinking maybe to put hot wire to temp. control(location front of intake near therm stat.) only becuase when looking at wire diagram that is one of the switches that control it. What color wire is knock sensor?
Reply
Old Mar 7, 2014 | 08:53 PM
  #8  
74 LS4-454's Avatar
74 LS4-454
Melting Slicks
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2006
Posts: 2,248
Likes: 67
From: Warrington PA
Finalist 2020 C4 of the Year - Unmodified
Default

Originally Posted by Easy Mike
I'm lost. If you have an 84, you should post in C4. Are you saying you have an 84 CFI system installed in a C3? Could 84 in the title line be a typo for 82?
Don't be lost.....The OP has posted in the C4 section, I suggested to the OP to post here from previous threads for additional info on our forum, especially the CFI info we have got together over the previous year....Us CFI owners like to "stick" together. Every little bit of info helps!!! Tom
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old Mar 7, 2014 | 08:57 PM
  #9  
74 LS4-454's Avatar
74 LS4-454
Melting Slicks
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2006
Posts: 2,248
Likes: 67
From: Warrington PA
Finalist 2020 C4 of the Year - Unmodified
Default

Originally Posted by Carabajal87108
Yes, made my morning this morning. On plus side, now the ECM is being seen on gage console. Meaning the check engine light will appear when key is on run but not started and will disappear when car is started. Also Injectors are pulsing like they should, no more steady flow. I'm thinking maybe to put hot wire to temp. control(location front of intake near therm stat.) only becuase when looking at wire diagram that is one of the switches that control it. What color wire is knock sensor?
Sounds like you are making good progress, wish I had more time to help you check out answers for your questions, but off to work soon.....
Maybe this weekend can look into items further when I have time and if you don't figure it out sooner..... I'll add this thread to the "sticky" also, it will be another good reference in the future for us CFI owners...
Good luck and keep us posted as usual........ Tom
Reply
Old Mar 8, 2014 | 09:45 AM
  #10  
Easy Mike's Avatar
Easy Mike
Team Owner
Supporting Lifetime
20 Year Member
 
Joined: Jun 2000
Posts: 38,923
Likes: 1,482
From: Southbound
Cruise-In II Veteran
Default

Originally Posted by SSROADSTER
...Don't be lost...The OP has posted in the C4 section, I suggested to the OP to post here...
Thank you for the clarification.
Reply
Old Mar 9, 2014 | 11:25 AM
  #11  
1977L48's Avatar
1977L48
Pro
 
Joined: Sep 2012
Posts: 600
Likes: 6
From: Key West Florida
Default

it was just one off the shelf at advance auto parts, then cut the 2 wires that ran to the fan, sent one directly to the battery and ran the ground through the switch, it is adjustable so you can make the fan come on whenever you want.
Reply
Old Mar 9, 2014 | 03:14 PM
  #12  
Carabajal87108's Avatar
Carabajal87108
Thread Starter
Intermediate
 
Joined: Mar 2014
Posts: 32
Likes: 0
Default Re:

Originally Posted by 1977L48
it was just one off the shelf at advance auto parts, then cut the 2 wires that ran to the fan, sent one directly to the battery and ran the ground through the switch, it is adjustable so you can make the fan come on whenever you want.
I was looking into that, the set up I looked at has you place a temp probe in the upper radiator hose and tap into ignition, ground, and hot.
Something about a wire in the cooling system has me unsettled, incase it breaks and falls into water pump or gets stuck in motors, or intakes water jackets.

I also looked at a set of 2 after market 10inch fans, but wasn't sure if I could use them. hey come with there own shroud and mounting is right up against radiator with zip ties. I did some pondering and just a thought. If I used this dual fan set up , maybe just to be on safe side. Use a fan shroud off a 91 vette, becuase it has on off set mounting for what looks like a 10inch fan units. When comparing 3core alluminium radiators, the size for both 84 an 91 are the same. Any suggestions on this from anyone? I hear cooler is better, in New Mexico it gets pretty hot in summer.

One more thing has anyone out there ever used a switch panel in their car, I mean hooking up main feeds to panel for theft and control purposes. Fan, Fuel pump Relay, ECM, and other ma to panel.
Reply

Get notified of new replies

To Hot or not? 84 CFI





All times are GMT -4. The time now is 06:27 AM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE