Fan running constantly

Decipha's custom GUFX strategy covers all 89-93 foxbody ecu's including the 88 mass-air california ecus.
bad86capri
Posts: 44
Joined: 2021 Feb 16, 10:09
Location: Knoxville, TN
Vehicle Information: 1986 Capri 306, Twisted Wedge heads, RPM II Intake, Anderson B3 cam, 80Lbs Siemens Injectors, MAC Longtube Headers, G-Force T5, Spec 6 Puck Clutch, Ford Racing Aluminum Driveshaft.

Fan running constantly

Unread post by bad86capri »

Alright I've been fighting the nonstandard and misfire issue for awhile now. Today I changed the fuel pump thinking that was problem, didn't fix it. I changed the distributor and module, that didn't do anything. I swapped the coil thinking it could be going bad, nothing. Luckily all these parts that I swapped were with parts good known parts I already had so no money was spent. What I've discovered during all of this is the car will not even attempt to fire. When you turn on the key the electric fan, which is wired into the factory harness and I'm using the QH to control, runs constantly. It'll run then act like it loses power for a split second then. Like it's cutting in and out. I'm lost at the moment and need a little direction on this. I'm not sure if I have a wiring issue or a tune issue. Anybody have any ideas?

And the fuel pump runs constantly.
decipha
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Re: Fan running constantly

Unread post by decipha »

pump runs constantly then the j3 port isnt communicating
dleach1407
Posts: 362
Joined: 2021 Mar 21, 15:17
Location: Colorado Springs, CO
Vehicle Information: 95 Mustang GT, CBAZA Quarterhorse
331, 190 11R heads, Edelbrock Victor 50 manifold, F303, T5, 76mm Turbo, 91 octane, Returnless dual pump 03 cobra tank, Behind bars rails, 80# siemens injectors

57 F100, RZASA, 04 Crown Vic ecu and harness, 302, GT40 heads, 4r70w, 80# deka5 shorties, Holley carb style throttle body, Speedmaster high rise intake manifold

Re: Fan running constantly

Unread post by dleach1407 »

The only time I've ever run into a constant pump running was me corrupting my tune. Is your battery dead on your quarterhorse?
bad86capri
Posts: 44
Joined: 2021 Feb 16, 10:09
Location: Knoxville, TN
Vehicle Information: 1986 Capri 306, Twisted Wedge heads, RPM II Intake, Anderson B3 cam, 80Lbs Siemens Injectors, MAC Longtube Headers, G-Force T5, Spec 6 Puck Clutch, Ford Racing Aluminum Driveshaft.

Re: Fan running constantly

Unread post by bad86capri »

I put a new battery in it today and done the same thing. I guess there's a chance that the new battery I installed is dead or low. I'll pick up another battery and try it. I'll also build a new tune in case my tune is corrupt.
dleach1407
Posts: 362
Joined: 2021 Mar 21, 15:17
Location: Colorado Springs, CO
Vehicle Information: 95 Mustang GT, CBAZA Quarterhorse
331, 190 11R heads, Edelbrock Victor 50 manifold, F303, T5, 76mm Turbo, 91 octane, Returnless dual pump 03 cobra tank, Behind bars rails, 80# siemens injectors

57 F100, RZASA, 04 Crown Vic ecu and harness, 302, GT40 heads, 4r70w, 80# deka5 shorties, Holley carb style throttle body, Speedmaster high rise intake manifold

Re: Fan running constantly

Unread post by dleach1407 »

If the battery was bad, it corrupted the tune so you world need to reload it after replacing the battery.
dleach1407
Posts: 362
Joined: 2021 Mar 21, 15:17
Location: Colorado Springs, CO
Vehicle Information: 95 Mustang GT, CBAZA Quarterhorse
331, 190 11R heads, Edelbrock Victor 50 manifold, F303, T5, 76mm Turbo, 91 octane, Returnless dual pump 03 cobra tank, Behind bars rails, 80# siemens injectors

57 F100, RZASA, 04 Crown Vic ecu and harness, 302, GT40 heads, 4r70w, 80# deka5 shorties, Holley carb style throttle body, Speedmaster high rise intake manifold

Re: Fan running constantly

Unread post by dleach1407 »

Also wouldn't be a bad idea to clean the j3 connector on the board with a ScotchBrite pad
Trogdor
Posts: 8
Joined: 2021 Feb 21, 15:51
Location: Anna, TX
Vehicle Information: 1993 Mustang 5.0 LX
- B cam
- 76mm C&L with tube for 24 lb injectors
- Old type Ford Motorsport 24 lb injectors
- In fender CAI
- Catted X-pipe
- 2 chamber flows
- 3.73:1 gears
- T5
- T4M0 computer (originally an auto car converted to 5 speed with A9P computer)
- All else is stock

Re: Fan running constantly

Unread post by Trogdor »

I had an issue with the fuel pump in my car running constantly and the car not wanting to start. Turned out to be the caps in the computer were due for a replacement. Once changed the car fired right up.
Kingranch
Posts: 26
Joined: 2021 Jul 22, 01:51
Location: Austin Texas USA
Vehicle Information: 1990 mustang GT tko 500
Stock bore 302 block
moroso 7qt pan
E303 cam
Afr 165 heads 1.6 rocker arms
Holley systemax intake
42# Bosch injectors
Accufab 75mm tb
80mm pro M maf/ 42# calibration
Vortech SC upgraded to si trim
Anderson power pipe
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Egr spacer/delete
unequal stainless Headers
X pipe Mac mufflers/flowmaster tails
340 aeromotive fuel pump/fpr
8an 6an lines
Trickflow fuel rails
autolite 23 plugs
wbn2_aemuego

Re: Fan running constantly

Unread post by Kingranch »

id suggest the caps also-
another thing when that QH battery is removed it wipes the memory so the tune is gone I would bet
bad86capri
Posts: 44
Joined: 2021 Feb 16, 10:09
Location: Knoxville, TN
Vehicle Information: 1986 Capri 306, Twisted Wedge heads, RPM II Intake, Anderson B3 cam, 80Lbs Siemens Injectors, MAC Longtube Headers, G-Force T5, Spec 6 Puck Clutch, Ford Racing Aluminum Driveshaft.

Re: Fan running constantly

Unread post by bad86capri »

I think I have several things going at once here. The first being the capacitors going bad, which is funny because i actually replace these as a side gig but havent done my own. The second I think the battery couldve been going bad on the QH, not a 100% sure though. The third is my factory wiring harness has some of the tabs the that keep the pins from pulling out of the 60 pin connector are broke, which allows some of the pins to work themselves out. So when i get time im going address all the issues above.
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