Skip to main content
Topic: '84 302 CFI - no fuel pumps, injectors not firing (Read 4170 times) previous topic - next topic

'84 302 CFI - no fuel pumps, injectors not firing

Reply #15
Quote from: softtouch;303584
+1 for what ChuckW says.
The ECU has to power-up so it can provide the ground for the fuel pump relay and operate the injectors.

There is a small pig-tail wire on the negative battery cable. This is the ground for the ECU computer. Make sure it is connected.

The ignition switch picks the ECU power relay. This relay is behind the dash a little to the right of center. The relay has a 5 second delay on its' drop out. When you turn the key off, listen and see if you can hear it drop out 5 seconds after you turn the key off.


Subscribing.  You all have me interested now. Im all about learning new stuff.
41 Dodge Luxury Liner Sedan
78 F-100 2wd flareside
84Turbo Coupe
84 Thunderbird Élan
85 Thunderbird 3.8
88 Turbo Coupe
88 Mustang GT
90 Stang LX 5.0 5spd
93 F-150 4x4 ext cab
96 Mustang GT
98 Mustang GT
99 SVT Cobra
06 Fusion SEL
14 Fusion Sport

'84 302 CFI - no fuel pumps, injectors not firing

Reply #16
Quote from: softtouch;303584


The ignition switch picks the ECU power relay. This relay is behind the dash a little to the right of center. The relay has a 5 second delay on its' drop out. When you turn the key off, listen and see if you can hear it drop out 5 seconds after you turn the key off.


On mine the ECU relay has been above the ECU on the pass side, WAAAY up under the dash.  Has been on both my 83's and 84's.
Long live the 4-eyes!  - '83 Tbird Turbo

'84 302 CFI - no fuel pumps, injectors not firing

Reply #17
I can't tell you how much I appreciate all your suggestions guys.  Unfortunately I'm not going to be able to get to this car again until Christmas day so I won't have an update until then.  Sorry to keep you in suspense.  To keep you entertained, here's a picture of the car.  I'm sure some of you remember it.  The engine is now PURPLE[/color].  BLEH.  But that's what my sister wanted, so that's what she got.

.
1984 Thunderbird V8


'84 302 CFI - no fuel pumps, injectors not firing

Reply #18
UPDATE

The car is running now, no problem.  I want to thank you all for your advice and suggestions.

The winner-
Quote from: softtouch;303584
+1 for what ChuckW says.
The ECU has to power-up so it can provide the ground for the fuel pump relay and operate the injectors.

There is a small pig-tail wire on the negative battery cable. This is the ground for the ECU computer. Make sure it is connected.


The "small pig-tail wire on the negative battery cable" was never disconnected, but somehow the connector itself had gotten so corroded that it was no longer a functional ground for the ECU.  I opened the connector, saw how nasty it was, then cleaned and reconnected it and it fired up on the first turn of the crankshaft. 

Amazing how the simple things can bring a project to a halt. 

Again, I wanted to thank you guys for your help.  Hope you all had a great Christmas and have a Happy New Year-
Danny
.
1984 Thunderbird V8


'84 302 CFI - no fuel pumps, injectors not firing

Reply #19
I was gonna say that!  I had an issue with the car bucking and stalling.  Felt like it was the transmission acting up so I'd pull over and start it back up it would run fine.  It was the ground on the battery cable that was loose which caused it to shut off.  I was gonna suggest that ground also.
84 TC 302 -5.0L/t5/7.5 locking rear and a 3.45 gear, Edelbrock Intake, Aluminum Heads, Edlebrock 65mm Throttlebody, Edlebrock Cam, 24lb injectors & MAS Air Sensor calibrated via chip,  BBK headers, Catback H pipe, Magnaflow lers :evilgrin:
:pics-stfu:

 Project Thread with pics