malo68

I've been dealing with an electronics issue which is causing the car not to start. I am not getting power to the fuel pump BUT the pump, ECM, oil pressure switch, and fuel pump relay are good and doing what they should. I am not getting power at the either side of the fuel pump fuse labeled "F.P." on the fuse panel. What about this though....When I jump the left side of the under dash fuse holder with 12v, I get power all the way back to the pump. So that tells me that something is not providing power to the fuse panel...but what and why not? Note: the ALDL socket under ashtray is working and as is the check engine light. I've had this car over a week but haven't been able to get it to run yet. I'm hoping to have an "Yes! I've got it!" moment...but right now, the arms down, the lights are flash in', but there ain't no train com in'. Lol. Please help get this baby running! Thanks in advance, you guys rock.

briankeery

Can you pull the fuel pump fuse and check for corrosion on the "input" side of the fuse block - you should have 12v there. If not, we may need to pull off the fuse block to see what's going on behind it. There are documented cases here on the forum where guys have had bad connections on the back of their fuse blocks. Good luck.

malo68

Well, made a little headway today. The fuel pump is now energizing for 2 secs. with key on bzzzzzt. and when I crank it over, I'm getting fuel to the throttle bodies. I installed a pressure gauge between the 2 throttle bodies and am getting 12psi when cranking. However nothing is spraying out of the injectors. I tested the injectors manually by jumping the oil pressure switch to make the pump run constantly. I then got a lantern battery and tapped the injector leads, as it made contact, the gas sprayed out. So the injectors seem to be working so why am I not getting power to them? Could it be the HEI module? Something else? Thinking I should I just break down and buy a shop manual...

74 LS4-454

I am not the best at electrical, and I'm sure other members will give their thoughts.....
Did you check the two 3 amp fuses for the injectors in the fuse panel?
If I remember correctly, they are at the bottom of the panel.
Be sure to check out the "sticky" in the above section....and yes get a Shop Manual.......

malo68

Yes, both 3A fuses are good and I've also read the sticky (great info) but no luck. I hooked up a noid light to the injector wires and found that they didn't pulse with key in run position or cranking. I then checked fuel pressure with a gauge I installed between the TBs and found that it's not holding fuel pressure for more than a few seconds. Would the fact that it doesn't hold pressure keep the injectors from pulsing upon startup? Not sure where to go from here. Need to find out why the injectors are not holding pressure. Any ideas??

malo68

Got it running!!! Seems that even though the injector fuses showed good on the test light they weren't working. I took out the fuses, ran sandpaper over them and put them back. All of a sudden the right injector started working. I the wiggled the fuse for the left while it was running and that started working. The contacts in the fuse panel were corroded enough to keep it from working...little bugger had me going craaaazy. Thanks for the replies!

74 LS4-454

Great news.....I would still change out those fuses, they are inexpensive enough, or make sure you carry some spares with you.....I would also check out the entire fuse panel for additional corrosion and make your repairs as necessary.
Enjoy your 82, when they are running correctly, they are alot of fun to drive........ Tom