Hello all, first off I have solved 95% of my problems with my new to me 83 280zx by the search button on this fourm but I can not find anything on this one. So when I turn the key on 7 out of 10 times the fuel pump relay will start clicking really fast and all I have to do is kick the ecu and it will stop. Every now and then it will do it driving, and start jearking real bad till I give the ecu a kick and bam its back to good. I have cleaned every plug on the car more then once, checked wires from main plug to ecu and no change. It will not do it if you move the plug around while its running, only if you kick it. So do I just need a new ecu or is there anything else I should try. Thanks for any help!!!! By the way im new to here and have a feeling I will be on here alot as long as I own this thing. It sat next to a house for 12 years before I got suck in to buying it for $100.00

Here is a before and now pic

 

appears to be a cold solder problem, or crack in the tracks on the ECU board, if you got skills with soldering iron, then it is easy to solve, making new welding, repairing the damage. good luck

 

there are some grounds and spliced wires in the wiring harness that could be your problem otherwise read my general advice could be as innocent as battery system problem

Get your battery load tested. Be sure you have clean, tight corrosion free terminals on both ends of your battery cables. Be sure the ground (negative) cable goes to a bolt into the frame before going to the starter. grounding through the starter is not a reliable connection. Z's don't like low voltage. causes the electronics to act funny. it is possible to have enough amps to crank but not enough voltage to run the electronics. If you have one size fit all cheapo clamp on terminals they are a problem waiting to happen.

Clean the connectors for the maf, ecu and tps. Deoxit by CAIG is probably the best connector cleaner on the market. spray with CorrosionX after cleaning and before putting together this will help prevent any further corrosion.

Replace outer tie rod ends, and ball joints. replace the bushings with poly (don't forget to lube them as directed unless you like squeaky things). New shocks. all those things will make you think you are driving a different car. doing them piece meal is a waste you won't see a great improvement until you do the complete job. Rear bushings nice too but more work and you won't notice as great an improvement. Rear shocks also because if the fronts are gone so are the rears. if car squats when you jump on the gas the rears are gone. If you have the electro adjustable shocks they are DEFINITELY GONE.

but for a $100 you can put a lot of money into it for improvements in driveability and reliability

if you have the one size fit all battery terminals shown then some dark and stormy night you will be sorry.

 

thanks for the reply! I did take the sleeve off of the computer to look for anything obvious and did not see anything, is there a way to test for any hair line cracks besides a magnifying glass? I know for welding there is a powder to help find cracks, is there anything like that for electrical?

 

Rogerz- I did have the new batt. Tested that led to the new alt. New cables with ground to body first. I cleaned all connectors, and have tested all grounds at least 1 inch up wire with power prob. I had dash out for heater core so I checked anything I could find under there at that time. Is there any other grounds tied to ecu somewhere else I could re check?

 

Well I re-checked any ground I could find. What I did find is, while ign is on I can move the ecu plug and nothing happens but if I tap the ecu with a screwdriver I can get it to freak out, tap it some more and it will stop. So is there anything else I should check before I order a new ecu, and where do you guys recommend to get it from.

 

Did you reseat the connector to the ECU?

 

Yes I did with grease after cleaning the pins again. Its getting worse it was only freaking out every now and then when driving, but today it did it 6 times. I'm nervous that it might not kick back to life and I'll be stuck. But I want to be sure before dropping a few hundred.

 

ARGHHH! DON'T PUT GREASE ON ELECTRICAL CONNECTORS! That's for everyone - not just pointed at you matice00. Sorry for the yelling but that has to be the hardest myth to die and so frustrating that people tell other's who don't know that it's a good idea. What do you use grease for (other than electrical connectors)? To PREVENT metal-to-metal contact! That's what lubricants do. When you prevent metal-to-metal contact in an electrical connector you prevent the electricity from flowing! You will get some sort of metal contact since it will work but as you increase the ammount of current required to go through the connector you will cause heating and oxidization and eventually failure of the connector. It's a bad, bad, bad idea. Some connectors are over rated and can handle a partial connection so people get the idea that it's ok because they tried it and it worked for years with no problems. Yes it does keep water out and prevent corrosion but there are better ways to do it without reducing the capability of the connector.

 

I never have before, just on spark plug wires so they won't rip the boot off, but searching on here its talked about a lot so I thought I would try. But it has been freaking out well before the grease, with just using elec cleaner and a small wire brush to clean the pins.