Im freaking stumped - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

02specv89240 · 12-01-2012, 03:43 PM

First off i wanna say Im no noob, I dont claim to know everything i still have alot to learn, but Ive been playing with 240sx's and sr's for almost 5 years now and done 4 s13 swaps.

SO the story gose like this....
One weekend i noticed that everytime i hit a bump in the road my car (89 240sx sr redtop light mods) would lose fuel and fire for the duration of the bump then resume driving fine after bump. This went on for 2 days and the car ran great other wise plenty of power and no hickups. So day 3 gets here and i finally hit a big enough bump and it made the car shut off and it did not come bac on had it towed home. Wehn i got home i noticed the fuel pump did not prime up when hitting the key this made me look at my ecu. The ecu wasnt coming on wich means no fuel pump power and or spark of course. So i started tracing the wires and seeing where i have power and where i do not. when fiddling around with the relays and wires i noticed that when i push hard on the top of the egi relay (to manually connect terminals inside) with the key on the pump would prime the ecu woulp get power and as long as i didnt turn the key off before trying to start it, it would start right up and run fine.

So from there I had jus bought a new chassy about 2 months prior a 92. Since i had the car off the road i decided to go ahead and swap everything over from my 89 (rust bucket) to my 92. When i did this the car started up fine just by turning the key. But only for the first day. I started the car drove the car hit bumps to make sure it wouldnt cut out anymore and everything was great. next day i go out to take the car to a buddys shop to weld my exhaust back up and of course no go unless i mannually engaged the relay. (Heres a funny note about that the car will work with relay in and me mannually connecting terminals but if i take out the relay and use jumper wires instead then its a no go. so i let the car sit for a month or 2.

So 2 dayz ago i got a hair up my ass and said this car will be fixed 2day.....that was 3 dayz ago. I started out by installing my own relay.
I kno the ecu has to have power to give the egi relay power to give ecu full power. So i used a separate relay to turn the egi relay on and wire it to a toggle switch. This kinda worked...... as in if u hit the switch and turned the key to the on position the pump would prime right and ecu would power up. but still no start cuz now as soon as the key hits the start position ecu gose off WTF. this made take my relay bac out and put everything to factory to see if it would go bac to turning on if i hit the egi relay. no go it wont turn on at all now. Then i put my relay bac in and used a different power source and have power when hitting the switch i get power but the relays dont activate, but if take the egi relay out and jump it with a wire i get power to the ecu once again but still no power when key is at start position. so this is where im at now and have ran out of ideas any input would help so please anyone give it a stab cuz my head hurts now none of this makes sense to me.

KiLLeR2001 · 12-01-2012, 03:56 PM

Did you ever consider that you may have a bad ECU? I would swap in a known working ECU if you can and go from there. One day my ECU stopped priming my fuel pump, drove me crazy until I replaced the ECU and problem solved.

ivankol · 12-03-2012, 01:07 AM

have you checked your clutch interlock relay by the battery tray?

12-01-2012, 03:43 PM	#1
02specv89240 Join Date: Oct 2009 Location: Florida Posts: 1 Trader Rating: (0) Feedback Score: 0 reviews	Im freaking stumped First off i wanna say Im no noob, I dont claim to know everything i still have alot to learn, but Ive been playing with 240sx's and sr's for almost 5 years now and done 4 s13 swaps. SO the story gose like this.... One weekend i noticed that everytime i hit a bump in the road my car (89 240sx sr redtop light mods) would lose fuel and fire for the duration of the bump then resume driving fine after bump. This went on for 2 days and the car ran great other wise plenty of power and no hickups. So day 3 gets here and i finally hit a big enough bump and it made the car shut off and it did not come bac on had it towed home. Wehn i got home i noticed the fuel pump did not prime up when hitting the key this made me look at my ecu. The ecu wasnt coming on wich means no fuel pump power and or spark of course. So i started tracing the wires and seeing where i have power and where i do not. when fiddling around with the relays and wires i noticed that when i push hard on the top of the egi relay (to manually connect terminals inside) with the key on the pump would prime the ecu woulp get power and as long as i didnt turn the key off before trying to start it, it would start right up and run fine. So from there I had jus bought a new chassy about 2 months prior a 92. Since i had the car off the road i decided to go ahead and swap everything over from my 89 (rust bucket) to my 92. When i did this the car started up fine just by turning the key. But only for the first day. I started the car drove the car hit bumps to make sure it wouldnt cut out anymore and everything was great. next day i go out to take the car to a buddys shop to weld my exhaust back up and of course no go unless i mannually engaged the relay. (Heres a funny note about that the car will work with relay in and me mannually connecting terminals but if i take out the relay and use jumper wires instead then its a no go. so i let the car sit for a month or 2. So 2 dayz ago i got a hair up my ass and said this car will be fixed 2day.....that was 3 dayz ago. I started out by installing my own relay. I kno the ecu has to have power to give the egi relay power to give ecu full power. So i used a separate relay to turn the egi relay on and wire it to a toggle switch. This kinda worked...... as in if u hit the switch and turned the key to the on position the pump would prime right and ecu would power up. but still no start cuz now as soon as the key hits the start position ecu gose off WTF. this made take my relay bac out and put everything to factory to see if it would go bac to turning on if i hit the egi relay. no go it wont turn on at all now. Then i put my relay bac in and used a different power source and have power when hitting the switch i get power but the relays dont activate, but if take the egi relay out and jump it with a wire i get power to the ecu once again but still no power when key is at start position. so this is where im at now and have ran out of ideas any input would help so please anyone give it a stab cuz my head hurts now none of this makes sense to me.

12-01-2012, 03:56 PM	#2
KiLLeR2001 Post Whore! Join Date: Jun 2007 Location: オーランドフロリダ Posts: 7,955 Trader Rating: (46) Feedback Score: 46 reviews	Did you ever consider that you may have a bad ECU? I would swap in a known working ECU if you can and go from there. One day my ECU stopped priming my fuel pump, drove me crazy until I replaced the ECU and problem solved. __________________

12-03-2012, 01:07 AM	#3
ivankol Zilvia Member Join Date: Jan 2008 Location: in my house Age: 35 Posts: 229 Trader Rating: (3) Feedback Score: 3 reviews	have you checked your clutch interlock relay by the battery tray?