Cruzn620 Posted March 25, 2015 Report Share Posted March 25, 2015 These last little things are killing my KA-swap project! Ok, If I pour a little fuel into the throttle body the truck will run fine for a few seconds, but when the fuel pump is running, it won't even start. I have pulled the line off a few times thinking their may be air trapped in the system, I ran the pump with the fuel line off just to watch it push fuel (holy crap the walbro pushes some fuel!) but no matter what, the motor is acting like it isn't getting fuel. Is there a purge procedure I'm missing? Any help is appreciated! Quote Link to comment
ggzilla Posted March 25, 2015 Report Share Posted March 25, 2015 Sounds like the injector isn't working . Check for pulsing. Quote Link to comment
kelowg Posted March 25, 2015 Report Share Posted March 25, 2015 bad fuel press reg? ck line pressure goin to injectors Quote Link to comment
Stoffregen Motorsports Posted March 26, 2015 Report Share Posted March 26, 2015 This may be frowned upon by the safety team, but I would crack the banjo fitting where the fuel line hits the fuel rail. If the pump is getting fuel to the rail, a fine spray of fuel will come out (under pressure so be careful). If there is no pressure there then that tells you there is a problem upstream. If there is fuel there, then your injector wiring may be at fault, or any number of other sensor, connector, ignitor, ECU issues. Quote Link to comment
Cruzn620 Posted March 26, 2015 Author Report Share Posted March 26, 2015 A little back ground on my swap if this helps, I pulled EVERYTHING engine, transmission, wiring, from my running hardbody. I drove the hardbody to the shop, stripped it, and began the retro fit. This is also a KA24E, not a DE, so I'm sure a few things are different. I'll try the banjo bolt deal because safety is just a suggestion...hahahahaha. I'm pretty sure this is an OBD-1 vehicle, and if that's correct the data wouldn't be detailed enough to tell me through a scanner where my problem was...correct? Another thing...to get the pump to work, I just ran a temporary "hot" wire, from the pump to the battery, just to make sure the pump worked and such. Could jumping around the fuel pump relay have anything to do with this? Like a signal from the ECU that if the fuel pump relay isn't open not to open an injector or something? Thanks for all the help. These last little things are killing me! Quote Link to comment
Stoffregen Motorsports Posted March 26, 2015 Report Share Posted March 26, 2015 I'm not exactly sure what type of system is used for the KA24E, but a circuit opening relay is sometimes used to fire the fuel pump. It won't give power to the fuel pump until it senses spark from the ignitor. It may sound like a lot of work, but when I do an EFI engine swap, I usually try to use the complete wiring harness from the donor vehicle, depending varying factors of course. Are you using the donor wiring? If not, why not? Scanners are not as cool as everyone thinks. They usually point to a direction that can be misleading. They are good at pointing to a symptom rather than an actual fault. Have you checked the wiring on the injector harness? If the grounds are not secured, that could lead to the injectors not firing. Also, there may be a way to manually fire the injectors by tricking them. You need to have a good wiring schematic to figure out how to do this. Quote Link to comment
Cruzn620 Posted March 26, 2015 Author Report Share Posted March 26, 2015 I used ALL of the wiring from the donor vehicle. The only datsun wires left on the truck are pig tails from the lights. It is possible that I missed a ground on the engine bay, but I hooked all of the engine bay stuff up the same day as I did the swap so I wouldn't forget anything. I have a feeling this is something really really small, like a ground, but it's driving me nuts! SO CLOSE TO HAVING IT RUNNING! The ignitor issue sounds pretty plausible because when I had the pump hooked up to the factory harness, it ran for about 5 seconds then after I attempted to start it, it never turned on again...so I could see something happening there. That is why I ran a temporary hot wire to it, to make sure my pump wasn't screwed. As for a wiring diagram, I downloaded one and it was like 40 pages, but when I dig into it, it seems like it isn't super detailed. I'll look over it again and see if there is a way I can jumper the injectors. I also haven't had the chance to check for fuel pressure at the banjo yet either, so that is something I need to check. Thank you for all of your help!! Quote Link to comment
Stoffregen Motorsports Posted March 27, 2015 Report Share Posted March 27, 2015 Good luck! Quote Link to comment
ggzilla Posted March 27, 2015 Report Share Posted March 27, 2015 http://www.google.com/search?q=noid+light Only $15 Quote Link to comment
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