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-   -   Fuel pump not coming on with diagnostic junper. (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/fuel-pump-not-coming-diagnostic-junper-1125538/)

MK3Brent 04-21-18 11:26 AM

Fuel pump not coming on with diagnostic junper.
 
What’s up guys!
Welp, I took the FD out for an hour drive this morning.
Everything ran great.
Parked for about an hour, then wouldn’t start.
I wasn’t hearing the fuel pump come on, so I jumped the terminals at the diagnostic block to test.
Nothing.
I checked the 20A fuse under the dash, and it seems fine.
Unfortunately I don’t have any tools with me, but wanted to see what other tricks I can try?


Maybe the FP relay? Can I swap any of the relays to test?
thanks!

arghx 04-21-18 12:06 PM

Can we get a mod list? Has anything been modified related to the fuel pump?

Gen2n3 04-21-18 12:21 PM

Have you checked the EGI fuse in the engine bay?

MK3Brent 04-21-18 12:27 PM


Originally Posted by arghx (Post 12269595)
Can we get a mod list? Has anything been modified related to the fuel pump?

mods are basic performance upgrades. Walbro fuel pump.
Stock injectors, rails, lines, and pressure reg.
Wiring to the pump is all stock too.
I知 at my buddy痴 shop now so I値l grab a multi meter and see if I知 getting any voltage back there.
Failing that, I値l hot wire the pump to see if she chooches.

Yes, I checked the EGI fuse, as I first thought it might have been flooded.
Visually it looks fine, I値l put a continuity test on it when I get back to double check.

MK3Brent 04-21-18 03:10 PM

Ok this is strange.
I can hotwire the fuel pump and I can hear it come on, but no start.
I went to check codes, and with TEN and GDN shorted, I only get a solid CEL. It won’t blink for codes. Only solid.
When I shorted the fuel pump terminals on the diagnostic block, the pump wouldn’t come on either.

Could this be something else, or did something happen to my ECU?

i tried using a small segment of copper wire instead of the paper clip for the junper, but that didn’t make a difference.

Thoughts?

MK3Brent 04-21-18 06:49 PM

Problem resolved:
We removed, then re-installed the EGI relay.
Pulled and cleaned the 15A Engine fuse located under the dash, driver's side kick panel.

Must be a loose/old connection(s) I'm guessing.

Thanks guys,

alexdimen 04-23-18 02:28 PM

I had an intermittent no fuel problem recently. Turned out to be a flaky wiring connector in the fuel pump bulkhead. The one that goes thru the fuel pump hanger... terminal inside had corroded and wasn't making a good connection.

Might wanna check that... better safe than sorry. Had to fully unplug the connector to see the damage on mine.

Also, I'd like more people to confirm this but I don't think my pump stays on continuously when I jumper FP and GND either. I need to try again with my new pump setup and wiring.

MK3Brent 04-23-18 03:09 PM


Originally Posted by alexdimen (Post 12270072)
I had an intermittent no fuel problem recently. Turned out to be a flaky wiring connector in the fuel pump bulkhead. The one that goes thru the fuel pump hanger... terminal inside had corroded and wasn't making a good connection.

Might wanna check that... better safe than sorry. Had to fully unplug the connector to see the damage on mine.

Also, I'd like more people to confirm this but I don't think my pump stays on continuously when I jumper FP and GND either. I need to try again with my new pump setup and wiring.

Thanks for sharing your experience.

My problem ended up being the EGI relay. More specifically the connection made from the relay to the junction box.
What I learned that's interesting, is that if this relay isn't operating normally... it won't allow you to check codes.

dabigesii 05-02-18 10:49 AM


Originally Posted by alexdimen (Post 12270072)
I had an intermittent no fuel problem recently. Turned out to be a flaky wiring connector in the fuel pump bulkhead. The one that goes thru the fuel pump hanger... terminal inside had corroded and wasn't making a good connection.

Might wanna check that... better safe than sorry. Had to fully unplug the connector to see the damage on mine.

Also, I'd like more people to confirm this but I don't think my pump stays on continuously when I jumper FP and GND either. I need to try again with my new pump setup and wiring.

I had this issue a few weeks back, and this was the cause.


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