Fuel Pump Resistor, what omhs?

OKGN

OKGN

Greenie N00B Member
Anyone know what the ohms need to be on the fuel pump resistor? Searching the web gets me varying number. Im getting 0.8-.9

Chasing an issue, trying to rule out fuel system components.

Symptoms if you are intrigued
When cold, it is long turnover but fires up and runs/drives normal.
Cleaned throttlebody and MAF sensor
Plugs were older and were white when pulled, kinda concerning, installed oem spec NGKs
When warm after starting cold, 30+ minute drive, it will randomly stall ONLY at sitting idle for several minutes
When warm starting, it will start then immediately stall. Revving above 3k will keep it alive. If I let it stall after keeping it alive by revving, it will only crank over and won't start until it cools down.

Only mod is CS short intake, unfortunately I do not have an accessport or similar tool to read fuel pressure which would prob tell me the issue haha.

Thanks!
 
Manual says like .30-.34 ohms or something like that but mine reads .8-.9 ohms too. I don’t know if it’s just varying suppliers or not, but you’re fine.


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Did the jumper test. Car started and idled for a bit. While idling I started jiggling the wire harness loom that the MAF pigtails run to and the car immediately died. Ill be peeling loom and electrical tape to inspect wiring next.

Thanks again
 
So far found one wire that had been rubbed exposed that runs to a ecu harness, either injector 3+4 or a ground, based on a 2007 pinout diagram. Patched it and still same symptoms. Dropped the fuel tank and replacing pump when it gets here.

Thanks for the MAF connector info, lots of info on that. That will be my next focus if the FP doesn't squash this issue.
 
If you order a new intank fuel pump from Mazda, you will need to order a filter for it as well, as I found out.
Note that I should have added to my first post is that my speed3 has 127k miles on the clock.

I replaced the intank pump and replaced the MAF harness with a S935 made by Standard Industries from Oreillys.
Note on the new MAF connector, I had to remove the soft rubber insulation boot from the new connector or else it would not push fully in to the MAF and "click/lock" in.

I did do a continuity test run down with a multi-meter on each MAF wire from the harness pin to each end and both the old and the new harness passed.

Results are great so far, no slow starting when cold and has not stalled at idle when warm. Weather wise its been in 50's, and the issues didn't start until temp outside was in the 80's so if a few more days when it warms up outside, I will rule out if outside temps were playing a factor. Fingers crossed.
 
OKGN said:
If you order a new intank fuel pump from Mazda, you will need to order a filter for it as well, as I found out.
Note that I should have added to my first post is that my speed3 has 127k miles on the clock.

I replaced the intank pump and replaced the MAF harness with a S935 made by Standard Industries from Oreillys.
Note on the new MAF connector, I had to remove the soft rubber insulation boot from the new connector or else it would not push fully in to the MAF and "click/lock" in.

I did do a continuity test run down with a multi-meter on each MAF wire from the harness pin to each end and both the old and the new harness passed.

Results are great so far, no slow starting when cold and has not stalled at idle when warm. Weather wise its been in 50's, and the issues didn't start until temp outside was in the 80's so if a few more days when it warms up outside, I will rule out if outside temps were playing a factor. Fingers crossed.
Click to expand...
Good to know, you could have also slapped an AEM fuel pump in there if you ever plan to need more fuel. They are drop in and will pump more for future PI. They are likely cheaper than OEM as well. AEM 50-1200 E85 In-Tank Fuel Pump

Template public:_media_site_embed_amazon not found. Try rebuilding or reinstalling the s9e/MediaSites add-on.
 
Just weighing in with my results as well. I measured two presumably working ones, both came in at .40 ohms.

It does mention .32 ohms on the resistor itself.
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I've seen people bypass this. Is it OK to do with the two wires before the connector? I've seen people loop the wires together after the connector but my connector is bad and I'm stranded. Please help
 
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