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If the FP wire in the diag box has constant continuity to ground, the relay, and therefore the fuel pump, is going to stay constantly on. This is either because the MS for some reason is commanding the FP stay on, or there is a short to your chassis somewhere.
If the FP wire in the diag box has continuity to ground for only 3 seconds when you KOEO, then your relay is most likely sticking.
If you want to check at the relay socket, you won't hear the fuel pump obviously, but yes, you can stick your MM probe in the ground side of the relay's coil (light green) and test to see if it's staying grounded or not.
If it's MS related wouldn't it be a constant issue and not intermittent? Can I do the test you're recommending with the relay in the car?
Also, is there another compatible relay on the NB that I can swap with to test? I think the antenna or defroster relay was the same for the NA, but I don't think that's the case for the NB since I can't find part numbers that are interchangeable.
If your meter shows resistance with the probes isolated from everything, throw it away lol. I use a fluke, it shows 0 ohms when the probes are isolated and providing an open circuit.
If your meter shows resistance with the probes isolated from everything, throw it away lol. I use a fluke, it shows 0 ohms when the probes are isolated and providing an open circuit.
On continuity it reads a straight 1 with nothing touching it. If I touch the two probes together, it beeps showing continuity. It reads zero pretty much on all the other settings.
In any event, if this is the relay:
If I have it set to continuity and I have it on the two ones across from each other on the right in the image (with the holes), I get the MM beeping, i.e. showing continuity. This confirms that it's the relay right? Since it's not supposed to show continuity with the car off (no ground?)?
After I took the plug in and out under the dash, the relay worked as it was supposed to. Pulling the plug out and retesting the prongs as above showed the same thing. Honestly, it's like anytime it acts up, it starts acting fine if I pull the plug and put it back in... If it was the MS and not the relay, wouldn't pulling the plug out do nothing?
With continuity, the number was reading in the 60's or something.
Edit: NVM. This probably actually tested nothing because the relay wasn't getting power lol. But hey, it's kinda weird that unplugging and plugging back in seems to fix it.... I should be getting a relay shortly. Will test that and see if it makes the intermittent issue go away.
Originally Posted by curly
Well most likely it’s your cables, definitely replace those first.
Wires for the MM?
Last edited by ridethecliche; 09-17-2018 at 01:38 AM.
No that is the relay that powers the ecu and a whole ton of other stuff. The facturly fuel pump relay is next to the steering column. I think even the factory one of these is solid state (not certain because mine melted itself pretty shortly after upgrading the fuel pump) so it cant stick intermittently. It can fail in either energized or de-energized state though.
I can take a picture of the innards of the relay. I actually got a spare from a local guy that parts cars. I couldn't get the old one out from the housing so I took of the entire plate with all the relays and ended up swapping the innards of the relay while leaving the housing where it was so I wouldn't break it. It acts like it should on a cursory test. I'll find out if it too has an issue in the next few drives I suppose. I have the old one in the glove in case something happens. Picked up a spare main relay as well because reasons.
Hm. I upgraded to a dw200. That shouldn't change anything enough to require a different relay, no?
TLDR; On this episode of monkey's writing shakespeare, I just swapped the relay. Lets see if that 'fixes' the issue, if said issue is an old relay sticking intermittently.
You wouldn't think a dw200 would be an issue considering its draws well under 10 amps and I think it's a 30 amp relay but track guys are killing the relays with stock pumps.
Definitely in for results as I chose to skip dedicated fuel pump wiring when I did my dw200.
It takes an additional 30 mins or so to wire in a dedicated relay to power the fuel pump. It will allow the pump to see more stable voltage especially after everything starts heating up. I went the lazy route and bought the DW fuel pump hardwire kit. Which honestly is a ebay/amazon relay pigtail with 12v+ lead being like 10ft long with a chinese fuse holder, and a decent looking relay. $40. Id rather not worry or question how the DW200 pump is doing so I just opt to upgrade and be done with it.
Sure it could. While doing the fuel pump, OEM harness is fully accessible and it really can't be taking much time unless you are really unorganized with your tools and supplies and count the time it takes looking for all that lol. My point was it just doesn't take much to wire one in, then you know it's good!
I just did it a few months ago on my '95. It took me longer than 30 to do it making sure all the wiring was tidied up and not going to rub. I even installed the relay right next to the ECU (which is behind the passenger seat on the 94-97) which meant I didn't have run wiring all the way up to the dash.
The wire at the relay is spliced to the one at the diagnostic connector so they're electrically the same.
You need pictures and I can't make one until Wednesday. Hang tight or hope someone else has more time than I do.
I still would like to know the model of the meter you're using. It makes the spooning easier.
Plz poast when you get a chance haha. Everything seems to be working fine, but I can definitely hear things priming indefinitely when I first turn the key. After things warm up, it clicks off audibly.
The pump can't get power any other way than through the relay. Pulling the relay will definitely shut off the pump but that won't tell us anything we don't already know.
09-16-2018, 06:05 PM
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