94 ex won't start(fuel pump issues)

ECU, Wiring, Sensors
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94 ex won't start(fuel pump issues)

By panic989
- Thu Jul 17, 2014 5:30 am #347180 Hey guys. First off I would like to say hello again. I haven't been on here in quite some time now. I ended up selling my hatch and I just say I miss it. Lol.

On to the problem though... Alright so my sister was given a 94 dx from my step dad who bought the car from the original owner less than a year ago. There was an issue before where on a humid day (keep in mind I live in AZ where there is relatively no humidity) the fuel pump wouldn't kick on. I replaced the fuel pump for her just a few days ago with a brand new one and it started right up. Drove it back to the house (maybe 2 miles from where I changed it) and parked it for the night, she went out the next morning t drive it and nothing, won't start again. Pushed it up into the garage and started doing some troubleshooting according to the Chilton's manual (jumping 5 to 7 on the relay plug and so on) and thought that the main relay was bad so she bought one of those and replaced it and still nothing. No power to the fuel pump. Took the old relay and soldered 5-7 just to see if it would run and the fuel pump kicked n but it still wouldn't turn over. I went out tonight and did a little looking around on the inter webs and checked the ecu fuse and it's good. I didn't get into the pins on the ecu just yet but That is in the next day or so. Also I checked the ground on the motor and it was still good so it's grounded properly. I'm pretty much stumped at this point. Any help is greatly appreciate ladies and gentlemen.
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By teal_dx
- Thu Jul 17, 2014 1:31 pm #347189 I guessed Main relay as soon as I started reading your post. Since you already replaced that, I'm suspicious of your grounds and battery connections.

How do the grounds on your battery look? Any corrosion on them and are they tight? You already checked the engine grounds, but did you get all 3?
Valve cover, tranny and most important of all, thermostat housing. :thumb:
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By panic989
- Thu Jul 17, 2014 3:41 pm #347193 Battery connections are all good. No corrosion on the leads, and everything is tight.

You know what I may have missed the thermostat housing. I'll go check that out later today and post up those results later. Thanks teal.
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By panic989
- Fri Jul 18, 2014 2:27 am #347207 Checked the thermostat housing and I don't even see a ground wire. I never really messed with the SOHC Hondas so I don't know where it should be grounding to (the block maybe)? I had a gsr in my hatch and I don't ever remember having a ground on the t stat...
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By panic989
- Fri Jul 18, 2014 2:57 am #347212 I am reading continuity between all of the grounds.
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By panic989
- Fri Jul 18, 2014 4:28 am #347217 Oh and I forgot to mention in the OP that there was a jammy little security system in it that my sister and step dad cut out of it for some reason. As far as I knew it didn't work because they didn't have the pager for it but I'm not entirely sure. I also wasn't there for the hack job of pulling it out either. But it didn't seem that crazy or that it would tie into anything major but it may have... Idk.

By Axix23
- Tue Jul 22, 2014 8:38 pm #347289 When you say it doesn't start, does the car crank at all?
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By panic989
- Mon Jul 28, 2014 7:02 am #347465 Sorry for the late reply guys. We had the car started for a bit.

Axix23 - Yes the car cranks over it just doesn't want to start.

It only happens on humid days. It stated fine earlier today but it started to rain this evening and now the fuel pump doesn't kick on. I tried the main relay test again and it works and the fuel pump kicks on using the 5 to 7 jump on the main relay plug and the fuel pump kicks on but with the main relay in it won't kick the fuel pump over. And this is a brand new main relay installed last weekend. I'm stumped again peeps.
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By ihavesol93
- Mon Jul 28, 2014 7:17 am #347466 still is probably main relay, they are extremely common to go out in humidity and hot climates. i got stuck on the side of the road when mine cut out. it was 107 and only 4% humidity. i was out there for 2 hours.
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By panic989
- Mon Jul 28, 2014 7:21 am #347467 So the weather is actually playing into it then? This morning and most of the day was bright and sunny around 100° and it got cloudy when the sun was going down about 8 and wouldn't start when she went out to drive it at 11 after it had rained. But two weeks for a brand new main relay to go out seems a little odd.
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By ihavesol93
- Mon Jul 28, 2014 8:04 am #347468 the temp isn't supposed to mess with it, the way they were designed from the factory they are prone to a dry sauter and the joint for the resisters with crack. (maybe not the right engineering terms but you get it.)
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By panic989
- Mon Jul 28, 2014 5:32 pm #347480 Even on the new relay touch isn't really a relay in the sense that we think with clicking relays inside but micro chips?

By Axix23
- Sun Aug 03, 2014 6:21 am #347630 have you checked your spark plugs, ignition wires, and also the harness by the distrub? One time, my car kept cranking but it didn't start b/c one of my wiring plugs wasn't all the way inside. Do you have another fuel pump you can swap out just to rule it out? Have you pulled the fuel pump back out just to make sure that the hose didn't come off or is loose?
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By panic989
- Sun Aug 03, 2014 6:25 am #347631 We put a brand new pump in. All the wrote and connections are good. We narrowed it down to something is getting wet and sorting out on humid days. Just gotta take a day out and track down wires. Gonna be a p.i.t.a. to do. Lol
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