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Old 04-29-2010, 09:43 AM   #1
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Default Way too much fuel

So I've got the ms hooked up to my 90. I had a friend do it and he just guessed at some settings to get it to run at idle with 550cc injectors. It ran fine for a bit (few minutes), but then I noticed a large puddle of gasoline under the exhaust exit and the oil pan was also full of gas. Any way after a good sized fire and some other poking around I figured out that I have too much fuel.

Can anyone clarify what you do to the fuel pump relay when you run the megasquirt as a stand alone? I jumped the light green and purple wires together, but now the fuel pump runs all the time the key is on. It doesn't just run for a second and shutoff like it used to. Also when the fuel pump is on, it sounds like I can hear fuel running up at the fuel rail. I've tried with two different sets of injectors (550's and stock) and it seems like fuel is still running. I haven't tried running it with the stock injectors yet since I just drained out all the gas/oil and have to go get some more.

Any ideas?
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Old 05-03-2010, 02:07 AM   #2
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I forget which Megasquirt you have Mike, do you have the MSPNP?
Where did you read that you needed to jumper the light green and purple wires together?
Does your friend know what he's doing or is he just guessing at lots of stuff?
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Old 05-05-2010, 04:09 PM   #3
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I as well have the fuel pump jumped on my MS1, and it also runs all the time the key is on. And I can tell you that with a Walbro 255 and an afpr mounted to the firewall, you hear every ounce of fuel running through those shiny pipes and hoses.

But...fuel running through fuel lines and back to the tank after it goes through the fuel pressure regulator should not mean you get fuel pooling in the oil pan and/or out the exhaust. You are too rich when you are cranking and/or running the car in idle. Sounds like you need to pull some fuel out of your map and try again.

If you are hard up, post back with at least what type of injectors you have and which MS you have, and someone (like me) could send you a map and idle settings that may at least get you close. I've got a boost tuned map for a 1.6, 1.6 throttle body, 450cc high impedence injectors. If you took this mapping, or the entire msq and changed reqfuel for the 550s, you'd at least have a runner/idler. Hell, I used just this method to get my 1.9 on 1000cc injectors squirting E85 idling and onto the trailer, it should work for you.
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Old 05-05-2010, 04:47 PM   #4
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Have you installed your wideband yet?

It is not a problem having your fuel pump working all the time, however I normally like it on a switch when I am dealing with a full out Racecar like you are. This way you can turn it off if need be.

My gut feeling is that your car is far too rich and you are passing unburnt fuel. The wideband would probbaly give us a quick idea if this is the case.
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