Superchargedk20

I took my evo out of storage . Put about 100 miles on it and it ran great. Drove it earlier today and notice a slight buck/misfire. It started to do this when just giving it the slightest of gas just cruising. Shortly after the car just died.
I gave it a couple cranks and it felt like it was going to start but it wouldn't. I waited a bit and it started. Thankfully it died on my street. I went around the block and the small misfire is still present and the car continues to die after a minute or 2 of just driving. I haven't modified this car in yrs and it's never given me problems like this.

I noticed the other day the walbro fuel pump sounded alot louder than usual. I didn't think anything of It because it always whines. But now after this issue and only 1/4 fuel in the tank the pump is very quiet. I can still hear it working but I have to put my ear up to the rear wheel to hear it when just the other day it was whining so loud I thought there was a problem. I don't drive this car often but I could've sworn when I would put the key to position II , I would hear the pump prime. Now I don't hear anything but the car still starts. I'm leaning towards either the pump is failing or the relay is going bad.

I'm not mechanic savy but I def can't get this to my mechanic given it's just shutting off. Any ideas?

deylag

iTrader: (23)

oh yea i had the same problem a couple years ago. Glad I was able to fix it!

sunnysideup

pump could be failing or it’s not getting enough power whether through a bad ground, relay or wiring. You can probably start by checking voltage at the fuel hanger or changing the relay.

Superchargedk20

what was your solution

Superchargedk20

Another thing I should add. When the car is in gear and it "dies" . The power steering stops but the rpms continue to decelerate if the car is in gear.

schuhie

The pump won't prime unless the car is cranking so you won't hear the pump with the key in the "on" position unless the car is running.

From the sounds of it, I would venture to guess its likely fuel related but its really hard to say.

My first test would be to check fuel pressure at the rail. You can do this with a tester rented from an auto parts store and it should be right around 43.5 psi. You will have to crank the car to get a pressure reading.

Checking the voltage at the pump would be the second thing I would check based on the results of the fuel pressure test.

If there is fuel pressure, it gets a little more complicated as it could be injectors (unlikely) or a bad coilpack (more likely) or some other sensor (cam, crank, etc). Troubleshooting those gets a fair bit more involved and will require a good scan tool to really get a handle on it.

Superchargedk20

thanks for all the tips! I should also mention there's no CEL on. I will be getting the car towed to my mechanic next week. Hopefully it's not something major.

Superchargedk20

Video provided . Just shut off again. This time it won't start up..

It died on the street next to mine. Like 3 houses away. Called a tow truck. Walked home. Played gt7 for 30 mins. Walked back and it started lol.

schuhie

Alright so it still sputters when it won't start, that's a good thing. To me, this looks like fuel pressure is probably your issue. Could be a pump or the fuel pressure regulator. Those are the first 2 things I would check and both are and easy check with the previously mentioned fuel pressure tester.

Considering it seems temperature related given that it started back up after it cooled some, I would be giving a hard look at the regulator personally.

Whatever is found, please post back the fix for others.

Superchargedk20

I definitely will. I've searched high and low on the forums and it boggles my mind how so many people here make a thread about an issue but never post their results. I don't post here much but I def will post the outcome. Just glad i got her home safe if its the pump i will be getting rid of walbro and switching to the aem 340lph. Do you know if a bigger pump will mess with my tune since I was tuned on a walbro 255?

schuhie

Why swap from the wally? They are great pumps and work with the stock fuel pressure regulator well; I am not sure the 340 would.

It may or may not need to be tuned depending on how the fuel pressure regulator takes it. I guess in the case if overruns it, you could replace with an aftermarket regulator and probably get away without tuning but I'd definitely be logging and comparing to old logs to make sure its all good.

Superchargedk20

I only bring this up if its the pump failing. Because a pump that has maybe 12k miles on it and it fails isnt a part I want to replace with the same brand. Again just in case it's the FP and not something else. I contacted my tuner and he said the same thing as you. But he also said a DW 255 would be a good alternate If i didn't want to go the walbro route.

schuhie

I mean, wally's don't generally die young like that. I have had the same 2 in my car for 40k miles. Its likely you got a bad one and honestly, walbro might even warranty it if you wanted to go that route if it proves out to be the fuel pump.

I'm not experienced enough with the AEM or DW options to say they are better or worse for reliability and fuel delivery but I can say I have run a **** load of wallys without early failures. I wouldn't want you to write off the proven option that you are already setup for with 1 bad experience.

I didn't realize you only have 12k on the pump, to me that points even stronger to the FPR.

Superchargedk20

Def a valid point. I bought this car stock with just over 16k miles about 8 years ago. Now 8yrs later it just broke 33k this yr. I did a basic bolton build and haven't touched it in years. I'll hopefully have more answers Monday

deylag

iTrader: (23)

Yea the map sensor is faulty. Reading the replies and seeing what the Evo is doing its the symptoms of a bad map sensor. You will need to get an OEM Evo X Map sensor to fix this issue. My experience tells me it was an Omni 4 Bar map sensor that failed on your Evo.

Do a quick test while trying to start the engine. Unplug the MAF sensor and see what happens. Then unplug the MAP sensor and see what happens. Then unplug both sensors and see what happens.