Fuel issue

[PumpdUpKicks]

Hey guys.
On Tuesday the car was running great, just recently did ignition tune up, fuel filter, all that basic stuff. But as of Tuesday the car was running great, no idle issues no throttle issues. Today I go to start the car again and the idle is ridiculous, just surging like crazy and it eventually dies. I assume fuel pump, grab my multimeter and test continuity on the pump and it's good, then tested the plug when trying to start the car and it was at 12V. So I unplugged the feed line to the fuel filter, now should I be getting fuel out of it while trying to crank the car? Because I'm not. But when I did connect the Hose back to the filter it would idle rough and then eventually even out to a smooth idle and proceed to die. But before I removed the hose it wouldn't run longer than 5 seconds, after I removed and put back on id say it ran for about a minute.

[PumpdUpKicks]

I got the car to again start up and I gave it gas and it died instantly. So definitely a fuel issue.

[PumpdUpKicks]

Bump. Anybody?

[packratbimmer]

How was the car running before the tune? I would go back through all of the work and check item by item. Fuel filter in backward? Wrong plugs? Bad/cheap wires?

[PumpdUpKicks]

it was running alright before, and then like perfect afterwards for about 2 weeks up until yesterday all the sudden. like i said, tuesday i let in run for a solid 15 mins (poured some seafoam into the gas tank) to let the seafoam works its magic. shut the car off, put it in the garage. went to start it back up friday morning and it had surging idle and eventually died.

[PumpdUpKicks]

yesterday i was getting 12v at the plug while trying to start the car, today im not. i replaced the relay with another good working relay and still no power. could a faulty CPS not allow power to the fuel pump?

[packratbimmer]

Maybe you stirred up a bunch of 25 year old gunk and need to flush the fuel system and clean the injectors?

[PumpdUpKicks]

I checked resistance on my CPS and I was getting a reading of around 550, which from what I've read means it's within parameters. I also check voltage of my fuel relay socket and was getting 11.7 with key turned one click, which is fine as well. I'm stumped.

[PumpdUpKicks]

Another update. So I Hooked the fuel pump up to a 12v battery, the pump turned on instantly. Started the car, it was a little hesitant with a wild surge,gave it gas and boom the car is back to normal running standards. So I've narrowed it down to being an electrical problem. Was getting good resistance reading to my CPS, 12v to the fuel relay socket, and continuity on my relay switch, and replaced it with a known working problem with no success. So now what should I check for? Could it be the DME? the car was sitting for about a year before I did maintenance on it as noted above, but before that it did have issues of suddenly losing power while driving.

[RoDo]

So it still won't run unless you hook the fuel pump up to an external 12V source?

[PumpdUpKicks]

So it still won't run unless you hook the fuel pump up to an external 12V source?

Yes that correct. I tested the hot lead and ground that go to the pump and wasn't getting power though. Although everything else was getting power.

Now I know it's possible to run a switch to the battery to manually turn the pump on and off, but if I were to do that, would it flood the car after a while?

[RoDo]

I'm not sure how much this would help but I've been troubleshooting a bad misfire on my car and recently went through a bunch of tests at the DME connector.

I used this article as a reference: http://www.rtsauto.com/ecu-pinout-an...cal-tests-e30/

If you jumper pins 2 & 36 at the connector, then connect 3 to ground your fuel pump should fire and you will hear it. This tests wiring from DME connector through fuel pump relay to the pump. I'm guessing it won't work on your car but who knows. Is it possible you have a short and the fuel pump relay you swapped in got fried?

[PumpdUpKicks]

I'm not sure how much this would help but I've been troubleshooting a bad misfire on my car and recently went through a bunch of tests at the DME connector.

I used this article as a reference: http://www.rtsauto.com/ecu-pinout-an...cal-tests-e30/

If you jumper pins 2 & 36 at the connector, then connect 3 to ground your fuel pump should fire and you will hear it. This tests wiring from DME connector through fuel pump relay to the pump. I'm guessing it won't work on your car but who knows. Is it possible you have a short and the fuel pump relay you swapped in got fried?

Thanks for the article. And if I placed a jumper wire in the fuel relay it shouldn't matter right?

[RoDo]

Thanks for the article. And if I placed a jumper wire in the fuel relay it shouldn't matter right?

I'm no expert but I think if you try the test from the DME connector and it doesn't work then the next step I'd try would be to pull the relay and jumper that with a fused link to see if the pump will fire. Also have you checked the fusebox?

[PumpdUpKicks]

Soo. I had a jumper wire in #11 the car ran fine, no issues. Replaced the jumper wire with another fuse, ran great for about 5 minutes and the car shut off, boom fuse broken. So I've got a short. So now the hunt begins, any ideas where to look?