Okay so i bought this 1990 hatchback DX in not running condition for $600. Guy told me 100% it was the fuel pump, but he just didn't want to do the work himself.

Towed it to my house, got a fuel pump, dropped the tank, replaced the pump, and low and behold it runs. Sort of. Idles decently, but as soon as you give it 1/3 throttle, it starts bogging down. Foot to the floor, it'll stay running, but barely. After about 30 secs, it'll rev as it normally would at WOT, even if you let off the throttle entirely. I drove it for a few minutes to see if that would make it run smoother, with no luck.

I then took it home, parked it for about eight hours, tried to start it again and boom, won't start. Cranks for days, fuel pump primes, master relay clicks, but no fuel comes out of my fuel filter.

what do i do next?

 

Dayuuuummmm. Did you take out all the old gas and water out of the tank before you put it back in? Did you put new gas in it? I'd put some fuel stabilizer/cleaner in the tank, and I would make sure your fuel pump bag catcher thing is connected properly. I would change your fuel filter as well.

As far as not getting any pressure to the fuel filter, make sure you have at least 50% fuel in the tank, you should check for leaks from your fuel tank to your fuel filter. Otherwise, you may have another dead pump.

 

I just tried it again and it started! still idles perfectly but as soon as you put some gas into it, it tries to die. It was ran dry when i bought it and i filledi t to 2/3s of a tank. fuel cleaner sounds like a great idea, i'm definitely gonna pick some up, and i'll check out the fuel filter tonight. dude i bought it from said he replaced it, but who knows.

 

what else could it possibly be?

 

Could still be the main relay, I would remove it and re-solder the joints to be safe. Change fuel filter also. If those don't work, look at other issues such as fuel pump. But before you even go that far make sure your plug wires, plugs and ignition is all in order as well.

 

My plan is to replace plugs, wires and filter tomorrow when lordco opens. I did a bit more testing, the only time it bogs down really badly is from zero throttle to more then half. If you accelerate slowly, there's less of a chance of it bogging down and it'll keep running steadily enough . Also, after letting it idle for almost an hour it seems to have much better throttle response, as opposed to a "cold" start (it's 35*C + where i live).

 

Replaced the plugs and wires, started and ran it for 15 minutes (still bogging down). Shut it down, replaced the filter, haven't been able to get it started since. Anyone know how id go around replacing my fuel regulator?

Also, I'm going to rip out the main relay and resolder the connections tomorrow.

 

You have probably tried this by now but, there's a chance the motor is flooded. Try starting it and holding it at WOT. Even though it sounds like it's dying, if it stays on, it should get back to normal. Your symptoms sound like mine. This is what I did to get it to turn on.

 

Stop throwing parts at your car. Just because buddy told you it was fuel related doesn't mean anything.

Diagnose your issue and FIND the problem first.

 

I swear there should be a CEL. If not, check the obvious problems people have. Timing, FITV, IACV, throttle cable, etc. Make sure your sensors and such are functioning. Then check the distributor cap and rotor. Check your spark plug wire resistances to be within spec. Check your vacuum hoses for leaks. Check that you have all the correct vacuum hoses. Check for open ports. Check the MAP sensor for function. Check the TPS voltage.

You probably have a sensor on the verge of going bad that is causing you to have issue without a CEL (if your CEL even functions).

KP Nailed it. Tried and True advice. FIND the issue then FIX it. Throwing parts at the car won't help unless you get lucky.

With all that said, I know I'm a hypocrite. I'm having a hell of a time diagnosing my own issues.

 

Let a friend re-solder my main relay and he fried it, now not clicking on as it's supposed to. Throwing up a CEL as well. Looks like it'll be a couple weeks before she's running

 

Consider dropping the fuel tank and cleaning it out.
Pump could be sucking up garbage in the tank and plugging the sock.
... Or maybe you installed the sock wrong?

 

Stop doing this. Gather information and property diagnose the issue.

There's a saying... "Lazy people work twice as hard"...and in this case you're also spending twice the money needlessly replacing parts.

 

Oh I definitely learned my lesson there. Gonna go buy a voltimeter and do some more investigating

 

My red LED on my ECU doesn't blink... not even a single startup flash. any ideas?

 

A solid light means it's bad (or you have a bad ground or something).

Maybe the light is dead?

Have you measured your fuel pressure?

Made sure all your grounds are good? Especially the thermostat ground