code 543

mmathews

Registered User
My car sputters under load from time to time. By load i mean high gear low rpm. And it has lost a bunch of power. I just did the head gaskets. I did an egr, ps and a/c delete. I searched and got a fuel pump vacuum line was a cause. Bad O2 sensors. Bad relay. Dying fuel pump. The code appeared after the head gaskets. Ran strong before. The head gaskets were not blown. Any ideas?
 
Its defiately running out of gas. When i pulled the injectors, some of the hats were chipped. I tried to get a replacement o ring kit but it hasnt come in yet. I sprayed carb n choke cleaner on them to clean out all the crap that was on them. Could they still be dirty? Anything i coulda messed up on the fpr? It idles smooth. Drives great til it calls for power. Then it sputters. Still goes ok but at 75% power.
 
I inspected things again and saw my bypass was shut at idle. I broke the vacuum line. That didnt fix the miss but now its much more consistent. Its actin like a plug issue more now. Sounds like an old subaru. Although i am definately open to what you guys think.
 
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Help! Ok, when i got home today, i checked all the plugs and wires. All is good. Its running like my fuel filter is clogged. But its new.
 
I went through this with my 94 5-speed. My code 543 was accompanied by a code 137, rich left O2 sensor. I replaced both O2 sensors, injectors, resealed the intercooler pipes, replaced every sensor in the engine bay, plugs, wires couldnt solve it. I found the thread that David just posted, checked the vacuum line, no luck. Checked all the vacuum lines, replaced them, pulled vacuum on them individually, pressurized the intake, no luck. I had found a couple of threads that suggested 543 was a problem with the fuel pump itself, but my problem was rich , not lean. If Davids link does not help I would suggest dropping the fuel tank, and pressurizing the vacuum line from the tank to the connection at the fire wall, ruling out damage from rust or road debris. I believe that vacuum line is steel from the front of the rocker all the way to the tank. But if your starving for fuel, it may just be that you fuel pump is on the fritz.
 
David, i got those lines all worked out. My line was actually missing from the canister. I attacthed to to the "T" in pcv hard line and to the steel pipe that runs up the strut tower. I put an inline fuel filter between the pcv and the metal vacuum on the plenum. Could that hurt it? My car never pulled codes or sputtered even without that line unhooked. Anything with the egr delete that can cause this? Its all gone. I read sometime an ecu will run in a "limp" mode. But not from an egr delete.


My fuel pump could be dying. It seems kinda odd that the car ran strong, i replace the head gaskets, clean things up and the pump is now dying. I know its possible but i would point the finger at myself first.

The cars fights to raise rpms. 70 mph is a chore for it. Any chance it could be an injector issue?
 
Lol! I have myself running in circles here. I reset the codes and went for a ride. The 543 code is gone. Now i have a lean condition left side code for both koeo and stored er. That makes more sense. Could it be an O2 sensor?
 
If you can remove your O2 sensors without damaging them, switch them around. If your lean condition moves to the right side then you know its your O2 sensor.
 
I unplugged it and ran it..i read that it will use the other side as a reference. It ran the same. I took the blower off and went over the injectors. All looked clean. They didnt seem to sit as deep as before so i reemed the fuel rain mount slots and set them a little deeper. Guess what? It still sputters! I was thinkin i would get new plug wires tomorrow. Would it throw a lean code with a bad wire? Seems backwards. Could i need bigger injectors? I am lost.
 
I did a fuel pressure check. All is ok. I also check for vacuum leaks. I did find 1 which prob cause the lean code at idle. I am gonna switch directions here and say the lean code is not applicable. I had to order plug wires. I had the firing order wrong when i first got er back together. I am thinkin i screwed up a wire or plug and the spark is weak. I am gonna replace the plugs and check the resistance of the wires. I am also gonna hose clamp all of my larger vacuum lines.
 
Fixed! The plug wire on #4 had a slice in the boot. Looks like previous owner grabbed it with pliers. It was near invisible. I ran the car at night and looked for arcs to detect leaks and didnt see it. Tonight i performed the same test while i worked the throttle and saw it up under the lower ic tube. I changed the routing when i did my hg and it musta rotated it closer to the exhaust. I slipped a piece of high pressure hose over the boot and ripped around. Car rips again. :)
 
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