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My 87 wrangler runs rich, idles rough, runs rough. guy put on an electric fuel pump. original carb. he said it needed a fuel pressure regulator. is he right?
Re: My 87 wrangler runs rich, idles rough, runs rough....
Sounds like it is flooding the carb, by putting a fuel pressure reg on it it will lower the pressure at the carb and stop overriding the float,needle and seat.
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Check the intake for vacuum leaks, use a can of carb spray and spray all over the gasket area where manifold mates to the cylinder head. If you hit a leak the engine will sound different. Also touch the EGR valve with wet fingers, it should be cool when idling, if it sizzles the water it is leaking and this causes a rough idle.
You could pay a garage to diagnose the problem cheaper than throwing more parts at it. The problems may be connected or they may be different issues. Yes I would change the oil and filter, but first I would make sure the fuel system is not dumping too much fuel into the cylinders. The O2 sensor helps the computer decide on how much fuel the engine needs, along with the other sensors. And you said you have already replaced the O2 sensor. A mechanic would take a scanner and "read" the sensors and look for something out of normal range. The fuel pump and fuel filter are off the list as far as causing a rich mixture goes. I would start with the rich mixture and then see if fixing that issue takes care of the no start when hot issue. Change the oil and filter first, and see if the injector is on too much. You can watch the spray and tell - at idle it should be very light. Also look at the engine temp - is it warming up to normal 195 degrees? Can you tell if the fuel pressure regulator is blown and pouring fuel into the throttle body ? Without a scanner its going to be more difficult, but not impossible to diagnose. Let me know what you find out.
Yes...check the pump, filter and output. Also check the ballast resistor for the pump. Stop pouring fuel into the cylinder...instead, use carb cleaner and spray into throttle body (excess fuel in one cyl will contaminate your engine oil). If it runs normally after you get it started likely the pump is good (unless you have problems at high rpm's under power) Regulator is likely good as well...default is to more fuel not less.
check you throttle position sensor first then fuel pressure regulator, then fuel pump. i have a 92 and had to recently do a massive overhaul. my rough idle was caused by a malfunctioning tps with a small exaust leak causing it to race and an intake manifold gasket. also check your idle speed adjustment settings.
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