I've been trying to figure out a fuel problem with my car for the last two weeks, the car had started missing in the upper rpm range (5-6K) for a week and now just this weekend it started missing all over the place, running horribly, felt like it was going to die at times while driving. I have changed the fuel filter and no difference, and I can hear the fuel pump running. I just got a fuel pressure gauge last night and checked the pressure with just the key on and it was at 42 psi which was in the normal range according to the Haynes manual so I think the pump is ok. Then it said to check it after starting the engine, it barely moved, only dropped to 41. The manual says that it should drop 3-10 psi. I don't see any vacuum leaks in the line to the regulator or any other vacuum leaks so I assume the requlator is causing this problem. Could too much fuel pressure from a bad regulator be making my car run too rich and making it miss and carry on this bad? Also it did not mention it but can the stock regulator be cleaned or should I just replace it? Thanks.

 

Hate to say the swear word, but it may be you ropti. Mine was cutting out real bad at WOT for about a week. Then it just seemec to not want to run at all. Changed the opti, and cam, everthing was fine after that.

 

The reason I suspected the fuel system first was that all these problems started right after running the tank pretty low then adding a couple gallons of gas with ethanol (which I'd never used, apparantly it is a good fuel system cleaner, maybe too good in my case) Anyway, since the fuel pressure hardly budged when I started the car I'm thinking it's a bad regulator. I'll probably just replace that first, just wanted to make sure this was the problem before replacing something that can be fixed or that I don't need to.

 

Maybe with all that cleaner, some trash came loose and plugged or interfeared with the diaphram in the regulator somehow??????

 

That's what I'm thinking may have happened. I think I'll try taking it off and cleaning it out , if that's possible, and see what that does. I thought more people would have had experience with this problem, guess I'll try to figure it out myself.