I have been having annoying drivability and performance issues with my car. The car only has about 3800 miles since a fresh rebuilt and a camshaft upgrade.
I have replaced both catalytic converters, one of them was severely clogged, thinking that this might be causing my problems, but things persist, and get worst when the engine is hot.
The car does not rev freely under WOT applications, it seems to stumble. If I apply the throttle more lightly, it goes. It also seems to stumble and jerk a little under light throtle applications while driving around in a parking lot in second gear.
The car also has a hard time starting when hot. I sometimes have to press the gas a little bit to keep it from dying.
I tested the fuel injectors today, and they all tested between 14.7 and 15 ohms. Is this normal? The Hynes book says that they should be between 11 and 14 ohms. I am not sure if my injectors are out of speck.
I have not yet tested fuel pressure and fuel pressure decay. I have not gotten a fuel pressure gauge yet. I also have not checked the base timing to see what it is set at.
Does anyone have any suggestions?
I really want to get this thing running well enough so that I can start working on the rest of the car, mainly paint. It also gets terrible fuel economy, only about 11 mpg in the city compared to 14 previously. There are no trouble codes that are stored.
Thanks for all suggestions

 

Those injectors have the proper resistance, but they may still be the problem. How many miles on the car? How big is the cam? Did you have any problems before the rebuild?

 

The car has 126000 miles on it. I did not have these problems prior to the rebuild. The car had plenty of power and revved quite freely, until all of the sudden it developed a knock.
The hard starting was there since I bought the car about a year and a half ago. About 2k miles after the rebuild, the left cat was clogged, and I was getting drivability issues like I do know. I replaced that and things improved. A little while ago, I started getting the same issues, I thought that the right cat was going, and replaced that (couldn't afford to do both at the same time when the first went), but the situation has not improved much.
The cam is a very mild cam. It was recommended to me by the comp cams tech line as a sure to work thing with the speed density computer. It is the comp cams 08-500-8. The specs are as follows: duration at .050 lift is 206 int. 212exh. The valve lift with the factory rocker arms is .480in int, and .488in exh.
The heads were machined by the shop that did the rebuild, to ensure that there was enough clearance. I think that something else is starting to fail. I was told from the previous owner that the fuel pump had been replaced withing the last couple of years. Plugs wires cap and rotor were all done at the time of the rebuild.

 

I had a similar problem after rebuilding my engine last year and it turned out that two of the original Multec injectors went bad. Check the resistance with the injectors cold, and then check them again when the engine is hot. Sometimes they appear good when cold, but are bad when hot. Other than that, all I could think of would be to test the fuel pressure, timing, and make sure there aren't any vacuum leaks. It sounds like the problem is somewhere in the fuel system.

 

I do believe that such maybe the case. I will try to check the injectors hot. Although it wont be easy getting those metal clips off.
I think I may have also narrowed down a very small vacuum leak. It seems to be coming from the long hose that goes all the way around to the washer fluid pump. It seems to be quite deteriorated. I will replace it and see what that does.
Thanks for the suggestions.