I have a 88 Camaro which started to run rough for no reason last night. Irregardless of the RPM range, it runs just as poorly. My initial thought was that I blew a valve but I ran a compression test on it and all cylinders were ok. However, I noticed that the back plugs were running rich.

I tested the fuel injectors with a volt/ohm meter and all of them had 16.3 ohms. Then I pulled the fuel rail and the injectors all looked fine (ie...no cracked or burned tips). FYI, all the injectors only have 48K miles on them.

I am begining to think that the problem is fuel system related since the plugs are not all the same color. Also, the plugs closest to the point on the fuel rail where the gasoline enters the fuel rail seem to be running the richest. Could I have a fuel pressure regulator problem? Also, since I have the fuel rail out can the injectors and the fuel pressure regulator be 'bench tested'?

Thanks

 

How is the ignition system? Also, did the distributor bolt come loose? It may sound weird, but they can loosen over time and the distributor can move a little. I would check that stuff out. Sounds more like an ignition problem somewhere. Coil, plugs, rotor/cap, and maybe a off timing distributor. *shrug*


-Dan

 

Bleh, I mean, the distributor could be off on timing a bit. Heheh, I really should read my stuff before I send it.

-Dan

 

Welcome to the boards!

The only real bench testing you could do with the rail popped out would be a leak test... pressurize the fuel system by turning the key to "on" (without cranking, and make sure the engine's cold, and you're not smoking or otherwise playing with matches ) and see if any injectors drip.

If you have a fuel injection tester, you could also pulse each injector to check the spray pattern- if you like fuel spraying all over the place.

The same fuel injection tester would allow you to perform an injector balance test- but that would be done with the rail installed to the car.

Most of your testing (including the balance test) can be done with a fuel pressure gauge. You'd want the $40 one meant for port fuel injection- it goes up to around 80 PSI. The cheaper carbureted ones won't work; they're low pressure.

I would do a major tuneup first- or at least, if you think you've done a full tuneup, look at the list, and cross off what you've done. <a href="https://www.thirdgen.org/techbb2/showthread.php?s=&threadid=162251" target="_newwin">Click here to read the major tuneup information!</a>