Raymr

Has anyone had noisy, clicking fuel injectors, and if so, what did you do to fix them?? My rebuilt motor is making a tapping noise that I think is coming from that area.

Project84

Is this the first time you started up and run the rebuilt motor? If so, check the timing. How close do you have to be to hear it? Does the car run ok, or does it run like a bag of hammers? Check spark plug wires and make sure one hasn't fallen off and is arching on something else.

Raymr

It started making the noise right away upon startup. It was running rough and I had a hard time getting it started at first, which I think is the case with all fresh rebuilds. It's been running for about 3 hours total now and it's smoother & responds well to throttle.

The tapping noise sounds similar to a lifter noise in a piston engine, ie it's hard to pinpoint the exact source, since it echos through the block. Best I can tell, the sound is coming from the primary injector area. I used a length of vaccuum hose to listen around, and thats where the noise is most distinct . It's loud enough to hear inside the car.

Project84

I doubt its an injector making that kind of noise. Is the motor completely stock? What kinda mods you got?

Raymr

It's completely stock '88 n/a 5-speed with a Bonez cat. I'm told the noise can't be internal unless the bearings inside are shot.

Project84

Its kind of a bitch to get to the injectors with all the emissions crap on the motor, if you want to see if its the injectors, swap the two primary injectors with the secondary injectors. Other than that, you gotta check all the little nit-noid valves, vaccuum operated solenoids, and those sort of things.

The only internal moving parts are the rotors and shaft, so it is correct that a bearing would probably be the only thing internal to make noise, but it could also be the oil pump, but other have described it a lot different than what you are saying. An apex seal side piece may have come off, or something metallic may be inside with the rotor. Those may be extreme scenerios so start with the simplest thing first.

Raymr

I'm gonna take the upper intake parts off again and recheck everything. If an apex seal piece came off, wouldnt there be a change in compression? When I took the plugs out to crank it, the puffs sounded steady and all the same, but I didnt do a real compression test.

Raymr

Well I swapped the primary injectors with the secondaries, and I double-checked for any loose hoses, loose EGR, brackets, etc. THe noise is still there and hasn't changed. I also ruled out the ACV by making a temporary gasket for it without any holes. I also looked with the lights out to see if a spark was jumping across anywhere - none. Are there any other ideas on what to check? I'm pretty much at a loss.