I have a 91 355 TPI and the exhaust has a popping sound in it. I wanted to know if a leaky injector will do it. Also on all of our fuel rails there are four screws holding it down, well on mine its missing one. Will that effect the injectors in any way? The reason I suspect injector problems is because I disconnect a plug cable and it will studer, but if I disconnect an injector the popping will go lower but wont studer much. I checked the fuel pressure and with key only it read 45PSI with the car on it read 37-38PSI, and a quick rev will go up to 45 and down. any help appreciated, Thanks

 

ANYONE? I am really tired of that sound.

 

There are lean pops and rich pops. How's it smell? Could even be just the exhaust. How long does your pressure hold? You could also ohm your injectors.
Now, put that bolt in that you're missing. Besides a major safety issue, fuel coming out and hitting a hot manifold, you could have an air leak.

 

While I agree that you should put the 4th bolt into the rail, in reality, if the other 3 bolts are tight, that rail isn't going to be an issue. Those things are rigid enough that one tight bolt will prevent the opposite side of the rail from lifting up at all, which means that the injector o-ring seal has a long way to go before it leaves the manifold bore.

i don't think a leaky injector will cause this sort of a problem. An injector that's stuck open may, or you could have an exhaust leak that's letting oxygen get into the exhaust and causing the unburnt fuels to ignite.

 

Oh so I might have a exhaust leak huh? Well gotta go check on that now thanks. Oh and the exhaust smells good well not really but normal and what do you mean how long does the pressure hold? with the car on or off? I already did check the ohms on the injectors, they were all the same.

 

The rail really isn't rigid at all. It's only held together with clamps around o-rings.
For the cheap insurance that a bolt would cost, it's well worth it for safeties sake.