So recently i picked up a 95 camaro, ttops 5spd, 3.4. I so far replaced the injectors, ignition moduale, fuel pump and filter, spark plugs and wires, fuel pressure regulator, and about to buy new coils once i get paid. The issue is the cars constantly back firing, smelling like gas, and cant haul ***/move under power, unless the foot is to the floor. I suspect its a leaky injector cause that park i did cheap out on a bit for a amazon set as well as it sounds like when i prime the car/turn the key, the intake is filling with gas and it sounds fuller the more i hot wire the fuel pump prime wire thing under the hood near the pass side fire wall. So my main thing is, how do i test the fuel injectors? I know to undo the bolts and lift it up so the injectors are visible, but is there any tricks or anything cause i cant really get or see the back side of the injectors since ya know the engine is half under the fire wall. So any tips or tricks on that? I also pinched off the fuel return cause when i prime the pump for a split second its at about 45ish then drops to 40-39 then slowly goes down to 35 till i go out an hour later and its below 30, very slow drop after the 35 mark. Anyways i pinched off the fuel return line and it goes to 39-38 and stays there then instantly drops to 35 once i un-pinch it. I looked along the fuel line and dont see any leaks or anything there, so what do i meed to look for in terms of the return line? Also while running the car goes to about 40 and stays there running no matter what, and the fuel pressure regulator does work cause it drastically changes the idle when I unplugged it so i plugged it back in instantly.
I appreciate any help for this

 

Assuming the fuel pump ran for 2-seconds to prime, then shut off - The fuel pressure regulator appears to be leaking, based on the results of pinching the return line (possible to damage the factory nylon line doing that). If pressure holds with the pump off and the return line pinched, the injectors aren’t leaking. A leaking injector will cause the pressure to drop rapidly.

If you want to physically check for leakage, you can pull up the fuel rail with the injectors intact, prime the pump to hold pressure and look for leaks. Put a jar under each injector to see if any fuel is collected. But, my lack of knowledge of the V6 fuel rail setup doesn’t allow me to tell if that is even doable. With the LT1 V8 the rails can easily be lifted completely off the intake manifold and moved out from under the cowl.

Not many people left on this site. Most of us are LT1 owners with limited experience on the 3.4 L V6. What brand and size injectors did you buy? Are they the correct replacement for the V6 engine, specifically the flow rate (#/HR)? I see a lot of counterfeit Bosch injectors on eBay at less than $100 per set. They are Chinese junk. If that's what you bought on Amazon, could be the whole problem - serious mistake. Not necessarily that they’re leaking, but could be unmatched and delivering the wrong amount of fuel. Pull the oil dipstick and see if the oil smells of gasoline.

Hard to construct a situation where the intake manifold could fill up with fuel. The injectors are in the runners to the head, and spray fuel directly at the intake valves. At least one intake valve should be open, preventing fuel from building up in the intake manifold. And that one open valve would fill the cylinder with fuel and hydrolock the engine. Fuel would also be leaking past the piston rings and diluting the oil.

 

I gotcha, I appreciate the response. These 3.4 sucks, i had to dissemble the whole fuel block to remove from the engine cause the regulator and injectors are too big i couldn't squeeze it out, but maybe if i find some house to collect it to a bottle? I just kinda guessed too at the filling the intake so im 100% sure your right about them being at the valves, but it does sound like its filling up that part when i do it. Im not sure if its normal or not as ive never owned a v6 or any chevy like that. It could be the fuel pressure regulator cause imma be honest, i did strip out and break off one bolt holding that down, but i didint see it leaking on the outside so i just said oh well pretty much and left it at that, cause i already replaced the regulator once with what was a ac delco regulator on amazon, but turns out someone has been swapping out those with crappy regulators in the ac delco box to scam and it ruptured instantly. So I'll definitely undo the regulator and fish that bolt, well stud now lol, out and fix that bit. I greatly appreciate your response

oh and heres the link for the injectors i bought
https://a.co/d/dlghvlD
i went throught the reveiws and it seems like they work and all, but now relooking through I probably should of done more research on those before getting, mainly like one with more reviews instead of the 5 it has and if it has actual info

forgot to mention, i did pull the plugs as well and they all did seem dry as well after priming the pump a few times

 

The fuel pressure regulator controls the pressure by closing off the fuel passing to the return line. The regulator has a spring and a diaphragm that opens and closes the orifice in the regulator, based on intake manifold vacuum. The diaphragm can leak, in which case fuel can get into the vacuum compensation line. Check the vacuum line for wet fuel.

Or, the mechanism may be damaged, not be able to fully close off the fuel flowing to the return line. It has to close fully to maintain the pressure when the pump shuts down. That's the failure the pinching the retur;line reveals.

I never heard of Anglewide injectors. But for less than $15 each, they can’t be very good. Their other injectors on Amazon look just like the Chinese crap on eBay at ridiculously low prices. I'm convinced the 5-star reviews on Amazon are mostly fakes. A single genuine GM new injector is going to run $80 and up. And I don't see a lot of name brands available for the 3.4L. Someone might have rebuilt OEM at a reduced price.

 

I gotcha, i think it could be its not closing all the way cause i have pulled that vaccum line as soon as im done running it and its been dry every time, ill pull the fuel rail and fix that broken bolt and see if that helps which i bet it would. Yeaa those injectors probably wernt the best option lol, i still have the previous injectors from when i replaced them so ill send them off to hopefully be rebuilt, they had wayyyyy too much rust on them every where same with the original regulator for me to even think of rebuilding them. But ill try to see if fixing the regulator first will work and then go to the injectors then come back here lol. I greatly appreciate it