As we have said, we’ve had good and bad experiences with this type of sealer. We’ve had it work perfectly in an inlet port like yours. Then we had another set of heads that were leaking in the rocker arm area. The sealer worked for the first couple of rebuilds (this was our 700hp dyno engine). After the heads were removed and installed several times, the persistent leaks began to reappear. We blamed it on the re-torquing of the cylinder heads and opening up new porous openings in the casting.
You’ll need to make the call. New heads would surely take care of the problem. However, for your application, your repaired cylinder head may be just fine. Hope this gives you a little peace of mind.
My ’95 Chevy Camaro Z28 has a 383 stroker, a racing 4L60E transmission, a six-point rollcage, and true dual exhaust. The problem is that the engine will not fire most of the time until the third hit of the key; when I go to start it, if it doesn’t fire the first time I let go of the key. I don’t just sit there and crank on the engine so I don’t burn up the starter. The engine is turning over; it just won’t fire. It has been doing this for about three years now. I can hear the fuel pump kick on every time. Sometimes it will fire up on the first or the second turn of the key, but usually it’s the third turn. I have replaced the carbon can, the check valve for the carbon can, the TPS sensor, and the fuel pressure regulator. I think that’s about it. When I first built the engine it would fire up right away, just barely had to touch the key and it would fire. However, it still had the stock injectors and stock fuel pressure regulator. I’m just wondering if that could be the problem. I have sprayed starting fluid into the throttle body. It would fire up, then burn all the starting fluid off and die. Then I would go to start the car again and it would fire and run fine. So I do know it is a fuel problem. But I would think if it was a fuel pump it would have gone out by now or the problem would get worse. But it’s not. The problem is staying the same. Please help!
The first thing you need to do is install a fuel pressure test gauge on the test port on the fuel rail. This will give you insight into what is happening with your fuel pressure. As you stated, you can hear the pump cycle when you turn on the key. But is the pump running when you crank the engine? Also, when the pump cycles with the key in the run position, does the fuel rail hold fuel pressure? If it doesn’t hold pressure right after the pump shuts off, the check valve is bad in the pump. If that is the case, and the pump isn’t firing off when the engine cranks, it’s not going to start.
One thing that bothers us is that you said that it would fire right off with starting fluid; however, the engine stalled after the starting fluid had burned up. The fuel pump should have been running once it fired on the starting fluid. An oil pressure switch controls the fuel pump relay. This switch closes at 4 psi of oil pressure. Your fuel pump should have been singing when it was running on the starting fluid. The only way you’re going to track this down is with a fuel pressure gauge. Get some help from one of your friends so one can be behind the wheel while the other watches the gauge. Always be safe.