Guest Anonymous Posted November 27, 2002 Share Posted November 27, 2002 Okay, I finished installing my injectors. The car runs better with the new ones in, revs better than before too. However, it doesn't rev like it should. Sometimes when I step on the gas I get this popping sound from out of the hood, and the revs don't rev fast and they rev in weird staged intervals. Is there a specific way that the wires connect to the injector connectors? Or does it matter? Quote Link to comment Share on other sites More sharing options...
David K Posted November 27, 2002 Share Posted November 27, 2002 The popping under the hood is a backfire through the intake. I know that much at least. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 27, 2002 Share Posted November 27, 2002 Okay, I went out and inspected it further. When I press the gas it bogs down and won't rev, and there is a hollow popping sound coming from the front of the engine, possibly cylinder #1? What does this sound like to you? The engine has 80,000 miles on it and I'm stumped. When I bought the car he said it was the injectors but now they're replaced and it's still doing it. It was revving fine for a little bit, after I first put them in, I even took it out for a spin. But now it's doing the same bog down pop thing again. Could fouled plugs cause this? I'm stumped. Chris Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 27, 2002 Share Posted November 27, 2002 Could it be the fuel filter or the fuel pump? Quote Link to comment Share on other sites More sharing options...
David K Posted November 27, 2002 Share Posted November 27, 2002 yeah i read the post before the last and im thinking the fuel pump is dead. it supplies enough fuel to keep the car at idle, but when you want the engine speed to increase, which in turn demands the injectors fire more, which in turn is demand for more fuel, it will cut out and bog down under a lean condition. I sure its the fuel pump, i have went through this a few times on my Z's. When you change a fuel pump, you should also change the fuel filter with it. Good luck. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 27, 2002 Share Posted November 27, 2002 Is the fuel pump in the gas tank on a 78 280z? Quote Link to comment Share on other sites More sharing options...
David K Posted November 27, 2002 Share Posted November 27, 2002 no, all fuel pumps used in z's are external right outside of the tank and are very easy to change. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 27, 2002 Share Posted November 27, 2002 Is there an easy way to test the fuel pump without a fuel pressure gauge? So far I've replaced the injectors (that's what the person who sold it to me said it was) and the fuel filter. Could it be the fuel pressure regulator causing the bog down? Chris Quote Link to comment Share on other sites More sharing options...
David K Posted November 28, 2002 Share Posted November 28, 2002 no, because ive had mine unplugged from vacumm for a while when i was having engine problems with my last engine. it didnt effect anything having to do with driveability. Its your fuel pump, more than 80% sure. slightly pinch the incoming fuel hose right after the fuel filter with a pair of pliers with a cloth and see if that shuts down the engine at idle. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 28, 2002 Share Posted November 28, 2002 Okay, I pinched the line after the fuel filter with a pair of pliers and it shut the engine off after about 8-10 seconds. What does that mean? Chris Quote Link to comment Share on other sites More sharing options...
jeffp Posted November 28, 2002 Share Posted November 28, 2002 what you need to do is get a fuel pressure gauge and take the quess work out of the troubleshooting. You can get one at Kragen for about 29.00 out the door. If you really think it is the fuel pump, what you swhould have done is pinch off the return line(but not all the way) and rev the engione and see if it improves. That will force the fuel pressure up and make the injectors provide more fuel. Also what you can try, is after you start the car, disconnect the cylinder head temp sensor, and that will increase the duty cycle to the injectors and it should run better. I would really encourage you to get the fuel pressure gauge tho as that will give you a very good indication of a feul or an electrical or finally a mechanical problem.This stuff really is not to hard, but you do need some of the right tools like the fuel pressure gauge to effectively trouble shoot the car. Just my O2 here. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 28, 2002 Share Posted November 28, 2002 Have been thinking about the problem, it may be the AFM. I'm going to check for leaks and such things tommorow. Chris Quote Link to comment Share on other sites More sharing options...
Guest Synthetic Posted May 13, 2005 Share Posted May 13, 2005 Post Up and let us know what you find I have the same problem with an 83 280zxt if I put any type of pressure on the throttle it will stutter and barley manage to rev up meanwhile backfiring on throttle release around 2000-4000rpm. Any thoughts on that? and my next question would be how do I check the timing? I have no markings to go by and my manual says for 82s to be taken to a dealer for timing and 83s are not even talked about????? Quote Link to comment Share on other sites More sharing options...
Guest DoTheDrew888 Posted May 14, 2005 Share Posted May 14, 2005 Your valves are out of adjustment. That would be my guess atleast. I had the same problem so I adjusted my valves and it stopped. Also, there is a mark on the crank pulley and a little plate bolted to the front cover that are used to adjust timing. Quote Link to comment Share on other sites More sharing options...
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