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Car dies at 1500rpms

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Old 10-12-11, 11:01 PM
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Maybe you overlooked it as you must have some type of ground or the car would never run. If you look at the smallest plug of the ECU you will find three wires which are solid Black. These are most of the ECU grounds. If you measure the voltage of these grounds w/key to on they should have zero voltage.

Pic of engine ground.

Old 10-13-11, 11:43 AM
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ok, ill take a look. I dont think ive seen that ground because when I originally dropped my engine in I think I relocated that ground because the engine had been painted. But ill take a look and let you know. I was reading a thread you had going with some other kid. Kinda the same issue.


https://www.rx7club.com/new-member-rx-7-technical-256/injectors-not-getting-voltage-pulse-ecu-964669/page2/
Old 10-13-11, 12:19 PM
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Just a thought, have you checked the fuel pressure in the line? It should be like 60 - 80 psi I think. If not that, maybe check to see if your cat is clogged up. I've seen clogged cats cause cars (even Rotary's) to run like that.
Old 10-13-11, 12:48 PM
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Originally Posted by heyman1104
Just a thought, have you checked the fuel pressure in the line? It should be like 60 - 80 psi I think. If not that, maybe check to see if your cat is clogged up. I've seen clogged cats cause cars (even Rotary's) to run like that.
I havent checked the fuel pressure. I dont have a tool to check it. And I have no CAT, all emissions extras have been deleted. I'm running a 3"DP 3"Mid pipe full Corksport exhaust. I think 60-80 is N/a I believe TII is 75-90 if I'm correct. Do you know what tool I have to use to check it? I'm guessing one with a T fitting.
Old 10-13-11, 01:41 PM
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Nvm i found it online, ill prob order it
Old 10-13-11, 01:53 PM
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pressure is ~40psi with the regulator open to atmosphere and 32-34psi when idling. static pressure from the pump with the return line blocked is supposed to be about 90psi.
Old 10-13-11, 10:39 PM
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Originally Posted by Karack
pressure is ~40psi with the regulator open to atmosphere and 32-34psi when idling. static pressure from the pump with the return line blocked is supposed to be about 90psi.
????????
Old 10-13-11, 10:50 PM
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The fuel pressure at idle is a wee bit above 30psi and upwards of 40 psi when the FPR has no vacuum which is the same thing if the vacuum hose is pulled off of the FPR. The FPR has no vacuum under certain situations like starting the car for example. If you test for fuel pressure before the fuel filter and the fuel line ran directly into the fuel pressure device it would measure up to 90 psi. The other numbers are when measured "after" the fuel filter using the hose that goes into the engine or the one coming out and the return line (coming out) is the better of the two places to measure the pressure. Teeing in the device is the method used.
Old 10-13-11, 11:33 PM
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oo ok liike this then

http://www.rx7.org/Robinette/fuelp_gauge.htm
Old 10-14-11, 12:15 AM
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Pretty much.
Old 10-14-11, 11:15 AM
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Originally Posted by zoneman2
Nvm i found it online, ill prob order it
AutoZone or some place like that might have one that you can borrow. No sense in buying if you can just borrow it.
Old 10-14-11, 11:45 AM
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how about if your trying to crank it? And my injectors still dont work... I glues them back into the connectors... and still nothing and I tested them they get a 11.9v at on, but i wasnt able to check the crank
Old 10-14-11, 11:53 AM
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Which injectors are you testing as the engine is turned over, primary or secondary?

And why did you glue the injectors back in to the plugs for? What if they need to be removed? If you did as suggested in post #21 you could have easily verified whether the injectors were properly seated in the plug.
Old 10-14-11, 12:09 PM
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Originally Posted by satch
Which injectors are you testing as the engine is turned over, primary or secondary?

And why did you glue the injectors back in to the plugs for? What if they need to be removed? If you did as suggested in post #21 you could have easily verified whether the injectors were properly seated in the plug.


no I ment the wire back into the clips. because the wires were falling out. and I'm testing primary, but nothing is comming out. But I have the CAS inplugged.
Old 10-14-11, 12:10 PM
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Originally Posted by heyman1104
AutoZone or some place like that might have one that you can borrow. No sense in buying if you can just borrow it.
It was 28$ and i bought the gauge and the fitting to always monitor the fuel pressure.
Old 10-14-11, 12:14 PM
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Originally Posted by zoneman2
no I ment the wire back into the clips. because the wires were falling out. and I'm testing primary, but nothing is comming out. But I have the CAS inplugged.
Are you expecting the injectors to work w/o the CAS being plugged in? They won't.
Old 10-14-11, 12:46 PM
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oo i never knew that...... damit. well i feel dumb know.. Que Epic fail post
Old 10-14-11, 12:53 PM
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The CAS provides a signal for the ECU and w/o it the injectors and coils will not fire.
Old 10-14-11, 02:18 PM
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Is there a way to make it so the coils wont fire? I really dont want a spark with gas fumes
Old 10-14-11, 02:30 PM
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Never mind..
Old 10-14-11, 04:03 PM
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Originally Posted by zoneman2
Is there a way to make it so the coils wont fire? I really dont want a spark with gas fumes
Disconnect the electrical plugs to them (not spark plug wires but the other wires). Leading has the White two wire plug and the trailing has two plugs.
Old 10-14-11, 10:28 PM
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Originally Posted by satch
Disconnect the electrical plugs to them (not spark plug wires but the other wires). Leading has the White two wire plug and the trailing has two plugs.
ok thanks. I'll let u know how it goes 2morrow.
Old 10-17-11, 11:27 PM
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Injectors sprayed normal and fuel pressure was at 40-45psi at crank. The only thing i can think of that the car ran on 1 rotor was a massive vacuum leak or it was because my oil was soo fouled with gas that it wasn't igniting right, or my coils are bad. Satch or Karack any ideas?
Old 10-18-11, 10:13 AM
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double check all your spark plugs to be sure they are firing, even if they are 100% new.
Old 10-18-11, 10:28 AM
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how would I safely do that? since there is the smell of fuel in my system and my fuel pressure gauge leaks the smallest amount of fuel, like a half drip ever 5-10 mins. It just needs to be tightened more.


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