experts only
experts only
my 88 rx7 wont stay running. I can put some starter fluid in the throttle body and it starts and rives up to 4000. I replaced the fuel pump and fuel filter when it runs seems like its burning gas. It will only run for 5 seconds or so before it stops. When I run fuel pump directly to the battery I can here it when its connected regularly I cant here any noise out of fuel pump.
I don't know what to do next. I cant see any problems with vacuum lines. or any blown fuses.
SOME ONE HELP ME
I don't know what to do next. I cant see any problems with vacuum lines. or any blown fuses.
SOME ONE HELP ME
On the 86-88 cars two of the wires for the mechanical air meter are for the fuel pump switch. If the afm isnt connected or is bad the pump wont turn on. Just turning the key to on isnt going to prime the system like you expect in newer cars, the engine has to be pulling enough vacuum to moved the flapper door.
Joined: Aug 2002
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From: Freeland, MI
experts only
On the 86-88 cars two of the wires for the mechanical air meter are for the fuel pump switch. If the afm isnt connected or is bad the pump wont turn on. Just turning the key to on isnt going to prime the system like you expect in newer cars, the engine has to be pulling enough vacuum to moved the flapper door.
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Your title said experts only, so I didn't chime in earlier, since I don't consider myself one. I noticed satch and others that do know their **** didn't either. It may have been a bad choice of words lol. Anyway, just saying so u don't turn members away.
Let's start by checking the fuel pump control system...this is only the first part:
Do you know the yellow fuel pump check connector? Google or advance search the forum "pictures sensors for reference" with my name. One of the pics shows it. It's near the AFM. A yellow plug usually surrounded by a black rubber boot in a nearby harness. We'll come back to this plug in a minute...To clarify and correct some info, the pump turns on when cranking via a start signal from the starting circuit via the circuit opening relay. When the engine pulls enough vacuum, the flapper in the AFM moves and closes the fuel pump switch inside it, to keep the fuel pump on. So the pump runs (1) when cranking or (2) the afm fuel pump switch is closed (engine running keeping afm flap open). When either of these happen, the "circuit opening relay" under the dash activates and turns on the pump. This is also a safety because it ensures the fuel pump shuts off if the engine turns off, even with the ignition on. What the yellow fuel pump check connector does, is it bypasses the two, in a way, and activates the relay.
So try this: With ignition on, find the yellow fuel pump check connector and jumper it. The relay under the dash should immediately click, you should hear the fuel pump run, and soon after fuel rushing through the fuel rail. If this happens, now try starting it and see if it stays running. Whether yes or not, we'll go from there.
If I forget to come back to the thread, you can pm me, but there are other very knowledgeable folks that can take you further.
Edit: post #3, pic #5 https://www.rx7club.com/2nd-generati...erence-671004/
Let's start by checking the fuel pump control system...this is only the first part:
Do you know the yellow fuel pump check connector? Google or advance search the forum "pictures sensors for reference" with my name. One of the pics shows it. It's near the AFM. A yellow plug usually surrounded by a black rubber boot in a nearby harness. We'll come back to this plug in a minute...To clarify and correct some info, the pump turns on when cranking via a start signal from the starting circuit via the circuit opening relay. When the engine pulls enough vacuum, the flapper in the AFM moves and closes the fuel pump switch inside it, to keep the fuel pump on. So the pump runs (1) when cranking or (2) the afm fuel pump switch is closed (engine running keeping afm flap open). When either of these happen, the "circuit opening relay" under the dash activates and turns on the pump. This is also a safety because it ensures the fuel pump shuts off if the engine turns off, even with the ignition on. What the yellow fuel pump check connector does, is it bypasses the two, in a way, and activates the relay.
So try this: With ignition on, find the yellow fuel pump check connector and jumper it. The relay under the dash should immediately click, you should hear the fuel pump run, and soon after fuel rushing through the fuel rail. If this happens, now try starting it and see if it stays running. Whether yes or not, we'll go from there.
If I forget to come back to the thread, you can pm me, but there are other very knowledgeable folks that can take you further.
Edit: post #3, pic #5 https://www.rx7club.com/2nd-generati...erence-671004/
Last edited by pfsantos; Jun 3, 2015 at 07:44 AM.
Do you still have the problem when the fuel pump is connected directly to the batt(always on)?
Check your injectors. I had this problem recently and faulty injectors was the culprit.
Check your injectors. I had this problem recently and faulty injectors was the culprit.
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Daua118
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