2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

fuel priming switch?

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Old Aug 20, 2008 | 08:35 PM
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rx7convert22's Avatar
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fuel priming switch?

My car is constantly flooding. I have already gone through the pain of getting the injectors serviced and still no luck. I at this point am at a loss of what to try next. I don't feel it is compression since when I do get the car started she runs fairly strong.

Whatever the case I am going to do the fuel cutoff band aid. I know this isn't the best solution but I drive the car like once a week so not a big deal to me. I did a test by pulling the fuel pump plug and sure enough she didn't flood, but since there is no pressure in the system it takes a bit longer (roughly 5 secs) to turn over. This seems like it will be rough on my starter.

I know you can prime the fuel system by putting a wire into the yellow jumper under the hood which causes the car to start a lot easier (<2 secs), but I don't feel like having to go under the hood each time I want to start the car.

My question is would it work to just rig a switch the the jumper? Basically two wires one on each side of the jumper connected to a switch that I run into the car. I then before starting it could fiip the switch on, prime the system then flip it off.

Thoughts? I know many will say just fix the car correctly, but at this point I am set on this kludge.
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Old Aug 20, 2008 | 08:55 PM
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island-fc's Avatar
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just splice a switch on your injector fuse under the hood. every time you start the car you can shut the switch off then turn it on when the car starts. its also a good anti theft device
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Old Aug 20, 2008 | 08:57 PM
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When I pulled that fuse instead the car still flooded. I am guessing this is since the pressure in the fuel system was still present.
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Old Aug 20, 2008 | 08:58 PM
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Going to START with the key does the same thing as jumpering the fuel pump check connector. As long as the key is HELD to START, the fuel pump runs.

Once upon a time.............I had a fuel pressure gauge connected to the fuel lines. I has the engine running and killed the engine using a fuel cut switch. The way I killed it was to rev the engine to three grand and then, simutanously (sp) floored the pedal and flipped the cut switch to OFF.

What that accomplished was to fully deplete all the fuel pressure in the fuel rails. So now there was no pressure in the rails. So, while watching the fuel pressure gauge, I started the engine. The pressure was at full pressure well under two seconds. That's my story and I'm sticking with it.

Just a FYI post.

When you go to START you pull in the Circuit Opening Relay that controls the fuel pump. When you jumper the fuel pump check connector, you put a gnd on the Circuit Opening Relays coil and pull the relay in to run the fuel pump. So you see, one is the same as the other. Both pull in the circuit opening relay.
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Old Aug 20, 2008 | 09:00 PM
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you pull the fuse when you starting the car not when its off, right?
then once its going you put it back in
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Old Aug 20, 2008 | 09:04 PM
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On a series five car, to deflood, all you have to do is HOLD THE PEDAL TO THE FLOOR WHILE CRANKING. It is written.

When you hold the pedal to the floor, the ECU sees the start signal from the key being held to Start, and ALSO sees the TPS wide open, so it cuts the fuel injectors from delivering fuel BUT it allows SPARK to help clear the flooding condition.

That's for a series five only or a series four with a RTEK 2.1.

There's no reason to pull the EGI fuse on a series five car nor any reason for a fuel cut switch. It's already built in the system as described above.

The only exception is if the start circuit has been bypassed for unknown reasons and the ECU never sees the START signal. Just in case: the ECU has zip to do with the starter itself, it just has to see that 12vddc from the start circuit so it has a clue that your starting the car. It's just a heads up for the ECU.
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Old Aug 20, 2008 | 09:10 PM
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ohh s5... lol
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Old Aug 20, 2008 | 10:32 PM
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I thought the ecu sees about 10 volts on pin 3b?
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Old Aug 22, 2008 | 01:20 PM
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From: FORT WORTH, TEXAS,USA
Originally Posted by ITSWILL
I thought the ecu sees about 10 volts on pin 3b?

Well, when the starter is being turned over there will be a voltage drop from batt voltgage, down to ???? 9cdc or so. Much as what you see on the volt gauge in the cluster. I should have said approx 12vdc or approx 9vdc plus or minus a couple.
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