FC3S_nataku

iTrader: (3)

as the title implies i need help. i have a 88 T2 and it has hot starting problems and i need a bandaid untill i can save enough for cleaned injectors. can anyone tell me the wire to the fuel pump to cut and put a switch in, thanks

Gabe

FC3S_nataku

iTrader: (3)

help plz

FC3S_nataku

iTrader: (3)

help plz, sunlight running out

Wankels-Revenge

http://www.rotaryresurrection.com/ro.../flooding.html

Its in there somewhere......

FC3S_nataku

iTrader: (3)

damn it, im sorry, im retarded

Wankels-Revenge

its ok...nobodys perfect

tinvestor

Tired of pulling the fuse under the hood?

HAILERS

If you want, just disable the black/blue wire at pin 3B of the ECU. Its the smallest plug. The wire is on the bottom row, far right. Either extract the wire using a small jewlers screwdriver or cut it about six inches back from the plug (so it can be spliced back together if you don't like the results.

Try this method right after you get the car up to full hot. Then drive it for a couple of hours and turn the engine off and back on. I think you'll like the results.

FC3S_nataku

iTrader: (3)

^ what does this do?

HAILERS

Pin 3B is the START signal to the ECU from the start circuit. It's (Start signal) put on that wire as long as the key is held to START. That usually only last a few seconds. After the car starts that wire does nothing in life. When the key is held to START, approx 12v is put on the pin 3B. In real life I've only seen approx 7-9vdc due to votlage drop by the starter.

The car does not use the AFM signal to Start the car. The ECU uses a START MAP for fuel during starts. It looks for the rpms to be under approx 400rpm and uses the water temp sensor signal for the amount on fuel (and don't forget the 12v signal from pin 3B). This results in the car not starting during hot starts because the START MAP is putting too much fuel in the combustion chamber.

IF the wire is cut and the engine is warm, then the ECU does not look at that START FUEL MAP. It never sees the Start signal. So it uses the afm plus the water thermo sensor for fuel . The time in mili seconds the injectors are open during this type of start is much less than the one using what I call the START FUEL MAP.

I'll attach the jpg of the start chart later if I can find it.

https://www.rx7club.com/forum/attach...hmentid=150448

And I have looked at the duration the injectors stay open, with the wire intact and with it disconnected. There is a large difference in the time the injectors stay open,.

NZConvertible

Here's the simple answer. Find the circuit opening relay under the dash beside the steering column. It has a yellow base and white plug:



Cut the black/white wire in the middle labled B. Use wire of at least the same gauge to extend the two cut ends to your switch. Make sire the switch is rated for at least 10A.

FC3S_nataku

iTrader: (3)

^ im confused, by cutting B wouldnt that make the car not have the IG switch unless the switch was one=car wont turn over unless switch is on.

HAILERS

No. It has Zippity Doo DAh to do with the starter turning over. That signal on pin 3B is only to make the ECU go into the START FUEL MAP. You are trying to AVOID the Start Fuel Map.

This 3B signal is just 12v picked off the start wiring to the starter. It has, again, nothing at all to do with the starter turning over. Nadda. I've had this wire out for exteded periods of time with NO problems whatsoever. I take that back. When the outside temps are in the fortys the car is harder to start when stone cold. Once it gets started, then the rest of the day is a walk in the park. A simple switch on wire at pin 3B would avoid even this one event a day problem.

HINT: summers right around the corner. Not going to be in the fortys no mo.

RotaryResurrection

iTrader: (8)

I've worked on some cars that had this mod pre wired up before, and it never seemed to do diddly for a flooding car.

Not saying it can't or won't work for you, you should try it and see what happens, but I don't feel its a substitute for a fuel pump or injector cutoff. An injector cut is the ultimate antiflood device...I've wired that up on a couple of s4 cars before, and it works WELL. But, the wiring is a PIA, sort of hard to access and make it reliable.

beamer242

http://www.cruzinperformance.com/fuelinj.html

it really doesnt cost that much. keep pulling the fuse and save some money and do this.

Brian

FC3S_nataku

iTrader: (3)

^well i used to write up on your page and it works. still it has a lag of like 3 or 4 sec before it starts but it starts.

RotaryResurrection

iTrader: (8)

When will people learn. FLOODING IS NOT ALWAYS THE RESULT OF DIRTY INJECTORS. In fact, more often than not, the injectors arent that dirty, nor do they fix the problem. Flooding is most often the result of marginally low compression, in the 95psi and below threshold. Dude's motor falls into this category because it is a fresh used housing rebuild that (I assume) hasn't yet been broken in. Used housing builds are low compression until they break in fully...they build up as you drive them more. In the meantime they exhibit the same symptoms as a worn old original engine.

beamer242

i understand that, but what i say is if its only costing $12 per injector why not clean them they probably need it. sorry i didnt mean to make is sound like that will for sure fix his problem.

Brian

HAILERS

Fuel cut switches are for sissies.

New 550 can be had cheap for 57.95 all day long.

Getting fuel injectors cleaned is usually done by people who are clueless about why their engine won't start.

I've never seen anywhere on this site or the FC3S site a *Mod* (I detest that term) for disabling the pin 3B on a series four and I doubt RR has either.

RotaryResurrection

iTrader: (8)

Mod is short for modification, is it not? I would define modification as altering, removing, or adding to anything that did not come from the showroom stock using a stock type replacement part (tires, battery, brake pads, etc), would you disagree with that? So altering wires and adding switches is not modification?

I have run upon it 3 or 4 times on FC's I've done installs on...having a toggle switch wired into that pin and extended for driver's access. Believe it or not, doesnt matter to me.

NZConvertible

The B wire is power from the battery via the ignition switch and ENGINE fuse. You could put the switch on the blue/red Fp wire instead if you wanted, it would have exactly the same effect.

As with all electrical mods, even simple ones, you should be referring to the wiring diagrams first so you understand what you're doing. It's a very simple circuit.