OK13B

iTrader: (3)

well it's been a few months.
I'v been working on it when i could. I still cant get her to start. I have done all that I can think of. I'm convinced it's something to do with my fuel. it's not timing right, or something. so I'm looking at putting a carb on it. I used to cring at the idea of putting a carb on my 13b, but with all the problems i'm having it seems like a simple fix. a Carb is, for the most part, a stand alone fuel system, right?

The reason im looking at putting a carb on is simple. I have spark perfectly timed with the engine, i have checked this 100 times over and over, but there is no way to time the injectors, it is timed off of the spark timing and air flow combined through the ECU, Correct? so as i see it if i put a carb on her then that will fix all my fuel issues. sure I could put her in a shop, HA! or replace my ECU and engine wiring, but that just doesn't seem like it would be very cheap. mide you im sure going to a carb wont be cheap either, but in the long run it'll be more simple to tune and all that fun stuff, sooooo my main question is.......

is there a "poor Mans" (something i can part together) way to put a nikki carb on my 6 port 13b? or am i looking at having to buy the whole kit from mazda trix or atkins?

RX-7 Chris

iTrader: (19)

if your problem is the timing, a carb isn't going to help at all.

Sometimes the best way to go through the system is to start at the beginning of the list. Check over everything including the fuses.

andernamen

iTrader: (2)

I think there is a thread in the FAQ's about timing. On the flywheel there is a cut out. When this cut out is even with the intake/exhaust side of the engine, you are at TDC. The marks on your e-shaft pulley ought to line up or be pretty close. I think there is a mark on the distributor as well. If you can get it close enough to run, you should be able to put a timing light on it and get it exact.

RX-7 Chris

iTrader: (19)

you are right.

OK13B

iTrader: (3)

I've put a timing light on it just turning it over with the key and it's timed right on with the leading and trailing. what I'm talking about if the fuel timing is off. since the fuel is directly injected into the combustion chamber, so if the timing of the fuel is somehow off it wouldn't be able to start due to the fact that there would be to little fuel or none at all. So my question is.

How are the fuel injectors timed?

and yes i'm getting fuel, I Have pulled my injectors and cranked te engine, fuel is coming out.

OK13B

iTrader: (3)

Well a lot has happened since I last posted. I chucked going FI. I order the RB 6 port intake for a holly, then got an edelbrock 1405 (600cfm). Made all my own linkage and brackets for the return spring, the cable holder and when the cable connects to it. I know there are kits but I wanted to try to make it all first. Which worked well.

For the return spring and accelerator cable holder I used what was the piece that held the intake up. (See pictures) I bolted right to the top of the engine I pinched one half so the spring wouldn't jump out when letting off. And had to expend the other side to hold the cable. Haven't had a problem in the 3 months I've been driving her every day.

For where the accelerator cable connects to the carb I took just the part that the end of the cable connected to, and I mean the very end of the linkage. Drilled a very small hole in it and got a small stainless screw just bigger than the hole. I got a bolt that fit the screw and put in on the other side of the carb linkage and screwed it together. now it doesn't look perfect but I haven't had a single issue with it.

Next was the fuel pump. The stock one obviously wouldn't work now that its carbureted. So I got a carter P4070 (4-6 psi) that was an easy mount. I put it right under the driver side bin. Connected it all to the preexisting electrical system. I also used the old fuel shield as a backup plate inside the bin. Better safe then sorry right.... ( there is more to the fuel pump in a minute but I'll get there)

Next I didn't want to use the old very small fuel lines so I ordered 3/8 fuel line hose 25' of it. better to have to much than too little. Cut to size and ran right under the car using zip ties. I do know the risk in using hose and not steel tubing under the car but I don't think I will have a problem with it. I have no slack under the car.

then I got the new 3 row aluminum radiator in, and e fans. 2 1500 cfms one push one pull on a auto turn on switch, easy enough. Only reason I have a push and a pull is they wouldn't both fit on one side. All I had to do was pull one of them apart turn the blade around and refers the positive and negative. Works perfect though I think it stays too cool. That's in part to the fan switch being at 180 non adjustable... That's going to have to change...

So I go to start and after a little timing issue she started right up, for about 5 minutes and dies. crank her over again, same thing. Hmmm. continues on like this for awhile. I checked everything. Had a see through fuel filter under the hood and I could see fuel in it. Surly it wasn't a fuel issue, right? So one day I thought well I'll drive around the neighborhood. I could go for about 5 min then died. Well so I got the idea to look at the engine while I was cranking her over. I noticed an extreme amount if fuel going through the filter. It hit me. next test. Start the car and disconnect the fuel line. Sounds like a bad idea I know but it was the only way I could do it. So car started disconnect fuel pump and... No fuel

the car would only pump while cranking her over. not wanting to redo all that electrical work I ran new wires 12 gauge. With a 30 amp resistor and a 12v relay to a switch. very easy and now I have a fuel cut of switch for safty and good luck stealing my car, you'll only get a few blocks. Lol! I turned that silly radio thing on the center console into a switch to my fuel pump.

Cars been running and driving great for 3 months now. I have had a few small things pop up. One point if I turned her off and took the key out She would stay runing. I guess there is a relay under the hood that if its not up and down the car will stay running. Weird. Haven't had an issue since I put it where it was meant to be. Here pix and all the work

OK13B

iTrader: (3)

More pix






















There is still lots of work to do, header, suspension and then interior and exterior.

jeremyferguson4444

iTrader: (6)

Looks good! How do you feel about the driveability differences between the old FI and new carb?

Just curious, was that the problem the whole time (last year) when you couldn't get it started....the no power to the fuel pump?....or was that a new problem with the switch over to the new low pressure fuel pump. Sorry if I missed that in the thread.

OK13B

iTrader: (3)

I suppose it could have been a contributor to the no start problem. Though even with that it should have turned over and fired up cause it would pump when I was cranking. Though I Did take over half the wiring for the ecu when I switched over so I most likely justed pulled a wire that kept the pump going after cranking it.

Driveability isn't bad. I have noticed on sharp corners there is a cut out though I haven't really tried gassing it after/during a corner. there is also a little decrease in throttle response. If I hammer it, it'll take a second to go. it's like it cuts out for a second then the fuel and air hit the spark and boom, gone. I probably need to increase my spark to handle all the extra fuel and air.

NCross

iTrader: (18)

The stutter is probably because the 600cfm carb is too big. Especially if your still using the stock exhaust. I would also put the radiator metal cover back on so it doesn't over heat.

OK13B

iTrader: (3)

Exhaust Is just 2 1/2in tube all the way back though I do have the stock manifold on right new. as for the over heating I haven't had any issues at all. It actually stays to cool, after 4 hours of non stop driving with it 98° outside it I saw the highest temp the car has gotten since the rebuild see pic




I actually thought my thermostat was broken as it never really warmed up. One day I disconnected my e fans and sat at an idle till o saw it start going up. I even replaced the sensor and it didn't make a difference. I don't have that cover anymore, I actually plan on leaning my radiator forward soon. Then eventually get an extra hood and do something like this



Though I need an extra hood before I start that...