too much fuel
 

Have not been her for a while , however need some help
my 85 GSLSE is sending too much fuel causing the plugs to be soaked.
It wont start.
with so many things to check dont know where to start.

I crank the car with the plugs out and there is too much fuel going into the chamber. I plan to follow the this link thinking I also have slow PW and suspect of low voltage.

http://www.nellump.net/peri/epi/firs...inkRepair.html

how ever have not found a troubleshooting for excessive fuel :dunno:

typical when I have not started the car for a while.

have consider leaking injectors is ther a less expensive cost than Mazdatrix?

at this point replacing all injectors and other EFI parts will cost more than a Holley set up.

would like to keep it original but just dont know



any help will be greatly appreciated

Injectors rarely need replaced, they do require an occasional cleaning. You can send them out to R C Engineering, Witchhunter or Cruiz Performance for service and cleaning. Prices range from 15-25/injector. I've run across one SE injector that had a cracked body, all the the other injectors have come back in like new condition. I do have a a single spare SE injector if anybody needs one.

If you don't have a copy of the FSM, download it from either of the following sites.

http://foxed.ca/foxed/index.php?page=rx7manual

http://www.wankel.net/~krwright/cars/rx7/manuals.html

Anytime you get flooding on an SE, suspect the Intake Air Temperature sensors - there are 2 of them. One is located inside the AFM behind the right front headlight, and the other is located inside the RE-EGI box at the top of the intake plenum.

These sensors are used to tell the engine what temperature the incoming air charge is at, which determines how much fuel to mix with that incoming air. When cold out, the air density is greater, and more fuel is required to get good ignition and combustion.

One other sensor to check is the engine temperature sensor mounted on the back of the water pump, facing the engine. This is right near the thermostat, and it can also send a 'cold' condition to the ECU, which then tells the injectors they need to put out more fuel.

Either case will result in too much fuel.

If you check those for continuity using the FSM and don't fix the problem, you should also look at the Thermowax Pellet (search here). It's like an automatic choke. This is another coolant temperature probe which tells the engine how much air to mix - the Thermowax Pellet melts with warm engine coolant temp, and allows the secondary throttles (butterfly valves in the secondary intake path) to open fully, allowing full airflow.

When cold, the engine does better with a rich mixture (part 1 above on the temp sensors), and with reduced airflow (part 2, the thermoax pellet and secondary throttles).

If that doesn't fix it, I'd hook up a fuel pressure gauge (0-70psi for fuel injected engines) and see what it reads. Could be you're getting too much pressure which is overriding the Fuel Pressure Regulator on the front of the fuel rail.

Have a look and see what you find,

Welcome back LongDuck, long time, no posts. Your insight on SEs has been sorely missed.

thanks for the responses, I place a call to MAzdatrix order new plugs cables cap and rotor. hopefully this will help with beter spark.

I got a copy of the FSM and wiring schematics. not sure how to test this sensor to see if they are operating properly so any how to will be appreciated.

Long Duck hwere in the front is this other sensor?? I see the one in the intake and how do we check them?
after cleaning the cap and rotor plus the plugs, checked the power to the sensors and putting al together it flooded again.
it just wont start.

the coils are working the igniters too. plugs initial spark is good but it gets weak.

I plan to go through the complete wiring I also suspect of faulty ground boy what a nightmare.

As user 'Trochoid' pointed out, I've been out of the diagnostic game for quite awhile and have just been enjoying driving my car for the past year or so instead of posting here.

The FSM outlines how you can ground the connectors and test for idle changes, which is a positive indication that the sensor is working - I don't remember the specifics, and you'll have to check the FSM to get that detail.

The 2 air temp sensors are plugs that screw into the AFM at the front - may have to remove your airbox to see it, and also at the RE-EGI chamber - they look identical, and the computer uses both signals to determine fuel mixture. These are single-lead thermostats, so look for single lead connectors - I think they're both green, but FSM will tell you.

If you change cap/rotor/plugs, you might get better starting, but you're still not fixing the crux of the issue - fuel mixture. Keep that in mind.

Also, when was the last time you checked your fuel mileage? That can tell you a lot about your fuel mixture in all conditions short of installing a short- or wide-band O2 sensor lead and mix gauge. Your SE should be getting somewhere between about 18mpg and 20mpg for mixed city/highway driving. This would indicate a 'good' tune with quality plugs, fresh oil, and tires at proper temperature. Anything less than that (unless you have mods installed) and you may be running rich all the time and not know it.

LongDuck welcome back to the club.


To the OP.

Make sure you have ample cranking power. If the SE does not have adequate cranking power it may not develop proper cranking compression and will flood. This is more so if the engine has high mileage or the ignition components are worn.

I recommend that you get another jumper vehicle hooked up to your SE then disconnect the fuel system and crank the engine over with a piece of white paper in front of the spark plug holes until there is no more fuel residue coming out. Then squirt a little bit of oil in the holes.
Put the plugs back in and enable the fuel system. Then try to restart with the jumper vehicle hooked up.

Ok thanks for the great advice. I have not been here in a long time and initialy did not have my cobra here in korea. I thouht being close to Japan would help me mod and restore the car.

for the benefit of all your valuable, and appreciated advice.

My car is bone stock

85K on the Odometer right now.

I had a Rb header and took it off running stock exhaust now

it used to start like a charm but some idle problems.

did not use the car for a while, so the problem got worst.

I found the sensor on the EFI , will take apart the airbox again and look for the other one.

one more favor please , since I call MAZDATRIX and they dont ofer the sensors where can I get them from.

I read on MAZDA RX7 performance handbook published by Mike Ancas in 2000
I quote

" PG 62 And here is a final tip for GSL-SE owners: If you substitute 1986-1987 EGI Air flow meter for you current one you gain a few horsepower." end of quote

I really hate the stock box and was considering this I guess the 86-86 AFM will plug is the same plus want to go with a cone AF

I order a preassure regulatos from Black dragon LTD 99.95 too expensive in Mazdatrix just because the one there has been there for 23 years.

`pulsation damper is not leaking but the screw was off when I remove the cap so I put it back in

no vacum leaks will recheck again.

So I want to replace the sensor just to be on the safe side and will send the injectors to be tested and service.

As I stated on my post I want to keep it FI . so your help and experiences are greatly appreciated.

This is also stated in "How to Modify Your RX-7". I believe it is one of the few incorrect statements in both books. I do not know anyone who has swapped the AFMs successfully. The electronic signals are totally different. Here is the best info I know about.
http://www.jimrothe.com/mazda/afm_project/index.html

If you need used sensors or other intake parts that are unavailable new, I have most of them from engines I have disassembled.
https://www.rx7club.com/1st-generation-rx-7-1979-1985-parts-101/fs-84-gslse-part-out-more-826439/

I doubt that your Air intake sensors are an issue. In the over 20 years that I have had SE's not once have I had an issue with the Air intake sensors causing an issue.

The coolant temp sensor at the back of the water pump housing is the most critical one that can and will cause extreme issues with fuel and start up.

I would not just start throwing unneeded components at your issue unless you have a abundance of cash to get rid of.

Start with your basics as in the tune-up items that you stated and sending the injectors out to be cleaned and tested. That is all I recommend that you do at this moment.

74RX4 thanks for the info very interesting. RX-7 doctor thanks as well. I believe part of the problem besides the common plug wire etc. could be the coolant temp Sensor I will shop around for a new one, if any one has one send me PM with price or email to booricua@yahoo.com
Or let me know where I can order one from.

As of right now just waiting on parts to get her to Korea I love the Army postal service so fast:rolleyes:

Hi guys: I've been following this thread religiously since I'm having the same problem.

Could you please look at http://www.mazdatrix.com/79-85Electrical-Engine.htm

There is a part listed as 'no longer available' 74-85 Thermo switch in back of water pump housing

Or, is the sensor thats being referred to that affects the air/fuel mixture a connector with a GREEN end listed here: 84-92 13B Water Thermo Sender, Behind W/P

Thanks

That particular switch is for the carbureted vehicles and operation of the electromagnetic choke.

The coolant temp sensor is for the FI engines and is the number listed here-

18-8400-8574

It can also be ordered at any auto parts store.

Update
 

First off let me thank everyone who responded to this thread. Tody I finnaly recieved my parts all except the fuel preassure regulator. Threwin the plugs cable , cap and rotor and it started right up:icon_tup:

Still idle rough and smoked like hell :scratch:must be the extra oil idump in it LOL...

upon close look I noticed a fuel leak OH CRAPS , at least I drove it into the bay no more pushing LOL, upon closer inspection the o ring for the fuel injectors were worn, so put some new o rings problem solved.

Now IS the coolant line leaks WTF:icon_no2: no biggie tomorrow I wil replace all lines.

now I want to replace the fuse link for an FC fuse box so if anyone has one shoot me a PM. I will post on WTB

Thanks to all this is an invaluable forum for RX

work in progress:)

Yahooooooo
 

IT's ALIVE today I replace the stock coolant hoses for some heavy duty ones, new clamps too no more leaks, INDEED want to thanks everyone that helped me with this.

I drove the car for a good 30 minutes and shifted at 7,000 rpm no power shift but feel like the power is back.

I still have to work on some other issues. fine tune the Air fuel mixture, idle and flush the radiator will do that tomorrow. also change the oil and filter and new, plugs and check the timing.

One thing I noticed for a while is the oil PSI at idle is low at 3,000 rpm is like 59 PSI
so after tune want to check the where this can come from any ideas post up please.:)

also it seems extremly hot but gauges read normal.

Oil pressure gauge sounds normal. What makes you think its hot? That would not be a good thing. The stock gauges are not very accurate, but if temp gauge reads 1/2 way or below its probably OK.

Have you found this? I know it's long, but it's worth it.
http://mrmazda.no-ip.com/gslseidle.html