1990 FC Non-turbo Fuel/Fuel line problems

5

Asked by Eric Oct 27, 2009 at 07:00 PM about the 1990 Mazda RX-7

Question type: Maintenance & Repair

I am having trouble with my 1990 FC, Non turbo 13B, fuel doesnt seem to be getting to the engine, although the fuel pumps and injectors are working, the only problem i can see is clogged fuel filters, but that doesnt seem like it could be that bad, the whole car has been kept very well, although i am not too knowledgable on these cars yet... luckily i also dont have my license yet so i cant really harm it

30 Answers

635

Could be a ton of things. If you dont know how to troubleshoot it best to just get it checked out at a mechanic.

5

i meant to reply to your post but i accidentally reported it... i meant to say thanks for the insight but i reported it, sorry about that

55

I had a similar problem w/my 85 gsl-se and it turned out to be my engine computer

1 people found this helpful.
155

I would trace the problem starting with the cheapest fix and working from there. Check and replace your fuel filter and lines. Look at the pump anyway it might not be pumping just bad and whining. After that diagnosing the problem gets considerably more challenging. As far as the ECU being the cause; it is possible, but unlikely, the RX is notorious for having ECU and wiring problems. It seems to me that if the pump is working and so are the injectors and your not getting fuel, than the problem would be spark related if the filter and lines are ok. Take the fuel inlet line off of the fuel rail and turn the motor on (two person job), does fuel come out of the line? If so than its an issue with spark. All of the above is only accurate if you have fuel in the gas tank.

1 people found this helpful.
635

Dear god. What if you have flooded pistons.

1 people found this helpful.
155

Lol! Not sure if there is sarcasm in that post or not, considering the rotary motor doesn't have pistons.

1 people found this helpful.
5

thank you very much for this, i just remembered one more thing also, the mechanic that took a look at it, he said that i should look information on the fuse relay, i decided to flip through a haynes manual, but i found nothing, just an extra bit of info, he also checked the fuel pump and said it is working

25

my rotary motor has pistons! ithas 8 of them to be precise.

1 people found this helpful.
5

oh come on man! if your gonna put a piston engine in an FC go for a 2JZ from a supra, V8s are guzzlers

25

wow you really dont know. ls motors get way better gas mileage then a 2jz motor. my buddies heads cam ls1 does and average of about 26-28 mpg.i know for a fact that the supra motor doesnt do that cause ive owned them and im a member on the boards and hear all abou the shitty gas mileage.

25

its the v8 motor thats in the newer 98-2002 camaro/firebirds and in the corvettes

5

well i dont mean to sound like im arguing but i thought those have absolutely shit mileage

25

nope they actually get really good gas mileage. my buddies c5 z06 averages around 28mpg or so.

155

Im a big fan of the Ls swap to any RX7, I went for a ride in one with the six speed and ls3 from a vette. Stunning, amazing, awe inspiring. And to boot the guy got 35 mpg on the highway in 6th at legal speeds.

25

wouldnt really be a shit choice. it all depends on what you want to do.

25

i mostly did it cause its cheap to build a ls style motor. 2jz motors are exspensive especially if you wanna do turbo upgrades and stuff liek that. im maybe into my car about $4,000 right now and its pretty much complete. a 2jz would be a hell of alot more then that.

635

Well if it fits, why not? But I think that the 13B T is good enough of an engine.

55

Ignore the piston guys, You have the only car made with a rotary engine...yes a LS1 swap is cool but, it is not what the Rx7 was made for. 20b(3-rotor) would be the way to go if you want big rotary HP. Big $ though.... Back to your simple problem. If you have you pump and injectors working and you are getting spark(put a timing light on it to b sure), it may just be flooded. You can pull the egi fuse(kills fuel delivery) up by the front drivers shock tower and turn it over a few times to clear it out.....pulling lower(leading) plugs and putting in fresh ones also help a ton. Since you have a post 89 you can also hold the gas pedel to the floor and it will also cut fuel. These cars flood very easilly. Good luck.

1 people found this helpful.
155

Well if you've got nothing but money to import or fabricate a 20b go for it. I know of one 20b JDM for 4k not including ECU or Transmission. Also you would need to ship it from Japan. All said and done with the parts you will need to do that swap your going to be spending around 10K on the major stuff. As far as saying a LS swap as an option its not super cheap either you'll end up about 7-8k complete assuming you do all the work yourself. I would stick with the 13b you have and learn about it. It is an interesting motor, and with porting and some hefty boost it will be a quick ride. I honestly don't think that for cost to power you can make it as fast as an LS swap though. In the end though it is your car and you are going to do what you want with it, as you should. Do the research, decide if you want to stay semi stock or go to a full out swap.

155

As a quick follow up I did find a 2jz gte with harness, ecu, transmission and complete long block for $6500. Two minutes on ebay and I found an LS1 for $500. But I digress, we are getting off the topic of your fuel delivery problems. Any updates for us?

5

not yet, i still have to get around to getting my mechanic to look at it, luckily its as easy as getting my dad to call his friend, but the problem is theyre both always busy, so ill update when possible, thanks a lot for the help too

Hey guys I have a ? I have an 88 rx7 put new fuel pump new injector relay but my injectors are not getting any power thankful for any help please god bless

I had the same problem with my 83 RX7 non turbo 12a motor and it ended up being the sock in the gas tank was ripped and sucking rust through the fuel line and fuel pump clogging everything up

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