injector flow rate on an 87 GXL?
 

Anyone know the injector flow rate of an '87 GXL? These are peak and hold, right?

for the stock 460cc injectors per the FSM

111-118cc/15-sec or 6.8-7.2cu in/15-sec

They are controller by voltage variations from the ECU, not on/off.

If the 460s were replaced with TII 550s would you need a new fuel pump? Thanks.

Chris

P.S.

Anyone that knows how to fix Rx7s please let me know, tryin to figure out wuts wrong with mine :(

No, but you would either need a S-AFC to down tune them or an aftermarket ECU. Otherwise, you will run extremely rich, and foul plugs at first idle.

What is wrong with you RX-7?

I've got a plain jane 87NA with 550's in the secondaries only and its running just fine. I understand if you put 550's in the primaries and the secondaries you will have problems. Its 550's in the secondaries with a Mazdatrix dual from head to toe, K and N (overpriced and little effect). I'd like to complement fc3s.org site as being one darn good place to look for information. Thank you Dave Gibson and the other people who keep that site going for this novice.

With them in the secondaries, they are only used when you go over 3800rpm or so. The primeries are used from idle all the way to redline. How much time do you spend over 3800rpm? It is really bad for the O2 sensor, plugs and gas mileage to use them without a controller. The ECU cannot make changes for flow rates of injectors. It can't make changes to impedence of the injectors either.

Thanks for the compliments. The others are Joe Romeo, who is my right hand man with the site, and the Project 86, and John Zanol, who's 89 GTUs makes you cover your ears at idle =) Neither of them are on this forum if I'm not mistaken. I'll pass on the kind words this weekend when I see them.

It is my understanding that the fuel amount injected is determined by time open,so in fact they are on/off.So if you use the big injectors you need to modify the on/off timeto get the correct fuel amount for your engine conditions.

Depends on how you look at it. The injector pulses are controlled by voltage regulated by the ECU. The pulses are infact on/off. I was referring to the system as in it does not just have on or off, but rather it is variable, and determined by the ECU.

I only wish I knew. I think you answered me in the ECU/Electronics forum...I have no idea now. ONly thing I can think of is the fuel punp is shorted or my ECU is. I dunno. Need help badly. Any ideas what it is? If you need any more info let me know, I believe you read my other posts. Thanks.

Chris

Hey, how do you like the exhaust from Mazdatrix? I was thinkin of gettin it, but heard some problems it might have with the 6 ports in my 88. What kind of performance gains did you get? Thanks.

Dave Gibson....I realize that the post I made above almost sounded contadictive of what you said and it was not meant in that vein. I got the idea of the 550's from Mazdatrix and they were saying that 680's from a 85GSL in the secondaries would be an upgrade and did not mention anything else being required. I just noted that the 550's which I realize are only open at 3800, were working for me. I plan to put the 680's in , in the near future. RYDE OR DYE......The dual Mazdatrix work just fine. Its dual from exaust to tail pipe. The RAcing Beat header that is a part of it, has a 3/16 pipe coming out of the front rotor exaust port that gives you the pressure for the aux actuators. It works. There are several other cheap ways to get around the lack of a cat. By it. Make sure its the dual one. Head to tail. Bunch more power. I can pull 7500 in forth going UP hill and still climbing. I know its not the proper thing to do. Revs faster also.