New Member RX-7 Technical Post your first technical questions here, in an easy flame free environment, before jumping into the main technical sections.

HELP fast please!!

Thread Tools
 
Search this Thread
 
Old Oct 19, 2009 | 07:01 PM
  #1  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
AZ HELP fast please!!

hey i have an '86 rx-7 n/a.

i just finished troubleshooting and i've narrowed it down to the injectors/circuitry.

the fuel pump is new and when i open the air meter is sprays from the main fuel line.

but the injectors don't pulse???

what would cause this? and what should i check.

ALL the fuses are fine

thanks, Sean
Reply
Old Oct 20, 2009 | 09:18 AM
  #2  
Aaron Cake's Avatar
Engine, Not Motor
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Check the crank angle sensor.
Reply
Old Oct 21, 2009 | 03:41 AM
  #3  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
i checked it and the resistance was .161 on both sides of the clip.

how can i test the actual injector?
i have the primarys out right now.

the clip voltage for them changed when i tapped the ground against the bell housing.
Reply
Old Oct 21, 2009 | 03:42 AM
  #4  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
also tested the resistor box and it's good.

does the crank sensor have to spin to get injector pulse?

Last edited by fc3si; Oct 21, 2009 at 03:48 AM.
Reply
Old Oct 21, 2009 | 03:12 PM
  #5  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
it's a mystery.
Reply
Old Oct 21, 2009 | 03:19 PM
  #6  
Digi7ech's Avatar
I break Diff mounts
Tenured Member 20 Years
iTrader: (1)
 
Joined: Jun 2002
Posts: 4,403
Likes: 4
From: Avondale, Arizona
^yes, you need to spin the cas to make the injectors fire.

Check the CAS plug. Mine got loose one time and wouldn't fire.
Reply
Old Oct 21, 2009 | 03:25 PM
  #7  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
Originally Posted by Digi7ech
^yes, you need to spin the cas to make the injectors fire.

Check the CAS plug. Mine got loose one time and wouldn't fire.
so if i spin the CAS with the key set to "ON" i should get a pulse from the injector clip?

i'm pretty sure my CAS is good, i tested the resistance as per the service manual and it's within spec.
Reply
Old Oct 21, 2009 | 07:03 PM
  #8  
Digi7ech's Avatar
I break Diff mounts
Tenured Member 20 Years
iTrader: (1)
 
Joined: Jun 2002
Posts: 4,403
Likes: 4
From: Avondale, Arizona
I've done it before.

I pulled the CAS out(only do if you know how to put back in correctly) Then left it plugged in and key on. I spun it and heard all the injectors going off.

You can check the injectors going off by sticking a multimeter in to the backside of the ECU plug.
You'd have to check the Service manual to determine which pins are the injectors. You also shoudl only test the primaries. The secondaries won't come on unless you're over 3800 rpm.
Reply
Old Oct 21, 2009 | 07:55 PM
  #9  
Senior Member
Tenured Member 15 Years
iTrader: (2)
 
Joined: Feb 2003
Posts: 719
Likes: 0
From: Kingston Ontario
Also make sure that you are checking the right injectors. The Primary injectors are very difficult to get at. The secondary injectors are quite visibile and like Digi7ech said will not fire untill over 3800rpm.
Reply
Old Oct 21, 2009 | 08:05 PM
  #10  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
Originally Posted by Marek
Also make sure that you are checking the right injectors. The Primary injectors are very difficult to get at. The secondary injectors are quite visibile and like Digi7ech said will not fire untill over 3800rpm.
i know, i have the upper intake manifold off.
Reply
Old Oct 21, 2009 | 08:16 PM
  #11  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
i'm going to get a new battery 'cause mine exploded last night sending me to the E.R lol

after i get the new batt i'll check the voltage at the clips and check if the injectors click etc

thanks for the help people
Reply
Old Oct 22, 2009 | 01:37 AM
  #12  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
picked up some free 450cc DSM injectors, gonna try those out.


what's the flow rate on the stock primarys? 460cc right?
Reply
Old Oct 22, 2009 | 05:10 AM
  #13  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
okay, update...

installed DSM injectors and finally got pulse!!!

the car almost started then just bogged out.

and there's a major fuel leak.

i'm gonna do some investigating and repairs.

updates coming eventually.

thanks for the support..
Reply
Old Oct 22, 2009 | 01:57 PM
  #14  
irishpilot's Avatar
Senior Member
Tenured Member 05 Years
iTrader: (4)
 
Joined: Mar 2003
Posts: 273
Likes: 0
From: Bay Area, Ca
*** man, good luck...

SO youre injectors were bad? Or was it wiring?

--im having similar issue after my 13b swap....
Reply
Old Oct 22, 2009 | 03:10 PM
  #15  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
Yes, it was the injectors.

still won't start but that 'cause i have a bad fuel leak
Reply
Old Oct 22, 2009 | 03:44 PM
  #16  
irishpilot's Avatar
Senior Member
Tenured Member 05 Years
iTrader: (4)
 
Joined: Mar 2003
Posts: 273
Likes: 0
From: Bay Area, Ca
do you know if the 88' has a resistor box for the injectors?? I dont believe I have one for my swap....
Reply
Old Oct 23, 2009 | 04:09 AM
  #17  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
fixed everything. car still won't start. i have a feeling it's a timing issue.

i have everything set PERFECTLY and it still won't start?!

any pointers?
Reply
Old Oct 23, 2009 | 05:33 AM
  #18  
fc3si's Avatar
Thread Starter
Full Member
 
Joined: Oct 2009
Posts: 67
Likes: 0
From: Sedona, AZ
Get fuel, and when i pull the plugs they are wet.

gets spark, shocked myself a few times lol.

but it won't start!?

wtf?
Reply
Old Oct 24, 2009 | 10:20 AM
  #19  
Aaron Cake's Avatar
Engine, Not Motor
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
Likely flooded. You can put a little oil into each chamber to build up compression. Or, you can cut through the BS and just push start it with another vehicle. That always works.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Jeff20B
1st Generation Specific (1979-1985)
73
Sep 16, 2018 07:16 PM
Aramir
New Member RX-7 Technical
24
Oct 18, 2015 02:39 AM
Devon Murray
New Member RX-7 Technical
1
Sep 26, 2015 08:15 AM




All times are GMT -5. The time now is 06:31 PM.