2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

my fc is skipping

Thread Tools
 
Search this Thread
 
Old Sep 1, 2021 | 10:58 PM
  #1  
David Percario's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2020
Posts: 12
Likes: 0
From: chatham virginia
my fc is skipping

so for about a month now my fc while im driving has been well... skipping. idk how else to explain it than it feels like its skipping a heartbeat while im driving and sometimes it doesnt want to idle as in it'll shut off while im at a light and it'll start back up no problem. im suspecting a fuel pump i already changed spark plugs, plug wires, and fuel filter and ive heard fuel pump from someone but im open to any other ideas
Reply
Old Sep 2, 2021 | 01:24 PM
  #2  
Cardinell's Avatar
Rotatin'
 
Joined: Mar 2021
Posts: 383
Likes: 35
From: Virginia
Originally Posted by David Percario
so for about a month now my fc while im driving has been well... skipping. idk how else to explain it than it feels like its skipping a heartbeat while im driving and sometimes it doesnt want to idle as in it'll shut off while im at a light and it'll start back up no problem. im suspecting a fuel pump i already changed spark plugs, plug wires, and fuel filter and ive heard fuel pump from someone but im open to any other ideas
By "skipping" do you mean misfiring? If so, have you checked for vacuum leaks? Or have you checked your timing?
Reply
Old Sep 2, 2021 | 01:47 PM
  #3  
David Percario's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2020
Posts: 12
Likes: 0
From: chatham virginia
i havent checked any of that but i will now and also when this happens the needle on the tac bounces like itll go up and down really quick like its catching itself
Reply
Old Sep 2, 2021 | 03:19 PM
  #4  
Gregory Casimir's Avatar
Rotary Enthusiast
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (8)
 
Joined: Jun 2004
Posts: 1,416
Likes: 11
From: Miami , Florida
Check your plug connection/ condition on the CAS. If you have some loose pins in that harness, it will cause the motor to do that or completely shut the engine off.
Reply
Old Sep 5, 2021 | 02:19 PM
  #5  
Cardinell's Avatar
Rotatin'
 
Joined: Mar 2021
Posts: 383
Likes: 35
From: Virginia
Originally Posted by David Percario
i havent checked any of that but i will now and also when this happens the needle on the tac bounces like itll go up and down really quick like its catching itself
I would check the TPS while you're at it. Can't hurt to make sure it's calibrated properly.
Make sure the car is warm. Shut it off. Test resistance from the back of the TPS connector with it unplugged from the actual sensor. Should be ~1v at closed throttle and ~5v at WOT.

But, like Gregory Casimir said, check the pins on the harness that goes to the CAS. That could be another cause.
Reply
Old Sep 7, 2021 | 04:20 AM
  #6  
David Percario's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2020
Posts: 12
Likes: 0
From: chatham virginia
so ive checked the wires and they all seem to be good and fine i havent tested anything yet and probably wont be able to for a bit but ive noticed another way to describe the skipping as its like if your driving and you were to let off the pedal for a split second and go back on over and over while driving
Reply
Old Sep 7, 2021 | 05:43 PM
  #7  
Cardinell's Avatar
Rotatin'
 
Joined: Mar 2021
Posts: 383
Likes: 35
From: Virginia
Originally Posted by David Percario
so ive checked the wires and they all seem to be good and fine i havent tested anything yet and probably wont be able to for a bit but ive noticed another way to describe the skipping as its like if your driving and you were to let off the pedal for a split second and go back on over and over while driving
It does that at idle? Do you have a video?
Reply
Old Sep 7, 2021 | 05:52 PM
  #8  
David Percario's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2020
Posts: 12
Likes: 0
From: chatham virginia
no it only happens while driving and the only idle issue at a light the revs would go down then the car would shut off but thats only happened twice
Reply
Old Sep 8, 2021 | 08:00 AM
  #9  
Cardinell's Avatar
Rotatin'
 
Joined: Mar 2021
Posts: 383
Likes: 35
From: Virginia
Originally Posted by David Percario
no it only happens while driving and the only idle issue at a light the revs would go down then the car would shut off but thats only happened twice
So it briefly loses power while accelerating? Does it happen around 3800 rpm?
Reply
Old Sep 8, 2021 | 11:45 AM
  #10  
David Percario's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2020
Posts: 12
Likes: 0
From: chatham virginia
yeah pretty much for like half a second and it can happen anywhere in the rev range but ive noticed it happen more arounf 6k in 3rd gear and around 4k in 4th gear
Reply
Old Sep 9, 2021 | 02:08 PM
  #11  
Cardinell's Avatar
Rotatin'
 
Joined: Mar 2021
Posts: 383
Likes: 35
From: Virginia
Originally Posted by David Percario
yeah pretty much for like half a second and it can happen anywhere in the rev range but ive noticed it happen more arounf 6k in 3rd gear and around 4k in 4th gear
I'd say you're probably looking for a vacuum leak.
But, just to narrow it down, make sure the TPS is set properly and that your timing is correct.
Also, if you're able, try cleaning your ECU ground.
Reply
Old Oct 20, 2021 | 10:29 PM
  #12  
David Percario's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2020
Posts: 12
Likes: 0
From: chatham virginia
sorry for the long delay on this better response my transmission has been dying and that has become my main concern and ive been working and doing school but yes i do have videos of it stuttering which is the word i probably should have used to begin with and for more details and refreshing it stutters mainly in 3rd gear and up and it'll do it throughout the rev range but mainly from 3k rpm - 6k rpm and often when it gets to 6k it doesn't want to go any higher like the stuttering is preventing it along with that idk if this might be related but on cold starts the throttle needs to be help very slightly for a little bit but from then on it'll start no problem im hoping for more answers or ideas from everyone and thank you to everyone who've already given some help
Reply
Old Oct 21, 2021 | 12:04 PM
  #13  
Cardinell's Avatar
Rotatin'
 
Joined: Mar 2021
Posts: 383
Likes: 35
From: Virginia
Originally Posted by David Percario
sorry for the long delay on this better response my transmission has been dying and that has become my main concern and ive been working and doing school but yes i do have videos of it stuttering which is the word i probably should have used to begin with and for more details and refreshing it stutters mainly in 3rd gear and up and it'll do it throughout the rev range but mainly from 3k rpm - 6k rpm and often when it gets to 6k it doesn't want to go any higher like the stuttering is preventing it along with that idk if this might be related but on cold starts the throttle needs to be help very slightly for a little bit but from then on it'll start no problem im hoping for more answers or ideas from everyone and thank you to everyone who've already given some help
If you're losing power past 3k rpm and it won't rev higher than 6k, you may have a different issue entirely. Id say smoke test the engine to see if you have a vaccum leak. If you don't find one, I would check the pressure sensor near the passenger side strut tower. The FSM should have a procedure to check to see if the sensor is good or not.
Make sure your 6 port actuators are working. Push down on the rods on top of them to see if the fully open and close. They're driven by back pressure from the exhaust, so make sure you don't have a major exhaust leak either.

Depending on how much work you're trying to do, cleaning the ECU ground wouldn't be a bad idea either. It sits on top of the block, right underneath the dynamic chamber. If this ground is corroded or isn't clean, it can cause all sorts of weird issues.

Is your FPR good? Your fuel pump?

​​​​
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
chucktownrx7
New Member RX-7 Technical
32
Jul 14, 2012 04:34 AM
jesse_fc3
2nd Generation Specific (1986-1992)
1
Apr 25, 2008 03:28 AM
ThoRx7
2nd Generation Specific (1986-1992)
6
May 16, 2007 02:52 AM
Nesgroeg
2nd Generation Specific (1986-1992)
1
Apr 9, 2007 07:16 AM
dibustibun5
2nd Generation Specific (1986-1992)
16
Jun 21, 2003 07:33 PM




All times are GMT -5. The time now is 06:03 PM.