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

Rx7 runs but won't accelerate

Thread Tools
 
Search this Thread
 
Old Dec 22, 2015 | 05:01 PM
  #1  
Roddy Marie's Avatar
Thread Starter
Junior Member
 
Joined: Dec 2015
Posts: 15
Likes: 0
From: Marrero,La
Rx7 runs but won't accelerate

Hi guys I just bought a 1986 rx7 it will start with a tow and run but will not accelerate.I was want to kno if it's a quick fix it's a 13b 5 speed 126000 miles on the engine.I want to just swap it with a 2jz my question is this,if I have a aftermarket ems for the 2jz do I still need a custom harness made for the car and engine to work.
Reply
Old Dec 22, 2015 | 05:58 PM
  #2  
Roddy Marie's Avatar
Thread Starter
Junior Member
 
Joined: Dec 2015
Posts: 15
Likes: 0
From: Marrero,La
So can anyone give me any help please
Reply
Old Dec 23, 2015 | 10:52 AM
  #3  
KansasCityREPU's Avatar
Out In the Barn
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (9)
 
Joined: Mar 2005
Posts: 6,704
Likes: 1,250
From: KC
Bad clutch disc or glazed flywheel. I purchased a 1986 in this shape. Engine ran fine, revved good, idled great, but would not move under it's own power. Cost me $200 for a new clutch disc, plate, to bearing, and used flywheel.
Reply
Old Dec 23, 2015 | 12:16 PM
  #4  
Roddy Marie's Avatar
Thread Starter
Junior Member
 
Joined: Dec 2015
Posts: 15
Likes: 0
From: Marrero,La
And it only starts with a tow
Reply
Old Dec 23, 2015 | 12:26 PM
  #5  
heynoman's Avatar
heynoman
Tenured Member 15 Years
iTrader: (5)
 
Joined: Jul 2009
Posts: 469
Likes: 1
From: Illinois
Your going to have to be more specific. Only starts with a tow could mean several thing: starter doesn't work or faulty ignition switch broken flywheel ring, or you might mean that the engine turns but never starts....... If it starts with a tow your clutch might be engaging and not slipping and you may just have a bad engine. Or maybe a broken throttle cable. It could be anything. Starts with a tow and doesn't accelerate is a bad description of your problem. Help us help you.
Reply
Old Dec 23, 2015 | 06:53 PM
  #6  
KansasCityREPU's Avatar
Out In the Barn
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (9)
 
Joined: Mar 2005
Posts: 6,704
Likes: 1,250
From: KC
Generally, it the car requires a twoor push down a big hill to get started, then we know it's getting spark and fuel. Three things come to mind next: Bad starter, bad battery, or low compression.

1. Swap the battery with one that has lots of juice.
2. The next thing is to have the starter tested.
3. The next would be to do a compression test.
Reply
Old Dec 23, 2015 | 11:10 PM
  #7  
Roddy Marie's Avatar
Thread Starter
Junior Member
 
Joined: Dec 2015
Posts: 15
Likes: 0
From: Marrero,La
Ok I'm going to find out exactly how to describe it
Reply
Old Dec 24, 2015 | 12:20 AM
  #8  
misterstyx69's Avatar
Retired Moderator, RIP
Tenured Member: 20 Years
iTrader: (142)
 
Joined: Sep 2005
Posts: 25,581
Likes: 136
From: Smiths Falls.(near Ottawa!.Mapquest IT!)
Quite frankly,It sounds like your engine is toast.
But you will not know that until you perform a Compression test(look that up via the handy search function).This test will tell you right off the bat if you are fighting a losuing battle.
If the compression is good then you can proceed knowing that your engine is not your problem and that it may lie in fuel delivery.

If you want to do a swap then there are other sections that have info on that(Other engine conversion section).There are many alternatives for that depending on how handy you are and how much you want to go in the hole..I mean spend..lol!
Reply
Old Dec 25, 2015 | 07:33 PM
  #9  
Radar84SE's Avatar
Junior Member
 
Joined: Dec 2015
Posts: 24
Likes: 0
From: Alabama
I found several vacuum leaks(not on a rotary), faulty fuel pump, and bad injectors. I haven't performed the injectors yet. How do I know they're bad? The fuel pump never primes up and stops just keeps running due to stuck open injector. And then we flood out. If I didn't love the sound and performance of these cars I'd get rid off them. Best of luck!
Reply
Old Dec 26, 2015 | 02:54 PM
  #10  
KansasCityREPU's Avatar
Out In the Barn
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (9)
 
Joined: Mar 2005
Posts: 6,704
Likes: 1,250
From: KC
Originally Posted by Radar84SE
I found several vacuum leaks(not on a rotary), faulty fuel pump, and bad injectors. I haven't performed the injectors yet. How do I know they're bad? The fuel pump never primes up and stops just keeps running due to stuck open injector. And then we flood out. If I didn't love the sound and performance of these cars I'd get rid off them. Best of luck!
You might want to start your own thread instead of posting in someone else's with your issues.
Reply
Old Dec 26, 2015 | 07:54 PM
  #11  
Radar84SE's Avatar
Junior Member
 
Joined: Dec 2015
Posts: 24
Likes: 0
From: Alabama
Why?

Originally Posted by KansasCityREPU
You might want to start your own thread instead of posting in someone else's with your issues.
I was simply stating the issues I had found to try and help. J/A
Reply
Old Dec 31, 2015 | 09:28 PM
  #12  
Radar84SE's Avatar
Junior Member
 
Joined: Dec 2015
Posts: 24
Likes: 0
From: Alabama
Have you had a chance to figure out what the issues are?
Reply
Old Jan 1, 2016 | 10:21 AM
  #13  
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
Car been sitting? Could be as simple as a bad injector, which is VERY common.

But more details are necessary.

Perform a compression test.
Reply
Old Jan 1, 2016 | 06:38 PM
  #14  
Radar84SE's Avatar
Junior Member
 
Joined: Dec 2015
Posts: 24
Likes: 0
From: Alabama
fingers crossed

That's always the nerve racking part. Fingers crossed. So just to clarify...battery is good? Starter good? Fuel? ignition? Are the vacuum lines good? if hard and brittle replace. Most guys will tell you to put it back to stock if already stock, get it running right THEN delete the emissions.
Reply
Old May 1, 2016 | 04:09 PM
  #15  
Roddy Marie's Avatar
Thread Starter
Junior Member
 
Joined: Dec 2015
Posts: 15
Likes: 0
From: Marrero,La
Originally Posted by Radar84SE
That's always the nerve racking part. Fingers crossed. So just to clarify...battery is good? Starter good? Fuel? ignition? Are the vacuum lines good? if hard and brittle replace. Most guys will tell you to put it back to stock if already stock, get it running right THEN delete the emissions.
Ok i got more info car starts without a tow but if i give it gas slowly car dies if i mass it and hold it revs and its good if i let off it kills
Reply
Old May 1, 2016 | 04:16 PM
  #16  
satch's Avatar
Moderator
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Jun 2005
Posts: 11,738
Likes: 16
From: tulsa,ok.
Could be a vacuum leak or primary injectors are clogged.
Reply
Old May 1, 2016 | 04:30 PM
  #17  
Roddy Marie's Avatar
Thread Starter
Junior Member
 
Joined: Dec 2015
Posts: 15
Likes: 0
From: Marrero,La
Originally Posted by satch
Could be a vacuum leak or primary injectors are clogged.
Which ones are primary injectors and where the vacum lines located
Reply
Old May 1, 2016 | 04:40 PM
  #18  
satch's Avatar
Moderator
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Jun 2005
Posts: 11,738
Likes: 16
From: tulsa,ok.
Secondary injectors are the visible ones thus the primaries are the harder ones to access. Vacuum lines are located in different places. Spray carb cleaner while the engine is idling and if there is a vacuum leak then the engine will change in sound. A vacuum leak could come from other things than hoses such as gaskets or the injector grommets.
Reply
Old May 1, 2016 | 04:42 PM
  #19  
Roddy Marie's Avatar
Thread Starter
Junior Member
 
Joined: Dec 2015
Posts: 15
Likes: 0
From: Marrero,La
Originally Posted by satch
Secondary injectors are the visible ones thus the primaries are the harder ones to access. Vacuum lines are located in different places. Spray carb cleaner while the engine is idling and if there is a vacuum leak then the engine will change in sound. A vacuum leak could come from other things than hoses such as gaskets or the injector grommets.
I have a fuel injected 13b dont think i could use carb cleaner
Reply
Old May 1, 2016 | 04:50 PM
  #20  
satch's Avatar
Moderator
Tenured Member: 20 Years
iTrader: (1)
 
Joined: Jun 2005
Posts: 11,738
Likes: 16
From: tulsa,ok.
Originally Posted by Roddy Marie
I have a fuel injected 13b dont think i could use carb cleaner
you spray the cleaner to find a vacuum leak and nothing more!
Reply
Old May 1, 2016 | 05:30 PM
  #21  
Roddy Marie's Avatar
Thread Starter
Junior Member
 
Joined: Dec 2015
Posts: 15
Likes: 0
From: Marrero,La
Originally Posted by satch
you spray the cleaner to find a vacuum leak and nothing more!
Where do i spary it directly at
Reply
Old May 1, 2016 | 05:35 PM
  #22  
DC5Daniel's Avatar
Rotary Freak
Tenured Member 10 Years
iTrader: (10)
 
Joined: Jul 2012
Posts: 1,631
Likes: 89
From: Peachtree City, GA
Originally Posted by Roddy Marie
Where do i spary it directly at
Anywhere in the intake and vacuum path. Basically start at the air flow meter and work your way back. All vacuum lines, injector seals, emissions solenoids, everything is a suspect.

Just to be clear, are you familiar with why/what will happen if and when you identify a leak with this method? It doesn't sound like you are, which means you won't even know you've found the leak!

The cliffnotes are you're going to notice a surge in idle speed when the cleaner is ingested into the motor via a leak. Do a quick YouTube search and you'll have a better understanding of what's going on.
Reply
Old May 1, 2016 | 07:12 PM
  #23  
Roddy Marie's Avatar
Thread Starter
Junior Member
 
Joined: Dec 2015
Posts: 15
Likes: 0
From: Marrero,La
Originally Posted by DC5Daniel
Anywhere in the intake and vacuum path. Basically start at the air flow meter and work your way back. All vacuum lines, injector seals, emissions solenoids, everything is a suspect.

Just to be clear, are you familiar with why/what will happen if and when you identify a leak with this method? It doesn't sound like you are, which means you won't even know you've found the leak!

The cliffnotes are you're going to notice a surge in idle speed when the cleaner is ingested into the motor via a leak. Do a quick YouTube search and you'll have a better understanding of what's going on.
Ok and once i fix it if there is one i should be able to drive the car
Reply
Old May 1, 2016 | 07:19 PM
  #24  
DC5Daniel's Avatar
Rotary Freak
Tenured Member 10 Years
iTrader: (10)
 
Joined: Jul 2012
Posts: 1,631
Likes: 89
From: Peachtree City, GA
Originally Posted by Roddy Marie
Ok and once i fix it if there is one i should be able to drive the car
IF that was your only issue, sure.
Reply
Old May 1, 2016 | 07:37 PM
  #25  
Roddy Marie's Avatar
Thread Starter
Junior Member
 
Joined: Dec 2015
Posts: 15
Likes: 0
From: Marrero,La
Originally Posted by DC5Daniel
IF that was your only issue, sure.
Ok its raining bad so once it stops imma get out thete and try that
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
afpreppie04
Megasquirt Forum
1
Nov 15, 2015 10:44 AM
realryan
New Member RX-7 Technical
15
Nov 10, 2015 03:09 PM
rx7jocke
Single Turbo RX-7's
7
Nov 3, 2015 10:08 AM
lookingforRX7FD
General Rotary Tech Support
3
Nov 2, 2015 10:34 AM




All times are GMT -5. The time now is 10:28 AM.