1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Starving above 4500 RPS's

Thread Tools
 
Search this Thread
 
Old 07-01-05, 01:19 PM
  #1  
"1ST GENS" THE REAL RX-7!

Thread Starter
 
jfachner72's Avatar
 
Join Date: Apr 2005
Location: long island
Posts: 861
Likes: 0
Received 0 Likes on 0 Posts
Starving above 4500 RPS's

Just something to throw out.

My 84 12a seems to be starving for fuel over 450000-5000 RPM's Its all bone stock with the nikki and full factory exaust including cats. The rats nest is still intact and i have no vac leaks.

It will run right up to the red-line in neutral but under load it wants to sputter a little and runs out of gas @ 4500-5000.

The car has 114k on it and not even a whisp of smoke some of the NY guys have seen her and can attest to how clean she is.

If anyone has an idea please let me know.


Thanks
Jay

1984 GSL Misty Blue Metallic bone stock
Old 07-01-05, 04:31 PM
  #2  
84SE-EGI helpy-helperton

 
LongDuck's Avatar
 
Join Date: Oct 2002
Location: Phoenix, AZ
Posts: 3,315
Received 360 Likes on 250 Posts
One shot fix: replace fuel filter.

The problem with the fuel filter on these cars is that once they get clogged, they prevent the carb bowls from getting adequate pressure to keep them full under WOT and high speed operation. As the fuel pump is running without load, the engine doesn't require that much fuel to get to redline. Under a load, the fuel demands are very high, and will require at least 4-6psi (carb) in order to supply enough fuel to keep accelerating.

The FF is located under the car on the left side, just in front of the rear axle. It usually hangs in a metal wire hanger and is held on the line with 2 hose clamps. Make sure that your replacement filter is flowing the right direction, and then get the hose clamps tight.

Reply back if that doesn't fix it - I think it will...
Old 07-01-05, 05:11 PM
  #3  
Lives on the Forum

iTrader: (5)
 
84stock's Avatar
 
Join Date: Apr 2003
Location: calgary
Posts: 5,537
Likes: 0
Received 9 Likes on 5 Posts
May be starving on "air". Mine would fall on it's nose at 5000 rpm until I went to the 14" air cleaner with a K&N filter.
Old 07-01-05, 08:39 PM
  #4  
Just soak it in 2-cycle

iTrader: (2)
 
RustyRotary's Avatar
 
Join Date: Mar 2005
Location: West Lafayette, IN
Posts: 576
Likes: 0
Received 0 Likes on 0 Posts
"Starving above 4500 RPS's"

270,000 RPMs? Wow, you're really going for a high-rev engine! I'm happy with the 8,000 mine can do












Sorry, couldn't help it
Old 07-02-05, 09:31 AM
  #5  
"1ST GENS" THE REAL RX-7!

Thread Starter
 
jfachner72's Avatar
 
Join Date: Apr 2005
Location: long island
Posts: 861
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by RustyRotary
"Starving above 4500 RPS's"

270,000 RPMs? Wow, you're really going for a high-rev engine! I'm happy with the 8,000 mine can do



I noticed that i typed that after the post. Just shows that some of you are on the ball.

It is a R26B 4 Rotor Turbine motor that WOT hits 300,000 RPM's

Thanks for the laugh, and the help with the filter prob.

jay








Sorry, couldn't help it
I noticed that i typed that after the post. Just shows that some of you are on the ball.

It is a R26B 4 Rotor Turbine motor that WOT hits 300,000 RPM's

Thanks for the laugh, and the help with the filter prob.

jay
Old 07-05-05, 08:09 AM
  #6  
"1ST GENS" THE REAL RX-7!

Thread Starter
 
jfachner72's Avatar
 
Join Date: Apr 2005
Location: long island
Posts: 861
Likes: 0
Received 0 Likes on 0 Posts
ok so i replaced the fuel filter ($4.07) i love cheap parts.

and alas no better....

I was wondering if my cats may be clogged and how i go about checking them?

Tomorrow i am going to do the dizzy,plugs,wires etc.etc.

does anyone else have any ideas????

jay
Old 07-05-05, 08:16 AM
  #7  
Lives on the Forum

 
Kentetsu's Avatar
 
Join Date: Jun 2004
Location: Grand Rapids Michigan
Posts: 11,359
Received 14 Likes on 11 Posts
Main jets may be clogged.....

These are the symptoms that I had when this happened to me...

1. Car runs fine until you pass about 80% on the throttle. Then it looses power.
2. Going at highway speeds, you can let off the gas for a few seconds and then floor it with no difference (still lags). This test shows that you are not just outrunning your fuel pump because it gives the carb a chance to "catch up" (refill the float bowls with fuel) while you are off the throttle.

If your symptoms closely match those, then it is probably time for a carb rebuild. The main jets can get some buildup on them, which restricts the flow at higher demand levels. You can get enough fuel through for easy driving, but not enough for full throttle.

Hope this helps....
Old 07-05-05, 09:11 AM
  #8  
RX for fun

iTrader: (13)
 
Siraniko's Avatar
 
Join Date: Aug 2001
Location: Socal
Posts: 15,926
Likes: 0
Received 22 Likes on 19 Posts
If I were you, I will start with the filter in the carb itself as in JUNK IT; not the external filter. then do the above posts.
Old 07-07-05, 08:20 AM
  #9  
"1ST GENS" THE REAL RX-7!

Thread Starter
 
jfachner72's Avatar
 
Join Date: Apr 2005
Location: long island
Posts: 861
Likes: 0
Received 0 Likes on 0 Posts
i didnt know there was a filter in the carb???

where is it???

jay
Old 07-07-05, 08:25 AM
  #10  
Ricer

iTrader: (4)
 
IanS's Avatar
 
Join Date: Jun 2004
Location: Washington, Iowa
Posts: 4,424
Likes: 0
Received 1 Like on 1 Post
Where the fuel lines connect to the carb, there are 2 bolts on top of this "Y" or "U" shaped piece. Take off those bolts and attached to the bolts are small screens that are there as a last chance filter just in case something is missed by the main fuel filter.
Old 07-07-05, 08:36 AM
  #11  
Junior Member

 
rotorbloop82's Avatar
 
Join Date: Jun 2005
Location: australia
Posts: 27
Likes: 0
Received 0 Likes on 0 Posts
tighten the screws at the top of the carb as they tend to loosen up with age'VIBRATIONS', HAD THE SAME PROBLEM AS YOU, I tightened the top plate of the carb and no more problems. That might be your problem! Jay
Old 07-09-05, 08:40 AM
  #12  
"1ST GENS" THE REAL RX-7!

Thread Starter
 
jfachner72's Avatar
 
Join Date: Apr 2005
Location: long island
Posts: 861
Likes: 0
Received 0 Likes on 0 Posts
help.............

i still have a starving problem over 4000 rpm's i did the fuel filter and checked every vac hose by hand.

the only thing i notice is that my exhaust smells very strong, not like gas but it has a strong smell ....

any ideas??????

jay
Old 07-09-05, 01:53 PM
  #13  
Rotary Freak

 
hanman's Avatar
 
Join Date: May 2001
Location: Peoria, IL
Posts: 1,779
Likes: 0
Received 0 Likes on 0 Posts
fuel pump or plugged cats.
best guess.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Rotospectre
New Member RX-7 Technical
3
03-28-18 03:33 PM
matty
3rd Generation Specific (1993-2002)
40
10-06-15 09:13 PM
Jmolina0163
1st Generation Specific (1979-1985)
19
09-25-15 06:06 PM
localized
New Member RX-7 Technical
3
09-16-15 12:18 AM
zxrazorxz
3rd Generation Specific (1993-2002)
2
09-14-15 07:21 PM



Quick Reply: Starving above 4500 RPS's



All times are GMT -5. The time now is 12:39 AM.