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

fuel economy sucks and lack of power

Thread Tools
 
Search this Thread
 
Old 11-21-05, 03:06 PM
  #1  
Junior Member

Thread Starter
 
sunflower4140's Avatar
 
Join Date: Oct 2005
Location: sc
Posts: 37
Likes: 0
Received 0 Likes on 0 Posts
Unhappy fuel economy sucks and lack of power

OK i got a 1988 rx-7 na. when i first got the car it wouldnt crank so we push started it and we finally got to crank. It poured out white smoke because we put fuel injector cleaner in there because we thought that that was the problem and when we got it to crank i drove it for a little bit and it didnt have all the power that it was suppose to. So we pulled over at the gas station and got out and heard a gurgiling noise and u could just hear the coolant just bubbling. So we had it towed to the place we bought it from and had new plugs and wires put in and it would fire right up. Then it would floud time to time so somebody said to put a toggle switch on the fuel pump relay switch so we did. Then after a while of driving it, it started to completely lose almost all power. So back to the mechanic. He did a fuel pressure test on the whole system and said everything was good up until the fuel pressure regulator. So i ordered one. Got it put it on and it didnt help a damn thing. It still burns gas like hell, has no power, and smokes when u first crank it up after sitting over night, u have to keep ur foot on the gas to keep it running or it will cut off. Someone please tell me were to start cuz im new to the rx-7's and tired of the whole problem and nobody where im from knows how to work on the thing and i wanna learn them. So please help
Old 11-21-05, 03:13 PM
  #2  
Full Member

 
rx302's Avatar
 
Join Date: Oct 2003
Location: Clemson SC
Posts: 58
Likes: 0
Received 0 Likes on 0 Posts
where are you at in SC?
Old 11-21-05, 03:31 PM
  #3  
knowledge junkie

 
vaughnc's Avatar
 
Join Date: Mar 2001
Location: Atlanta, GA
Posts: 5,595
Likes: 0
Received 6 Likes on 4 Posts
could be a simple vacuum leak or electronic sensor not plugged in. Download the Service manual and read throught the troubleshooting sections:

http://www.teamfc3s.org/main/factory_service_manual/

Since you can get it to warmup & run, you should have a HOT compression test done on the engine with a ROTARY ENGINE SPECIFIC compression tester. That tester give you 6 compression numbers, 3 per rotor chamber.

Last edited by vaughnc; 11-21-05 at 03:36 PM.
Old 11-21-05, 03:34 PM
  #4  
Junior Member

Thread Starter
 
sunflower4140's Avatar
 
Join Date: Oct 2005
Location: sc
Posts: 37
Likes: 0
Received 0 Likes on 0 Posts
yea, i live in greenwood, south carolina
Old 11-21-05, 03:37 PM
  #5  
Junior Member

Thread Starter
 
sunflower4140's Avatar
 
Join Date: Oct 2005
Location: sc
Posts: 37
Likes: 0
Received 0 Likes on 0 Posts
could a vacum leak be causing bad gas mileage?
Old 11-21-05, 03:50 PM
  #6  
holley guy

 
mwatson184's Avatar
 
Join Date: Feb 2003
Location: K.C. MO
Posts: 898
Likes: 0
Received 0 Likes on 0 Posts
I doubt it is a vac leak. Sounds more like a blown seal to me. Do a compression test to find out for sure. Sounds like your motor has a blown coolant seal for sure though. What are the coolant temps while running?

-Marques
Old 11-21-05, 03:53 PM
  #7  
Junior Member

Thread Starter
 
sunflower4140's Avatar
 
Join Date: Oct 2005
Location: sc
Posts: 37
Likes: 0
Received 0 Likes on 0 Posts
ok pulled plugs out and the two on the left side have like a tanish brown tint to them like threre suppose to be and the right side smell like oil and are black so i know if that occurs in regular motors u may need to replace seals and rings so what needs to be done or what is causing this
Old 11-21-05, 03:56 PM
  #8  
Junior Member

Thread Starter
 
sunflower4140's Avatar
 
Join Date: Oct 2005
Location: sc
Posts: 37
Likes: 0
Received 0 Likes on 0 Posts
the temp gauge reads normal so what do u think needs to be done
Old 11-21-05, 04:01 PM
  #9  
Locust of the apocalypse

 
YearsOfDecay's Avatar
 
Join Date: Apr 2003
Location: Directly above the center of the earth (York, PA)
Posts: 2,553
Likes: 0
Received 1 Like on 1 Post
Somewhere, off in the distance, I can hear "taps" being played, gently, over a flowing field of wheat..... for your motor.

Sorry dude... Its shot....

Vac leaks don't cause that drastic a loss in power....

The Gurgling in the coolan system tells me that the motor has suffered a coolant seal destruction in the lower part of the iron, this also equated the the hard to start and the new plugs fixing the problem..

When you get a coolant seal leak in the compression/expansion side of the iron, it doesn't burn white smoke because the pressure keeps the coolant out while the car is running... When you shut the car off, the coolant will seep into the housing and foul the plug when you try to start the car.... You may never see a huge cloud of smoke, or it could on day turn into a crop duster... depends on the location and severity.

As for the loss of power.. could be the plugs fouling, could also be that the water has eaten the nitride coating off the side of the rotor housing on one of the rotors (especially if you've suffere the dreaded "Break" in the coolant o ring wall on the lower part of the front Iron) and the apex seals have thrasehed themselves... Sounds like its also suckin oil from the description of the plugs

Sorry man, know it sounds like doom and gloom, but, i've seen it hundreds of times.. somebody buys an RX for dirt cheap cause it won't run, and the old owner knows nothing (or claims to know nothing ) and just wants rid of it, and now you got a bomb on your hands..

pull the EGI fuse, Take the top plug out on the front, turn the car over, from the plugs description you should hear "pweee p[weee pweeee. Replace and do the same in the back... Bet it don't sound the same

Last edited by YearsOfDecay; 11-21-05 at 04:05 PM.
Old 11-21-05, 04:04 PM
  #10  
Junior Member

Thread Starter
 
sunflower4140's Avatar
 
Join Date: Oct 2005
Location: sc
Posts: 37
Likes: 0
Received 0 Likes on 0 Posts
u said it could be the coolant seals but i found a test for that on here somewhere. It said to take the radiator cap off and take the fuel injector fuse out and the engine computer fuse out or it might have said just take one of those out, i cant remember, but it said to try to turn the motor over and if any coolant comes out then the seals are bad but nothing came out. Does that ensure that the seals are defiently good or what.
Old 11-21-05, 04:07 PM
  #11  
Locust of the apocalypse

 
YearsOfDecay's Avatar
 
Join Date: Apr 2003
Location: Directly above the center of the earth (York, PA)
Posts: 2,553
Likes: 0
Received 1 Like on 1 Post
Originally Posted by sunflower4140
u said it could be the coolant seals but i found a test for that on here somewhere. It said to take the radiator cap off and take the fuel injector fuse out and the engine computer fuse out or it might have said just take one of those out, i cant remember, but it said to try to turn the motor over and if any coolant comes out then the seals are bad but nothing came out. Does that ensure that the seals are defiently good or what.
My TII suffered the "break" in the front Iron... where a piece of the coolant passage actually breaks off and dissappears into the coolant system.. I didn't have ANY sysmptoms other than it was hard to start if it sat for a while and gurgling from the front of the motor....

Didn't say it was definately the coolant seals... it COULD be something else.. but, its NOT a vaccume leak... You need to check the compression and you need to do that before you do anything else.
Old 11-21-05, 04:08 PM
  #12  
Junior Member

Thread Starter
 
sunflower4140's Avatar
 
Join Date: Oct 2005
Location: sc
Posts: 37
Likes: 0
Received 0 Likes on 0 Posts
So the best thing would be to have the motor sent off and have it rebuilt from ground up
Old 11-21-05, 04:11 PM
  #13  
RIP Icemark

iTrader: (4)
 
Tournapart's Avatar
 
Join Date: May 2005
Location: Mesa, AZ
Posts: 1,019
Likes: 0
Received 2 Likes on 2 Posts
pull that engine apart, rebuild it, and drive it, the experiance will be priceless. anyone can work on a **** engine, most ppl ive met hate rotaries because they are either scared or just dont know how to work on them
Old 11-21-05, 05:48 PM
  #14  
Junior Member

Thread Starter
 
sunflower4140's Avatar
 
Join Date: Oct 2005
Location: sc
Posts: 37
Likes: 0
Received 0 Likes on 0 Posts
ok i pulled plugs out and cleaned them, then re-adjusted throttle cable to see if i could get the idle right and that didnt help it none. could a new fuel pump and fuel filter make it run and idle better because it seems to be something to do with the fuel mixture. It still burns gas way too much and u can smell the raw gas. Somebody told me to replace the pulsantion dampner. Could that be it? May my fuel injectors need to sent off and cleaned? And i think i have an exhaust leak because when u drive it, when u apply the clutch and let off the gas to shift it makes and popping noise and the catilytic converters are gutted, i know that would effect my gas mileage a little but it shouldnt effect it that much. Could a hole in the exhaust system cause a lack of power and it to burn gas like that? So just let me know what u think?
Old 11-21-05, 06:27 PM
  #15  
Eats, Sleeps, Dreams Rotary

 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,732
Received 88 Likes on 64 Posts
check the FSM (download the Engine section online) and try the troubleshooting in there.
Old 11-21-05, 07:14 PM
  #16  
Junior Member

Thread Starter
 
sunflower4140's Avatar
 
Join Date: Oct 2005
Location: sc
Posts: 37
Likes: 0
Received 0 Likes on 0 Posts
what is fsm
Old 11-21-05, 07:23 PM
  #17  
Rotary Enthusiast

 
tjeter's Avatar
 
Join Date: Apr 2005
Location: NOVA, Calvert county, Charlotte
Posts: 980
Likes: 0
Received 0 Likes on 0 Posts
factory service manual.
Old 11-21-05, 07:30 PM
  #18  
Rotary Enthusiast

 
tjeter's Avatar
 
Join Date: Apr 2005
Location: NOVA, Calvert county, Charlotte
Posts: 980
Likes: 0
Received 0 Likes on 0 Posts
I would deffinently compression check that motor, i have to agree with the others it sounds like it may be shot, its not a vacuum leak, and the gurgling doesn't sound very comforting at all. Is there a local rotary shop near you?
Old 11-21-05, 07:40 PM
  #19  
PIMP

 
therotaryrocket's Avatar
 
Join Date: Feb 2004
Location: Greensboro, NC
Posts: 1,012
Likes: 0
Received 0 Likes on 0 Posts
gutted cats should increase your gas mileage for the better. when my turbo II had an exhaust leak at the bottom of the downpipe (when it was still stock), it lost a lot of power, but this was on a turbo engine so idk. sending off the fuel injectors for cleaning probably won't solve the problem, pulsation damper should work fine as long as it is not leaking. i would say replace the fuel filter, its regular maintainence anyways, and if it is clogged can cause a loss of power.
Old 11-21-05, 07:42 PM
  #20  
Junior Member

Thread Starter
 
sunflower4140's Avatar
 
Join Date: Oct 2005
Location: sc
Posts: 37
Likes: 0
Received 0 Likes on 0 Posts
RX-7 world is located in Rock Hill, South Carolina which is about an hour and a half from Greenwood, South Carolina which is where im from soooooooooo
Old 11-21-05, 10:08 PM
  #21  
round and round we go

 
linkage's Avatar
 
Join Date: Oct 2005
Location: Vail, CO
Posts: 12
Likes: 0
Received 0 Likes on 0 Posts
this sounds like what my 86 is doing i can smell gas when its running .. i did a compression test and the front rotor has fouled plugs but great compression... it sat for a while so far ive checked the ignition coils they were ok...... the bac sensor did nothing when i unpluged it so im toying with it ...there is a lead on modifying a regular compression tester if u search for it
Old 11-22-05, 02:56 PM
  #22  
Junior Member

Thread Starter
 
sunflower4140's Avatar
 
Join Date: Oct 2005
Location: sc
Posts: 37
Likes: 0
Received 0 Likes on 0 Posts
yea mine sat up for a while and i just checked the the wires with a spark tester and the wires are firing right and the plugs are fine so i dont think its my ignition, so im going to replace the fuel pump and fuel filter
Old 11-22-05, 05:13 PM
  #23  
Full Member

 
BigMike85's Avatar
 
Join Date: Mar 2005
Location: Alton, Godfrey, & Macomb IL
Posts: 231
Likes: 0
Received 0 Likes on 0 Posts
if you smell gas under the hood at all, I would replace the pulsation dampener.

Air escaping into the radiator and smoke on start-up sound like coolant seal.

Idle prob may be because of the BAC.

Last edited by BigMike85; 11-22-05 at 05:15 PM.
Old 11-24-05, 09:56 AM
  #24  
Newbie
 
orangezebra4612's Avatar
 
Join Date: Nov 2005
Location: Littleton, NC
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
Where is the fuel filter located on my 85 GSL carb engine?
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
streetlegal?
New Member RX-7 Technical
13
03-17-22 02:46 PM
Queppa
New Member RX-7 Technical
8
09-02-18 09:53 AM
stickmantijuana
Microtech
30
04-23-16 06:37 PM



Quick Reply: fuel economy sucks and lack of power



All times are GMT -5. The time now is 05:57 PM.