nruri

Hey Guys

In order to fix my bad idle problem I was told to replace all the vacuum hoses and make sure there are no leaks

Well I finally finished replacing the hoses and put intake manifold back on, bolted everything up ...
Well the car is not worse off

It also sounds like it backfiring and such
It also doesn't not IDLE at all
And being constantly on the throttle holdit at 3000rpm the rpm just drops and bounces...

I also replaced the gaskets with new ones and such..

Guys I don't know what's wrong..
ANyone have anything?

I'm scared that the engine may be permenantly screwed.
I haven't even had a chance to really drive my 7 after buying it...

All help appreciated thanks.

1986 NA GXL if it's important.

- Shawn

poor college student

compression check....?

poor college student

btw, have u changed ur plugs/wires...? mine were totally shot, and my car wasn't idling well either.... doesn't sound as bad as urs... but maybe ur plugs are worse than mine.... even tho both my leading electrodes were burned off...

nruri

The plugs and wires are new

One more thing though
I can really smell gas when i start and run the engine
I'm also guessing that the car is also running lean...

How do I go by doing a compression check?
Just any compression check tool?

Thanks
- Shawn

Aaron Cake

iTrader: (1)

Sounds like you messed something up when you were changing the hoses. So many possibilities, but I would first check for huge vacuum leaks, then check to make sure the injectors are properly connected. If you smell fuel, it may be misfiring, so it's time to make sure all the plugs and wires are fine, as well as in the proper order.

nruri

Alright,

I guess it's back to checking the hoses again.
If it's not the hoses it could be the injectors...

Should I bet getting something for the injectors? (o-ring or something?)
I checked for fuel leaks because i really didn't want that.

So it could be a huge leak...
What about the connectors? There were like 6 or 7 that I disconnected. I don't think I would have messed any of those up.
Except maybe the 4 connectors behind the Alternator?
Were the 2 sets of connectors look exactly the same but different colours?

One questions about the vacuum hoses
Could I have mixed up a connection of the vacuum hoses?
Like put one end on one part but the other end on the wrong line?
I really dont' think i did for anything what needed to be connected.. but now I'm worried that i may not have connected the lines properly to the intake manifold.
Thanks,
-Shawn

hypntyz7

#1 rule of troubleshooting a rotary. Compression check.

Here is a writeup, one day it may be posted on my webpage.

Rotary Engine Compression Check

Often people chase after problems with their RX-7 for many hours, even weeks at a time. My first rule of troubleshooting a rotary engine is to first perform a compression check. IF this reveals no problems with the short block/internals, then a control system or condition is at fault. I have looked at, worked on, or purchased many 7’s which had blown engines, all the while the pervious owner thought there was a fuel pump, fuel filter, sparkplug, coil, computer, etc. problem causing the car not to run properly. Here are steps to performing a compression check with or without a tester.

Poor Man’s Compression test(free):

1. remove lower sparkplug and wire from front rotor.
2. remove EGI fuse from underhood fusebox to prevent fuel and spark while testing.
3. have an assistant crank the car over for you, while you listen under the hood at the compression pulses coming from this plug hole. IT is recommended to put your hand/finger right in front of the hole to feel the pulses of air.
4. There should be one strong pulse/whoosh of air per full rotation of the crank pulley. Use the timing marks on it as a reference. There should be 3 even pulses in succession, without skips or gallops.
5. IF one or more pulses are weaker or non existant, this indicates (usually) at least one blown apex seal and severe internal damage. A full rebuild will be required, and no further troubleshooting will help.
6. IF this chamber passes the compression test, replace this plug and repeat for the rear. The rear rotor blows more often then the front on 88 and prior engines, and the front rotor blows more often on 89 and later engines, for reasons unknown.
7. With both lower plugs out at one time, you can listen/feel for compression on both rotors at once. This should be a rhythmic ch-ch-ch-ch-ch-ch sound, like an old steam engine train, alternating front to back, once per rotor per rotation. Any skips or galloping indicate loss of compression.
8. note that this procedure can be used to test junkyard engines or engines out of the car. You will need a 19mm socket and ratchet to turn the front crank pulley bolt clockwise in quick, long strokes as possible to get a somewhat accurate reading. You will obviously not be able to turn the engine much at a time, so try to count each pulse as you go.


Compression test using a piston engine tester:

1. note battery strength. A weak battery will yield low compression results.
2. Remove both lower plugs and wires.
3. remove EGI fuse from engine fusebox.
4. have a friend floor the accelerator pedal, opening the throttle for more airflow
5. insert your tester into the leading hole
6. hold the valve on the side of the tester open
7. have your friend crank the car over for 5+ seconds.
8. observe the needle bounces. You should see 3 in succession without skips, even bounces, in roughly the 30-35psi range.
9. let out on the valve now, and let the tester reach an overall compression value for all 3 faces(highest of 3 will be displayed). 115+ is like new, 100-115 is healthy, 90-100 is getting weak(1 year or less in most cases) below 90 could blow at any moment.
10. repeat for opposite rotor. Note difference in overall compression between rotors, which should be no more than 20psi max.

nruri

Alright!
Niceness
Thank you very much
I'll check the compression the poor mans way for now.
I really hope it isn't blown...
I'm not liking the Idea of having to get an engine rebuilt without even getting a chance to drive the car a full day.

If it is blown... I don't even know who rebuilds rotary's in my area (GTA, Canada, Ontario)

-Shawn