hello All-
First time posting, and would greatly appriciate any and all help. I have recently picked up a 1984 GSL with the 12A. It was sitting for about 4 years as far as I can tell. I have "nursed" it back to life. I have it running and driving, just not so good. Fortunately, here in the Northwest things don't rot or get a lot of dryrot, so I am not overly concerned with things like vacume hoses. Anyway, here is the issue. It runs and sounds good, but doesn't rev up as easyily as it should. It takes a bit of effort to get it to and just above 4000 RPM. When it does rev up, there is a sort of whining sound that gets louder as the rev's come up. I can drive it around the block, but definately feels like something is holding it back. I have checked the compression, cleaned the carb, new plugs, cap rotor, and wires. What else can I check? Any help would be terrific! Thanks -

 

Try changing the fuel filter.

 

Thanks-
Forgot to mention I changed that too. Could it be the timing? I realized that I hadn't checked that yet. Could that be the issue?

 

Good chance that you've got some crud in the jets after sitting that long. Search for "toothpick" and you'll find a way to pull the jets for cleaning without tearing the entire carb apart. If you have time for a full carb rebuild, then do that though.

But before anything else, it might be worthwhile to run a can of seafoam through a partial tank (1/8 - 1/4) of gas. The stuff can work wonders sometimes. Good luck.

 

Thanks- Much appriciated. Where can I find "seafoam"? Local parts stores? I will search the toothpick and give that a shot too. Would the jets make the whining sound I hear while it runs?

 

Yeah any parts store should cary it, it will literally say Seafoam on it. Anytime of Lucas fuel treatment would work as well. What were your numbers on compression?

 

I picked up a basic compression tester at harbour Freight. With a cold engine I got 45. I wasn't sure if that was very good so I also tried the trick of pulling the trailing plug and turning over the engine, listening to the sounds. I got 3 strong and all even "whooshes" from each rotar. From what I had read from a differant thread was that was another way to tell if all 3 apex seals would be good. A bad seal would make a differant sound or none at all. Is this correct? Thanks again for all the advise.

 

you need a rotary specific compression tester to give accurate compression readings. I think someone had figured out a roundabout way to get a notion of an idea of close to the possible estimated guesstimations of compression from piston compression readings, but to get real values, you need a rotary specific tester.
Good looking out and saving a rotary.

 

This might be "help" the problem too:

https://www.rx7club.com/1st-generation-specific-1979-1985-18/common-cause-power-loss-nikki-carbureted-models-632007/

+1 for Seafoam. You can find it at NAPA and most good Auto Part Stores.

+1 for fuel filter and the air filter.

Have you changed the oil as well? During your next oil change put a qt. of Lucus Oil Treatment.

Might want to check the battery too. If you haven't already, put extra ground wire coming from the negative battery terminal to your one of your bolts on the strut tower. That might help give you a little extra power for a better spark. Might also want to change out the fusable links.

Explain the whining sound a little more. I am curious, are the belts too tight? Do you have A/C installed?

 

i had a similar problem when i still had the catalitic converters

 

i'm calling clogged cat as well. Unbolt your manifold from your exhaust, put some ear plugs in, and run it around the block to see if that frees it up. Also, SeaFoam works wonders.

 

Here's a thread talking about the problems w/ a regular compression tester

https://www.rx7club.com/1st-generation-specific-1979-1985-18/my-compression-numbers-676327/

 

When performing the ghetto compression test, on a bad engine it will sound like one rotor is pulsing at 3x the rate of the other rotor. If they both pulse at the same rate, you either have a good engine or both rotors are bad (not likely).

I got to hear one (with a bad apex seal) for the first time a couple of months ago. We thought the engine was fine, until I noted that the frequency of pulses was different between the two rotors. Not the greatest news for the owner of the car...

 

Thank you for all the good advise. This site is a great help! I had thought of the cat converter earlyer, and simply put my hand over the exhaust. There is lot of volume of exhaust comming out. Could the cat be plugged and still let that much thru? As far as the sound I hear, the best I can describe it is like the sound of the fan when the clutch is engaged, but at a higher pitch. As I rev it up, the sound gets higher. I have checked all the vacume lines and they look good. Part of my problem is it has dosn't idle, I have to keep my foot in it, to keep it running. I can hold the revs at 1000 with my the gas pedal, and it sounds good, just won't idle on it's own. I had thought carb issues and didn't want to start "tweaking" things quite yet. This has made finding the sound a bit hard. I want to thank everyone again for all the advise.

 

K Update-
Looked at timing and it was just a tick off. adjusted now good. I looked at the cause of the noise I hear. Thought maybe the ac, as the belt was very tight. Removed the belt and fired up the engine. Noise still there. To be more spacific, you really can't hear the noise at idle or below 2500 RPM. Its when you rev over say 3000, and on the downward RPM's you hear the noise. It is like a electric motor that tops out at say 3000 RPM's. Any of this sound farmiliar to anyone? Not sure what to try next. Anything you guys and gals can think of???

 

If she is not idleing then check the shutter valve hose. When you remove the air cleaner you will see a large diameter hose that is on the driverside portion of the engine and goes just below the carb. This is a common problem and will cause the noise and some of your symptons.

Also verify for the power loss that your secondary linkage has not popped off of the carb and you are just running on primaries.

 

Seeing if I had some pictures of the secondary linkage.

On the right side of the picture(alittle fuzzy) you can see a rod with sort of a t-handle to it. If that rod pops off then the secondaries will not open. This is a very common problem.

To recap the list of things that can cause your problem.

Low compression.
Clogged fuel filter or flow from the tank. (Pull inlet hose off fuel filter and check for flow).
Low fuel volume caused by the above. (Perform fuel volume test)
Clogged or partially clogged catalytic converter. (Remove exhaust before cat)
Only firing on the trailing ignition only. (verify with timing light or spark test on leading ignition)
Secondary linkage for carburetor not attached.(See attached picture)
ACV gasket blown and also will cause no idle and noise sympton.( spray wd40 around area while engine running)
Shutter valve leaking. (test per 1st post I have listed)
Forgot to add Kenetsu's recommendation about the jets being clogged. (either perform toothpick procedure, or easier to start with the Seafoam additive)

 

What would he be checking though? My car idles fine until that hose starts sucking in air and its loud then my engine sounds like its running on one rotor.

Sorry for the hijak

 

That whinning sound could also be a loose main belt ... the one off the alternator. All you need to do for that one is just pull up the alternator a tad more. It might be easier to locate the sound if you grab a long screw driver, or a craw bar or something and place it on each individual part and listen where the whine comes from.

Back about seafoam though, one thing I would do if I were you, pour about 1/2 the seafoam can through the carbs, and using a ratchet or hand (might be too hard sometime to do by hand) and turn the engine counter clock wise. I'd say give it a few sping with the ratchet (like 20 or so) to ensure the seafoam is being spread all over the place.Then let it sit for 1/2 a day, turn the engine over 180 degrees for the other half of the day to let both sides kinda soak in there. Next dat, take out the plug and dry them out and fire it up. It will smoke alot, but don't be afraid its just the seafoam coming out and doing it wonderful job.

 

Not a hijack, a valid question. :-)

When the shutter valve goes it is sucking vacuum all the time. What you described is the normal operation thru the emission system controlled by the solenoid. The vacuum leak causes the no idle. The shutter valve leak will be heard as a sort of honking noise..

 

K everyone, thanks to rx7doctor, I have made some progress on finding out what is wrong with my 7. I have found that the Air pump was the cause of the whining sound I heard. I removed the belt from it after hearing the sound come from the passenger side of the air filter. I believe it was from the check valve to the air cleaner. Question for everyone, what are the downsides of not re-connecting the Air Pump? Right now, it runs exactly the same as before, now just quieter and will rev up a bit more than it did. With help from the good Doctor, I have found that there is little spark on the Leading coil. I tested each of the 4 plug wires with my timing light and there is enough to fire the light. I did also put the timing light on the coil wires to the Dist and found that they would too light my timing light, but not nearly as bright. I measured Voltage to each of the coils, and only measured 2-3V at each coil. The car runs, and runs only on Trailing spark, which I understand tells me the compression is good. Anyone have some advise on whether 2-3V at the coils will let the car actually run? BTW, this forum has been GREAT! Thanks to everyone, especially the "Doctor" for all your help in bringing my 7 back to life.
James-

 

Well all, the shutter valve was the main reason for my power loss. I plugged the vacume hose and she is running like a, well, you know, awesome. I got this car thinking I would have to tear the engine out and rebuild it. It wasn't running at all when I bought it, and now she runs great. After a few trips around the block, it was running good enought to have a little fun, and she lit the tires on dry pavement for a long ways. Felt great! Thank you all for all your help, especially RX7doctor!

 

ya, docs the man. love hearing people bringing 7s back to life. god bless

 

Glad you got her running right. Don't forget to get some Seafoam for the fuel tank. This will just help clean out the system.

Put it in with about a 1/4 tank of fuel and run her until shes almost out.

Forgot to add. Since you are still running the Catalytic converter you need to put the air pump back on. If you don't, the catalytic converter will be destroyed and you will be back to a power loss problem again.

 

I was wondering about the Air Pump, if I really needed it or not. I will hook it up again, but if I get a header and a cat replacement straight pipe, will the Air Pump still be needed?

I have owned several 7's over the years, and my last one about 8 years ago. A sweet 88 black on black conv. I also had an 86 2+2 I autocrossed with in the Midwest. Always loved my 7's, but this 1st gen really means a lot to me. Guess cuz it was headed for the junkyard and, with all your help, have it back up and running. I will post some pics as soon as I get her cleaned up a bit. She is a little camera shy right now.

Thanks again all- joining this has been more than worth it!!!!!