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N/A Chugging Cont (with video)

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Old May 16, 2007 | 04:37 PM
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Question N/A Chugging Cont (with video)

Ok seriously the car is like feels like jekyl and hyde.

Maybe once out of 50 times from a complete stop the car does not chug, ive tried leaning it out, im scared to lean it even more until my air / fuel guage arrives.

Here are two short (less than 10 sec each) videos of me trying to put my foot on the floor. Perhaps it will help a little more, and maybe someone will recognize my problem.

N/A Chugging Clip #1

N/A Chugging Clip #2

PS. turn sound on in order to hear the 'chugging' please excuse any profane language coming from the passenger seat :-P (minor profanity)
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Old May 16, 2007 | 10:05 PM
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Easy speed demon!

Check ALL your mounts. Engine, Transmission, differential.

Sounds like some of your mounts are no good, as in, broken in half.

Also, how is your rear struts? All these little things can play a large part in the issue you are having. Mine does the same except not as bad. I have bad transmission mounts and my rear diff mount looks weak. Engine mounts are new Mazda Comps.
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Old May 17, 2007 | 12:23 AM
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are all of the coils and igniters working because I noticed your tak isnt working.
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Old May 17, 2007 | 01:30 AM
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Hmmm.

Make sure you have your spark wiring correct. Also check timing.

Have you done a compression test?

I don't think your tach not working would effect anything performance wise.

So, it chugs the same regardless of throttle position?

It seems to me like maybe the spark isn't kicking at the right time. And as the RPM gets up there and the timing advances, it gets a little smoother. Double check timing. Make sure you are lining up the leading coils with the mark that is on the far right, not the one on the left.

FSM has information on setting timing statically and with a light.

My GF car was doing that, but hers was a bad fuel pump. Hers also detonated a lot... not an RX-7. Otherwise there wouldn't been a broken motor....

Also, if you have an air compressor, check for vacuum leaks. You can also use starter fluid to look for leaks.

Timing is all i can think of. Though, it generally doesn't stop working on its own.

Maybe your coils are going bad, or something like that....

Good luck. Let us know if you figure something else out.
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Old May 17, 2007 | 08:39 AM
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Originally Posted by Rx7TyreBurna
Hmmm.

Make sure you have your spark wiring correct.
checked, good.

Originally Posted by Rx7TyreBurna

So, it chugs the same regardless of throttle position?
No, If i give the gar VERY VERY LITTLE throttle, it will run very smothely (obviously with no power) and the higher the rpms get the more it throttle it allows me to give.

If i put my foot all the way down, it chugs.

Originally Posted by Rx7TyreBurna
It seems to me like maybe the spark isn't kicking at the right time. And as the RPM gets up there and the timing advances, it gets a little smoother. Double check timing. Make sure you are lining up the leading coils with the mark that is on the far right, not the one on the left.
FSM has information on setting timing statically and with a light.
I havent checked the timing, I was tought in mechanics school but that was a while ago, when i have a day off work i will try and figure it out, or bring it to a garage to check the timing.

Originally Posted by Rx7TyreBurna
Maybe your coils are going bad, or something like that....
Hmm, A bad trailing coil will make my tach not work right? maybe this is the problem.

Does anyone know where to buy new coils?

See also the thing is, some days it will let me put my foot all the way down. However when it lets me it dosent put the power out, its as if im only giving it
1/4 throttle. And other times it chuggs like in the video. I honestly think it has something to do with the weather? cause it runs alright (still balless in low rpm) when its a nice cool crisp night. When its really humid / hot / rainy it chugs. maybe its just a matter of tuning?

Last edited by ziplock; May 17, 2007 at 08:50 AM.
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Old May 17, 2007 | 08:50 AM
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just buy used ones, they usually last forever it's rare that they go out, check your grounds for them
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Old May 17, 2007 | 08:51 AM
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whats that beeping thats a new one to me
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Old May 17, 2007 | 11:47 AM
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A bad trailing coil will not make the motor chug. It will effect performance though.
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Old May 17, 2007 | 12:09 PM
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I'd probably say it's an ignition issue.
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Old May 17, 2007 | 12:12 PM
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Turn off the A/C....
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Old May 17, 2007 | 12:16 PM
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I would start with the tach not working... But my 87 did this too, It was a clogged fuel filter......... I replaced the strainer in the tank and the filter...
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Old May 17, 2007 | 05:19 PM
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A/C wouldnt make the car chug like that, never the less, it wasnt on.

Doubt any motor mounts would either, as they seem are fine.

The beeping is my power steering computer telling me that my tach dosent work, most probably related to a coil issue, however it dosent make sense that the car would chug like this due to a coil at 1/4 throttle @ low rpms, and its fine at full throttle at high rpms. Unless it advances itself or something as someone said. I have no idea how 'timing' works on this car going to read about it.

anyways i have tomorrow off, I will check read up on how to and check the timing, and ill check in with you guys then.

Cheers
Zip

Last edited by ziplock; May 17, 2007 at 05:27 PM.
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Old May 17, 2007 | 09:04 PM
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I highly doubt its an ignition issue, if his trailing coil is not working, then he does not have as much power which will aggravate the main issue which is the chugging which will occur when you have bad mounts.

Motor mounts would cause this and you need a different answer then "they seem fine". Support the engine from underneither and remove them to inspect them. Do this with all your mounts and I bet you will find 1 or more mounts that are bad or weak

Mine does this too, like I said just not as bad.
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Old May 17, 2007 | 09:54 PM
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seems to partially clear up in higher revs, i knwo it still does it but not as bad... possibly a porlbme with the main set of injectors since it seems when the second ones come online it gets better.
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Old May 17, 2007 | 10:05 PM
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My 88 RX-7 likes to chug mildly at higher rpms.....no idea what causes that. And sometimes it idles really low, and stalls.
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Old May 17, 2007 | 10:45 PM
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Ok guys, put a bottle of STP injector cleaner and half a tank of gas,
I leaned the **** out of the car, well, allowed more air into the car via
the bypass on the upper manifold, and its running ALOT better.
It only chugged about twice driving for over 2 hours.
There was more power and torque than its ever had in my hands so far.

Im bringing it into the garage tomorrow to have the mounts checked properly, however
from my experience mounts would only have such a big 'chugging' effect on a manual transmision.

Will check my grounds and timing tomorrow, gonna buy a timing light and a digital multimeter.

Will keep you guys posted.

Cheers
Zip

Last edited by ziplock; May 17, 2007 at 10:56 PM.
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Old May 18, 2007 | 12:05 AM
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well the tach Operates off the the Trailing,so If you happen to have anything related to the trailing NOt firing then you would have Poor Performance.I would check the Plugs,the Trailing Plugs.If they don't fire the Tach sees Nothing.so it Doesn't work.Also get your Fuel filter changed out.You would be suprised what a New one can do for you.NO more Trying to Get gas when the filter is plugged when you floor it.It may Go good as long as you don't Mash the pedal but once the car Needs More Fuel then the Crud in the filter Cuts the flow and Bogs the car.
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Old May 18, 2007 | 08:25 AM
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I leaned the **** out of the car, well, allowed more air into the car via
the bypass on the upper manifold
You talking about the Bypass air control valve?

however
from my experience mounts would only have such a big 'chugging' effect on a manual transmision
Could still happen but you are right. I didn't take into account that you may have an auto tranny.

Your chugging sounds like a bouncing chug not an ignition skip which you would hear in the exhaust tone. This is why I say it may be your mounts. IF your trailing is not firing then like I said above, may be aggravating the issue that you never really noticed before.

Hope you get it fixed! My slight chug annoys the hell out of me if I hit the gas to hard. If it was as bad as yours, I would park the car and use something else
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Old May 18, 2007 | 08:32 AM
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Reminded me of the Blair Witch Project.

I would get your trailing coils working correctly.
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Old May 18, 2007 | 08:36 AM
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hmm i'm starting to think maybe he's got dirty primary injectors
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Old May 18, 2007 | 11:17 AM
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Originally Posted by RotaMan99
You talking about the Bypass air control valve?
If you mean the screw above the intake manifold that allows more air to flow into your a/f mixture, yes. That is what i used to lean the car and it ran so so so so much better.

I am also running a high concentration of injector cleaner through this tank of gas.

Im off today to do a fresh oil and filter change, purchase a multimeter and a timing light.

I would love to do the fuel filter, having some trouble finding where it is via searching. IS it in the trunk or can i only acccess it via lifting the car?

As well guys take in to consideration my cats are blocked to all living hell, and are going to be removed (dont think my aux ports are even working anyways)

Updates to come
Cheers
Zip
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Old May 18, 2007 | 11:22 AM
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Fuel filter is on the drivers side towards the bottom of the car at the firewall.

Good luck! Hope you get it worked out.
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Old May 18, 2007 | 11:24 AM
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Originally Posted by My5ABaby
I would get your trailing coils working correctly.
could you maybe link me to a procedure on how to do this?

I mean, I put a spark plug tester between the plug and the wire and i have spark, maybe its not strong enough?

How do i check the coil?

Cheers
Zip
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Old May 18, 2007 | 04:22 PM
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If you mean the screw above the intake manifold that allows more air to flow into your a/f mixture, yes
Above the intake manifold? On the throttle body? The BACV is on the drivers side of the intake manifold. I noticed you have a Series4 N/A so I don't think there is a screw on the BACV, only on turbos. So you must be talking about on top of the TB?

You must have raised your idle doing this? Im still trying to figure out what and where you adjusted.
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Old May 18, 2007 | 04:23 PM
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Ok brought the car to the garage today, they told me that they checked ALL of my mounts and they are good but a little soft and they arent sure if thats how they should be, however all four stabalizer linkages are shot. They called for the part and they said I have to get them from mazda.

Anyone know about this. Could that be my problem?

I changed the oil, oil filter and fuel filter today. Its noticably smoother however, still chugging ever so slightly from stop in very low rmps. I am able to give it much more throttle now however, from dead stop with at least 1/2 throttle she still chugs as you ve seen in the video. Still havent checked timing, not really 100%on the procedure.

Point is, its not due mounts, oil, filter, gas filter, plugs, or wires, thus far. ...workin through the list :-)
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