TB mod and idle problems
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Nipples
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TB mod and idle problems
Hey guys. I put on a smoothed out TB with the TB mod done. I put it on an 88 rx7. The thermo wax assembly is on still.
Now when I start the car...it BOUNCES at 1500~1800. The engine rpm bounces. BOUNCES!!!
What the hell. I replaced the TPS witht the same one that i took off. ( i ported a TB off a junk yard car, then swapped into the running one)
Also, there's fumes like crazy...like carbon monoxide. We are in a garage with the door open, but within 12 seconds we're gassed out. Its allot worse than other piston engines.
So anybody have an idea waht this issue might be?
-Grant
Now when I start the car...it BOUNCES at 1500~1800. The engine rpm bounces. BOUNCES!!!
What the hell. I replaced the TPS witht the same one that i took off. ( i ported a TB off a junk yard car, then swapped into the running one)
Also, there's fumes like crazy...like carbon monoxide. We are in a garage with the door open, but within 12 seconds we're gassed out. Its allot worse than other piston engines.
So anybody have an idea waht this issue might be?
-Grant
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Could be a vac leak, out-of-whack TPS or simply the idle is set too high. If you set it too high the ECU tries vainly to lower it using the BAC valve, causing the hunting. Disconnect the BAC valve and it should stop hunting. Use the idle speed screw to lower the idle to ~600rpm. Plug the BAC valve back in and it should hopefully sit at a steady 750rpm. Make the sure the TPS is set correctly (engine hot).
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Re: TB mod and idle problems
Originally posted by I Hate Ricers
Its allot worse than other piston engines.
-Grant
Its allot worse than other piston engines.
-Grant
Heh, for the co2 smell... all I can say is get a different car or get used to it. Once you mod an rx7, you will never get rid of the fumes. Prepare them to leach into your clothing, your bed, ect.
And you did the tb mod, you should have been expecting idle issues. Rerun the TPS, adjust the idle adjust screw, adjust the secondary stop screw. My idle was around 200rpm after the TB mod. It took me two weeks to get a decent idle. I had to adjust the three above things, rerun some vac lines, ect.
goodluck.
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Nipples
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Why do i have to set the tps though? I'm using the same one as before. I'm afraid that might be my problem too.
I turned the idle adjustment screw all the way down as far as it goes and the idle was still too high.
Are all the fumes because the rotary is running too rich now?
One thing i noticed is with the TB i put on, the double flaps (there's a single, then a double below it...not sure which is primary, secondary etc.) have more of a gap then the one i took off. I can see this letting in more air making the idle too high.
Any suggestions on where i sohuld go from there?
-grant
I turned the idle adjustment screw all the way down as far as it goes and the idle was still too high.
Are all the fumes because the rotary is running too rich now?
One thing i noticed is with the TB i put on, the double flaps (there's a single, then a double below it...not sure which is primary, secondary etc.) have more of a gap then the one i took off. I can see this letting in more air making the idle too high.
Any suggestions on where i sohuld go from there?
-grant
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ok you say you used the same one as before, that doesn't mean it is set.. The tps itself is the same but the position of the "set screw" is not. You probably just need to set the stupid tps set screw.....try that then come back.
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Nipples
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would pulling the tps assembly off, then pushing the button or letting off while it's connected electrically show if the TPS is the culprit?
I don't know if I should be adjusting the TPS screw closer or farther away.
Actually, I think i need to just pull the TB off and look at why the secondaries aren't closing fully.
I don't know if I should be adjusting the TPS screw closer or farther away.
Actually, I think i need to just pull the TB off and look at why the secondaries aren't closing fully.
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Nipples
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Hey, i took it out for a drive with all the running problems.
Here's what i encountered:
The car would die ever 15 seconds, even while the rpm was bouncing...which was in fact the BAC valve. I plugged it back in after knowing why the rpm was bouncing. The RPM would try to stay high...like 1500 rpm. I jsut drove like that anyhow.
After a few minutes of driving though...the car runs perfectly!
I am therefor thinking that the idling problems has something to do with a cold start thing. I'm not really sure how mazda's set up works, but I'll look through the FSM.
Anybody know what might be giving me the cold running issues?
-Grant
Thanks for all the help so far you guys. It has been very beneficial. I love this forum!
Here's what i encountered:
The car would die ever 15 seconds, even while the rpm was bouncing...which was in fact the BAC valve. I plugged it back in after knowing why the rpm was bouncing. The RPM would try to stay high...like 1500 rpm. I jsut drove like that anyhow.
After a few minutes of driving though...the car runs perfectly!
I am therefor thinking that the idling problems has something to do with a cold start thing. I'm not really sure how mazda's set up works, but I'll look through the FSM.
Anybody know what might be giving me the cold running issues?
-Grant
Thanks for all the help so far you guys. It has been very beneficial. I love this forum!
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Check your thermosensor, see if it is plugged up and making a good connection. (psst.. i still say tps need adjustment...) cough.....The thermosensor is the green connector on the rear of the coolant filler neck.
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