Rough idle with s/c

by **bunthy** » Mon Jan 02, 2006 9:54 am

Hey all,

So I have everything all connected correctly for the s/c. The ebc is connected correctly along with the new vacuum line route. I just put in the IAC check valve, so everything is connected.

The problem I have is that sometimes the car would be rough idling. Sometimes when I accelerate when in R, or when I'm coming out of a street and accelerate to the main street. When I let go of the gas pdeal in both situations, the car would start to chug, the rpm would bounce from 500 to 690 quickly, the lights dim, the exhuast pulsates and I'm freaking out.

I dunno what the problem could be. I've checked all the connections, everything is plugged. The only that isn't is the vaccum tank itself thats located in the firewall.

The chugging would go on for about 15-20s. I give it a little gas to get the rpm above 1000.

Any ideas of how to take this problem on? Any clue to what the problem is?

Thank in advance for the help guys/gals,
bunthy

by **DatSRBoi** » Mon Jan 02, 2006 10:47 am

Just might be idles too low. Try resetting the idle. What I did was started the car and repositioned the throttle line to 800rpm idle. I did this after the car was completely warm up and droven it for awhile.

by **bunthy** » Mon Jan 02, 2006 12:23 pm

yeah but the thing is that it would rough even after the car has been warmed up. Its really strange because it would do it every now and then.

It roughs to a point that the car wants to shut down but it doesn't. Its really frustrating when it does it when I'm pulling from the side street, where the car would seem that its not accelerating at all to instantaneously thrust forward.

by **Akfahad** » Tue Jan 03, 2006 7:56 am

You said the RPM's go up from 500 to ~690. My question is, do the RPM's stay up there or do they go back down to 500 and back up again? My car used to do that at times. Not all the time though and it worried me, same as you. However, after I had it tuned, I don't remember it happening again. What other mods do you have besides the supercharger? Have you upgraded fuel or anything like that? If you have, that might be the reason. Also, it could be a timing issue, just thinking out loud though.

by **bunthy** » Tue Jan 03, 2006 9:04 am

^

yeah the rpm would go up and down, up, down. I don't have any other upgrades, cept for a CAI.

by **Akfahad** » Wed Jan 04, 2006 9:07 am

Since you have the CAI, the MAF sensor could just be getting some messed up readings. If the supercharger, at stock psi I take it...right? and the CAI is all you have, I wouldn't really worry about it. That's just me though.

Josh

by **Assyrian** » Wed Jan 04, 2006 9:49 am

I don't know if this is an issue with solaras... but with my old car (mx6) guys would take multimeters to their throttle position sensors and check that too.

by **Fletch** » Wed Jan 04, 2006 9:52 am

I had a similar problem a while back. Using a scan tool, I root caused it to the throttle position sensor which liked to be a little slow to respond. Also found the rear bank upstream O2 sensor did not go from rich to lean in the closed loop (idling) mode. I ended up replacing both upstream O2 sensors and the TPS, the problem went away.

If you do not have access to a scan tool, take the intake off the throttle body and inspect how clean it is. They like to get quite oily on the 1mz. It's easy to clean with a rag and some carb cleaner or similar product.

BTW, the TPS was $50 and it's easy to do yourself.

by **Assyrian** » Wed Jan 04, 2006 11:58 am

good! nice to know that some of my car specific knowledge carries over to the solara.

by **smacd11** » Sat Feb 25, 2006 12:13 am

I just got my S/C installed and I didn't have the correct IAC check valve. I improvised with a GM PCV valve that looked like it would do for the moment. My car would idle around 500 rpm and the lights would dim. I went everywhere trying to find a check valve (didn't realize that little POS would be the hardest part of the whole install). After no luck and staring at my engine bay wondering what to do it dawned on me. There was one staring me in the face the whole time - on the brake booster hose. I finally found one at the wrecker in an old Celica and put it in. All my idle problems were fixed. Ny guess is that the PCV valve being a bit smaller in diameter didn't pass enough air to idle.

Back to my point - if you have the correct check vale installed try switching it around. Maybe it is checking the wrong way.

Shawn

by **CASTRO** » Sat Feb 25, 2006 12:21 am

i had a very similar problem where my car would not hold idle. IT would start sputtering and sometimes died. Check your EGR valve, it may be stuck. Thats what my problem was anyways. Another thign that solved my problem was brand new spark plugs. Sometimes they may need to be checked for gap clearance, but other times just fouled up from carbon deposits.

by **ruffrydasean** » Sat Feb 25, 2006 1:51 am

that's happened to me a few times before.. I'd be sittin at a light then the car would drop RPMs under 1k, start feeling kinda shaky and then just cut off

by **bunthy** » Sat Feb 25, 2006 7:32 am

smacd11 Posted: Sat Feb 25, 2006 3:13 am Post subject:

--------------------------------------------------------------------------------

I just got my S/C installed and I didn't have the correct IAC check valve. I improvised with a GM PCV valve that looked like it would do for the moment. My car would idle around 500 rpm and the lights would dim. I went everywhere trying to find a check valve (didn't realize that little POS would be the hardest part of the whole install). After no luck and staring at my engine bay wondering what to do it dawned on me. There was one staring me in the face the whole time - on the brake booster hose. I finally found one at the wrecker in an old Celica and put it in. All my idle problems were fixed. Ny guess is that the PCV valve being a bit smaller in diameter didn't pass enough air to idle.

Back to my point - if you have the correct check vale installed try switching it around. Maybe it is checking the wrong way.

Shawn

I'll check my lines again and the PCV valve too.

CASTRO Posted: Sat Feb 25, 2006 3:21 am Post subject:

--------------------------------------------------------------------------------

i had a very similar problem where my car would not hold idle. IT would start sputtering and sometimes died. Check your EGR valve, it may be stuck. Thats what my problem was anyways. Another thign that solved my problem was brand new spark plugs. Sometimes they may need to be checked for gap clearance, but other times just fouled up from carbon deposits.

I'll check the EGR too. As for sparks, I put in brand new IK22 when I installed the charger, only about 4 months now.

But I'll check the above mention and see if it helps any. Thanks. guys.

Rough idle with s/c

Rough idle with s/c

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