Lower RPMs during Idle and Driving.

[stock1g4g63]

I was cruising down the hwy in 5th, when all of a sudden the RPM's dropped all the way down to about 1-1.5k. The car was a little weak, but I could still drive back home with a great loss of power. At idle, it's right around 1-200 rpms, really really low. And I could still move it around, but can't really drive it normally. MAS air seems ok, no blown intercooler piping. I have to floor the gas pedal to get the car to move around at only 1-2k rpms in any given gear, while the A/F ratio is right around 19.0 - 20. I can't seem to figure it out. Please advise, because I just bought an external wastegate yesterday, and haven't even gotten a change to put it in yet.

 

[stock1g4g63]

Could it have anything to do with the hot weather? I just tried to start it, and it started up and idled fine, but I've yet to drive it yet. I'd rather let it sit for a little while longer.

 

[donmagicjuan]

- That's a bump in sheep's clothing if I ever saw one. It sounds like your engine is getting a ton of air that isn't being metered with those AFRs. If you've done a boost leak test that didn't turn up anything, check the connections to the intake pipe. Also, how does the car sound when it's doing all of this? Is it running smoothly, or does it sound like it's falling on its face? More information would probably help a lot with a diagnosis.

 

[stock1g4g63]

Ok, it just happened again, so once again, I turned off the car, waited 30 min, and it started right back up. Like last time, with the pedal almost floored, I'm barely moving, and the car is a little "stumbly" and feels like it's bogging, but AFR shows 19-20. I don't have anything to do a boost leak test with as of right now, but I disconnected the battery and let the ECU reset, hoping that it will help the problem. Also, tomorrow is the MOD 06 meet, so maybe someone there can look at the problem and help me solve it if it shows up again.

 

[stock1g4g63]

Ok, reset the ECU, same problem. Could it be the fuel pump? It's really starting to agitate me, and I can't figure it out for the life of me. The car sounds like a lawnmower, sputtering, but consistent, fast sputter. When I turn it on, it sounds exactly like when you pull the string on the lawnmower to try to start it, and I need to give it some gas or it won't come on.

 

[donmagicjuan]

Are you getting a CEL? If you know how to 'read' your spark plugs, take a look at them and post the results.

 

[stock1g4g63]

Found the problem, hopefully. It's the TPS.

 

[donmagicjuan]

Found the problem, hopefully. It's the TPS.

Well that would do it. Definitely search ebay/wrecking yards first. I just had to buy a new one and got it for less than $20. Just in case they don't have the part # at a junkyard, the following cars all used the same one (sorry the list is long):

1999 MITSUBISHI

Eclipse Spyder L4 4G63T 2.0L VIN=F

Eclipse L4 4G63T 2.0L VIN=F

Galant L4 4G64 2.4L VIN=G

1998 EAGLE

Talon TSI L4 2.0L VIN=F

1998 MITSUBISHI

Eclipse GST L4 4G63 2.0L VIN=F

Eclipse GSX L4 4G63 2.0L VIN=F

Galant DE L4 4G64 2.4L VIN=G

Galant ES L4 4G64 2.4L VIN=G

1997 EAGLE

Talon TSI L4 EGB 2.0L VIN=F

1997 MITSUBISHI

Eclipse GST L4 4G63 2.0L VIN=F

Eclipse GSX L4 4G63 2.0L VIN=F

Galant DE L4 4G64 2.4L VIN=G

Galant ES L4 4G64 2.4L VIN=G

1996 DODGE

Stealth V6 3.0L VIN=H

Stealth R/T V6 3.0L VIN=J

Stealth R/T Turbo V6 3.0L VIN=K

1996 EAGLE

Summit DL L4 1.5L VIN=A

Summit ES L4 1.5L VIN=A

Summit ESI L4 1.5L VIN=A

Summit DL L4 1.8L VIN=C

Summit ES L4 1.8L VIN=C

Summit LX L4 1.8L VIN=C

Talon TSI L4 EBG 2.0L VIN=F

1996 MITSUBISHI

Eclipse GST L4 4G63 2.0L VIN=F

Eclipse GSX L4 4G63 2.0L VIN=F

Galant ES L4 4G64 2.4L VIN=G

Galant LS L4 4G64 2.4L VIN=G

Galant S L4 4G64 2.4L VIN=G

1995 DODGE

Stealth V6 3.0L VIN=H

Stealth R/T Sport V6 3.0L VIN=J

Stealth R/T Turbo V6 3.0L VIN=K

1995 EAGLE

Summit DL L4 1.5L VIN=A

Summit ESI L4 1.5L VIN=A

Summit DL L4 1.8L VIN=C

Summit ESI L4 1.8L VIN=C

Summit LX L4 1.8L VIN=C

Talon TSI L4 EBG 2.0L VIN=F

1995 MITSUBISHI

3000GT SL V6 6G72 3.0L VIN=J

3000GT Spyder SL V6 6G72 3.0L VIN=J

3000GT V6 6G72 3.0L VIN=J

3000GT Spyder VR-4 V6 6G72 3.0L VIN=K

3000GT VR-4 V6 6G72 3.0L VIN=K

Eclipse GST L4 2.0L VIN=F

Eclipse GSX L4 2.0L VIN=F

Galant ES L4 4G64 2.4L VIN=G

Galant LS L4 4G64 2.4L VIN=G

Galant S L4 4G64 2.4L VIN=G

Mighty Max SWB L4 4G64 2.4L VIN=G

Mirage ES L4 4G15 1.5L VIN=A

Mirage S L4 4G15 1.5L VIN=A

Mirage ES L4 4G93 1.8L VIN=C

Mirage LS L4 4G93 1.8L VIN=C

1994 DODGE

Stealth V6 3.0L VIN=H

Stealth R/T Sport V6 3.0L VIN=J

1994 MITSUBISHI

3000GT SL V6 6G72 3.0L VIN=J

3000GT V6 6G72 3.0L VIN=J

3000GT VR-4 V6 6G72 3.0L VIN=K

Eclipse GS L4 2.0L VIN=F

Eclipse GSX L4 2.0L VIN=F

Galant ES L4 4G64 2.4L VIN=G

Galant LS L4 4G64 2.4L VIN=G

Galant S L4 4G64 2.4L VIN=G

Galant GS L4 4G64 2.4L VIN=L

Mighty Max L4 4G64 2.4L VIN=G

Mirage ES L4 4G15 1.5L VIN=A

Mirage S L4 4G15 1.5L VIN=A

Mirage ES L4 4G93 1.8L VIN=C

Mirage LS L4 4G93 1.8L VIN=C

1993 MITSUBISHI

3000GT SL V6 6G72 3.0L VIN=J

3000GT V6 6G72 3.0L VIN=J

3000GT VR-4 V6 6G72 3.0L VIN=K

 

[TruElegance]

I was having the same problem, so Im going to check out my TPS and see if thats it. Hopefully it helps.

 

[stock1g4g63]

Wow, thanks for the list! That's really helpful!

 

[stock1g4g63]

Wait, if my TPS is out, would my AFC still be able to read my throttle accurately? It still seems to read accurately what percentage my throttle is pushed in at, so I'm looking at the problem again.

 

[95talon_in_ma]

Sounds like your timing belt might have jumped a tooth.
If the other things check out, pull the cover and align the marks and see what you get...

good luck!

 

[stock1g4g63]

Would that cause the car to go in and out of commission the way it does? I mean, it drives fine sometimes, and sometimes not.

PS Thanks for all the help guys. I can always count on DSMtuners

 

[95talon_in_ma]

Would that cause the car to go in and out of commission the way it does? I mean, it drives fine sometimes, and sometimes not.

Nah, It would be like that all the time...

Did you do all the idle fix stuff?
http://www.dsm.org/how-tos/tttt/tttt3.html

I know it says it's for fast idle, but chances some of the stuff mentioned could benefit you...