SnOwY22

OK guys I've been searching non stop to know what my problem would be. My SC400 has non stop hiccups when doing a cold start. I let it sit for about 10 minutes and once it is warm and up to temp, the car runs fine. If I dont let it sit the whole 10 minutes to get it warm, once I go to give it gas, it will start hiccuping without lowering my RPMs, at idle it will sit at 1000 - 1200 RPMS until warm, then falls to 800 RPMS. I've changed the oil, spark plugs, both coils, wireset, coolant temp sensor. At first I thought it would of been my converters because they do get hot and start smoking a little but I disconnected the pipes and it still had those issues. I was told it would be either my TPS or MAF Sensor, but the MAF sensor is not cheap so I would like to make sure it is that, that is faulty before i make the investment. I have cleaned it already and its still doing the same thing.... I would appreciate i you guys would help me on this????

O. L. T.

iTrader: (17)

Freebie this time.

https://www.clublexus.com/forums/sc-...d-and-and.html

Moved to proper forum.

Bankswood

Can you pull some codes? I doubt it's a MAF issue. You can disconnect the MAF and if there is no change then it is the MAF. As for TPS you could borrow one or buy a new one and install it to see if it solves the problem. It is an easy replacement so you should be able to install it with out marking it up cosmetically. If that's not the problem just return it.

jadu

iTrader: (42)

there's a tutorial on lextreme on adjusting the TPS. See if that helps.

From personal experience, cleaning out my MAF was a big mistake. It would die, sputter, car smelt bad. Wound up buying a new one.

SnOwY22

Well the check engine light does not come on so I cant get any codes. But I am going to try disconnecting it to see if there is a difference or try adjusting the TPS and hopefully that works. Do you guys have an idea what else could be the cause of this??

SEXC

iTrader: (2)

Get yourself a service manual and a multimeter. These two items will help you a lot overtime. Also I doubt it's the TPS or MAF since the car runs fine after warming up. Good luck

Bankswood

Just because the CEL is not on doesn't mean you can"t pull codes. I've pulled codes twice and never had the CEL on.

cali108

iTrader: (1)

almost same issue here, 92 SC4

Unplugged my MAF and no difference at all!
Checked each coil and when unplugged each one separately, both sides stumbled and ran differently
Cleaned IAC

MAF?
TPS?
ECU?

here's a vid of the problem..

http://s31.photobucket.com/user/cali...ab636.mp4.html