SHO not running well when cold

[nc89sho]

ok, first off, let me say that i do have a bad clutch (soon to be fixed) but when my car is cold sometimes (and sometimes when it's warm, but not often. it idles very poorly (New plugs and wires less than 20K old and motorcraft) if just seems to vibrate alot and when i'm giving it more gas while driveing, i get to a certain point and it quites pulling for a second, like it has to catch up to me. after it warms up or has been driven for a while, it's ok. and if i run it really hard for a few min (7K rpm trips) it runns and idles great for a few min. then goes back to being "slightly off"my dad's sho (aso an 89) did something similar and it ended up being the MAP sensor. before i replace that, does anyone else have any ideas?
by the way, no Check engine light or codes.
and my coolant temp sensor (both of them) are brand new

<small>[ March 05, 2003, 06:28 PM: Message edited by: nc89sho ]</small>

 

[SHO--ripper]

My 89 idles poorly, but no problems with power. Sorry but no ideas

 

[SHOman24v]

maybe you need to clean out your idle air control motor.....did you try that

 

[sdpatt]

The IAC won't cause a stumble or misfire, just a high, low or varying idle speed. If there are no codes, and you are having a spark misfire, you really need to check the plugs and wires. What gap were the plugs set to? Since the problem is more noticeable at the richer mixtures of the cold engine conditions, that would also point to a weak spark condition. You did say that both the plugs and wires were the Motorcraft AGSP32PP and WR-4033, respectively, right?

 

[haydenm315]

My idle has been funky while in the cold ever since I did the 60k, pullies, and race camshafts. The cams messed with the idle some and made it somewhat lopey. I cleaned the IAC/IAB thingamabob before doing the 60k and other stuff. Upon first startup on a totally cold motor in a fairly cold environment (10-35 degrees), my motor will start idleing around 1500rpm and slowly work its way down. The idle tends to jump around for a little while before normalizing. It does settle down after a little bit of warmup.

 

[AutoSHO]

I suggest to everyone with any kinda of Idle/Driveability problem to Clean your MAF sensor. The engine computer is completely dependant upon it to provide the airflow, which it bases all its calculations from. It only takes a few minutes, and the results are dramatic.

 

[FOSHO94]

I think that I need to do this, where exactly is the sensor itself? And, how would you suggest cleaning it?

 

[AutoSHO]

FOSHO94:
I think that I need to do this, where exactly is the sensor itself? And, how would you suggest cleaning it?

The Mass Air Flow sensor is located on top of the air filter box. It is a cylindrical aluminum casting with a black plastic electronics package mounted to the top. remove your airbox lid from the car, and then the Mass Air Unit from the lid. Looking into it, it will have a screen, and 2 holes, a small and large one. removing the screen is the easiest way to clean it. Once you have removed the screen, look into the small hole on the MAF body. There will be 2 wire filaments hanging down. These are what you want to clean. Use an electrical contact cleaner to spray the filaments down. This will remove any built up oils or dirt on the sensor elements. Once you have done this, put it all back together.


Alternately, you can buy the Tamper proof torx bit to remove the black electronics package from the top of the MAF body, and leave everything else in the car. This makes a more thorough cleaning possible.

 

[FOSHO94]

Thanks, I'll look in into doing that.

 

[nc89sho]

well i just had a wheele bearing go nuclear on me at 60mph on the highway so that explains alittle of the holding back the car has been doing, but i'm proud to say i am now the owner of a 90/89 hybrid hub assembly. i like the 90's bearings and shaft alot better that the 89. but back to the original post, i've cleaned the IAC and have reset the idle programming .. that helped, but it still seems alittle odd. wires and plugs are all good and motorcraft. i do apear to be running lean though because all 6 plugs were white as all get out. and powdery. also. if i hold the gas at just above idle (1000 rpms) for a sec or two the car will idle back down to 900 pm it's own and then when i take my foot off the gas the idle dropps to about 700 for a couple of sec. untill it works itsself back up to 900. is that normal?