ive been reading around but no post would ever tell me what i need to know.

when my car is cold (sitting over night) and i go to leave the car will start fine but when i go to hit the gas it stumbles in low rpms so i give it some gas and it will drive fine it will do this untill the car is warmed up then theres no problems at all . the only code i get is VSS sensor , just a few min. ago i tried unpluging the MAF sensor and my throttle response seems to get so much better . so is my VSS or MAF sensor causing this? is it bad to leave the MAF unpluged?

 

bump

 

well i unpluged the maf and the car ran like crap so i dont know what the problem is . after it stumbles few more times i figured out the only time it does it is after i back out of the driveway then put it in to drive press the gas and it stumbles and almost dies so i give it a fair amount of gas then it takes off then no problems for the rest of the day. my driveway is pretty steep and when i back up i just roll down it to the bottom where its flat then take off . could it be trying to flood it self? its fuel inj. so that cant be it. im all out of ideas at this point.

 

Clean the MAF with electrical cleaner before u try anything else...
(ONLY electrical cleaner)

after that change fuel filter, could be blocked if it's old...

always try cheapest stuff first...

 

So I'm having this exact same problem with my car. When it's cold, the car runs horrid, and throws a code 33. As soon as it warms up, the SES light shuts off and the car runs beautifully.

The problem here is that I'm running a MicroTec 491018, which is equivalent to the Wells SU-145 that was popular when it had the plate-style sensor. It's not very old (<6 Months) so I don't think it's broken. I did have to cut and replace the wires that went to the MAF, but I soldered with high quality silver solder, heatshrunk the solder joints. Did a wonderful job, so I'm 99% sure that's not the issue.

Anyone have any clues why my MAF doesn't work when it's cold?

 

Could be trying to die b/c of not enough fuel. The fuel pump could also cause it to do that and map sensor needs to stay plugged in or the car will really run like ****. also it could be the map sensor could be bad but i would check on the fuel pump. Now one step to find out if the fuel pump is bad is to turn the key over not turn it on and hear if it huummssss. if its a continuous humm it should be fine but if it humms and sound like its weak or does a bubble sound its a bad fuel pump i knwo from experience since i had like 3 go out in 3 different vehicles and it was the same sound VERY sick soun you will tell. It should hum strong and for a few seconds so listen carefully.