Most of the time this happens, but not all the time...probably 90 percent of the time. I'll start the car the CEL will come on and it'll idle pretty rough, it'll bounce between about 600 to anywhere up to a 1000 RPMs, and than it'll dip down like it's about to stall and come back up, and the CEL will go off and on. Than it'll smooth out and idle real high, about 1100-1300 RPMs. And than when i drive it the speedometer doesn't work, but it runs like a champ. Also i get more exhaust fumes, smells sorta like gas. I pulled the codes, and got a code 33, which is high/low voltage at the MAP sensor, so i replaced the MAP and nothing, checked to make sure the hose and wires were connected. I don't know what it could be, could there be a hole in the hose or a short in the wires maybe? It's really annoying having my car sound like it has a huge *** supercharger on it and not knowing how fast I'm going. Thanks in advance for the input.

 

maybe the IAC. make sure its adjusted properly as far as the idle. i would check for a short and that the grounds are all good on the car. the speedo is another issue. is it an electric speedo? could be the sender is bad on the rear of the trans or the speedo sender gear is worn inside the trans. is your car a MAF powered car, i threw the same code once but mine was a maf car and it was my maf that was bad. wats the fuel pressure at? any mods to the car?

 

The thing is the speedo doesn't work only some of the time, always at the same time the car is acting up. No it's not MAF, its a speed-density motor, I'll try mucking with the IAC today, but i really think the speedo problem is related to the idle problem for some reason because they both happen at the same time.

 

hmmm not sure. maybe an electrical problem. still tho there is an electric speedo at the rear of the trans, follow the wires to the plug and the wires to the from of the trans. see if there are any shorts or soemthing maybe... its in the ECM sicne the speedo goes to the ECM and the idle is also controlled there. might have a falty ECM. any codes?

 

Only code 33, high/low voltage at the MAP sensor...