need help diagnosing weird engine surge
 

I'm experiencing weird engine surge when i turn on my vehicle. I took it in for service, they said it was the master air flow. This didn't fix the problem :( Does anyone know what the problem might be ?

hc,

Will help to know model, year, miles, and your detailed description of the symptoms, nand if check engine light is on. And was this a dealer or an indy shop?

I'm sorry, the year of the vehicle is a 2006 range rover sport. I'm at 103889 miles. when I try to turn the car on, it takes a while to turn over and the engine light comes on. once its on the car starts surging. yes, to indy shop. He said the only thing coming up was the mass air flow. I replaced it today, but i'm still experiencing the same problem.

any help is appreciated :)

We don't have an 06 manual on the site, but here are some general ideas.


1. If you turn key and cranking is very slow, could be battery. If you turn key and have to hold or wiggle it to make truck begin to start could be ignition switch.

2. If truck surges, could be idle air control valve, which regulates engine at that idle speed. These can usually be cleaned with a solvent made for the purpose. If you can get the code number that would help.

Thank you so much. I'll check the code in the morning and post it.
i replaced the battery so thats out.

Was the MAF replaced with an OEM or aftermarket unit? The aftermarket units usually will not work. Try disconnecting your MAF, the computer will use default settings in the absence of the MAF sensor. If that takes care of the surging issue, then you have found your culprit.

try cleaning the throttle body. those tb was known to cause issues when gummed up. At the same time I believe you might be due for a rpgm of the tcm and the ecu. Had some issues on them years ago on SC but it might not be a bad idea if it hasn't been repgmed in a few years.