Wont accelerate properly

[rio678]

Hi everyone

1990 Merc 190, with fuel injection by the looks of it, starts up fine, and revs ok, but when setting off, it wont accelerate properly, i have to keep blipping the throttle to get it up to speed, and 20 MPH is usually the most out of it?

 

[jberks]

I've had an escort and an Audi A3 do this. I both cases there was a leak after the Air mass sensor and before the air intake, allowing air to be sucked in after the sensor so the ecu thinks there is no air and as a consequence, puts no fuel in. Idling was fine as was start up, but you couldn't get it to actually move.
I've also has a Ford behave this way with a faulty knock sensor. It detected pinking and leaned the mixture to the extent that it was running on pretty much pure air.

I'd check the condition of the air intake pipes first.