How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask justingsmith Your Own Question
justingsmith
justingsmith, UK Car Answer Team
Category: UK Car
Satisfied Customers: 18
Experience:  UK Car Expert
6179551
Type Your UK Car Question Here...
justingsmith is online now
A new question is answered every 9 seconds

MAP sensor..disconnected..the engine chokes, runs rough and rich

Resolved Question:

When I connect the MAP sensor vacuum line to the inlet manifold the engine wont start. When disconnected it will start and run but not that well. When reconnected whilst running the engine chokes, runs rough and rich. Whats the next step to sort this problem out?
Submitted: 8 years ago.
Category: UK Car
Expert:  justingsmith replied 8 years ago.
I had this happen some time ago, the engine would not start with the map connected?Very strange, but it did happen. Most people would think the crank angle sensor first but this was not the case.The MAP is a master in fuel delivery, if it is off, the entire fuel system is out of wack. most people are just not aware of how important the thing is. If the car runs better with it disconnected the ecm is dumping fuel. and nothing has more impact on fuel dilevery than the MAP in this stage( some meats might say the 02 sensor, or coolant sensor but not on old school fords)and defiantly not on start up! I would just replace the MAP, but there are simple tests you can do. First is make shure the old MAP holds vacuum. Hit me back if you need a full test.
justingsmith and 2 other UK Car Specialists are ready to help you