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 Michael Your Own Question
Michael
Michael, Auto Service Technician
Category: Car
Satisfied Customers: 919
Experience:  21yrs.Foreign and domestic driveability diagnosis and repair/ ASE Cert./Fuel Injection Specialist.
311867
Type Your Car Question Here...
Michael is online now
A new question is answered every 9 seconds

I have a 95 mercury villager that wont start. We ...

Resolved Question:

I have a 95 mercury villager that won't start. We were warming up the van in the morning and suddenly it began to surge and then stalled out. I have spark and I have fuel and the vacuum lines appear OK. The cap and rotor are both in good condition. There is a line coming from the transmission that looks like it's supposed to plug in somewhere, but I can't find a spot for it. It may be a vent, but I also can't find metion of it in my book, but it's in a few pictures. Any thoughts?

Optional Information:
1995 Mercury villager 3.0l

Already Tried:
check for good ignition spark, check fuel and changed fuel filter, inspected vacuum lines.





Submitted: 11 years ago.
Category: Car
Expert:  Michael replied 11 years ago.

You will need to check the actual fuel pressure and injector pulse and you say you checked for spark but don't say you have good spark.here is how to proceed systematically for a no start on a fuel injected engine.


Here are the procedures to check for a no start on a fuel injected engine.It will require a couple diagnostic tools that you do nt most likely posess,but may be able to obtain through a tool loan or rental program at many parts stores.


In order for an engine to run it needs the following:


1. Fuel (Fuel pressure gauge)
2. Spark (In line Spark tester)
3. Injector pulse (Noid Lights)
4. Air/Compression


You must determine which one or more is missing to proceed.


You can reduce the troubleshooting by spraying carb clean or a little ether into the intake throttle body to see if it attempts to start.If it does, then there is a problem with fuel delivery and not ignition.This will tell you whether or not there is fuel being delivered and isolate the issue to fuel pressure/delivery or injector control circuits.


FUEL SYSTEM PRESSURE 40-43 PSI(POUNDS PER SQUARE INCH)

VENT THE FUEL TANK VAPORS BY LOOSENING THE FUEL CAP   
THEN DISCONNECT THE ELECTRIC FUEL PUMP RELAY
PLUG, AND START THE ENGINE . ALLOW THE ENGINE TO RUN
UNTIL IT RUNS OUT OF FUEL AND STALLS.
AFTER SPINNING THE ENGINE OVER FOR A PERIOD OF (3) TO
(5) SECONDS, TURN OFF THE IGNITION SWITCH AND
RECONNECT THE ELECTRIC FUEL PUMP RELAY . INSTALL A
FUEL PRESSURE GAUGE IN THE FUEL RAIL SUPPLY LINE, AND
SECURE THE FUEL TANK CAP.
WITH THE IGNITION KEY IN THE ON POSITION, VERIFY THAT
NO LEAKS ARE PRESENT AND ENERGIZE THE FUEL PUMP.
THIS WILL BRING THE SYSTEM TO A STABILIZED FUEL
PRESSURE THAT CAN BE VISUALLY VERIFIED ON THE GAUGE.

You can check for spark at a spark plug wire while cranking with a flat tip driver or in line spark tester inserted into the plug wire boot and placed close to any metal part on the engine besides the fuel system lines and fittings or just plugged back onto the spark plug if using an inline tester.



To check injector pulse you will need a noid light set which can be purchased at your local parts store or through tool rental or loan programs as mentioned above.(Picture below)


To check for air just make sure the air filter is not totally restricted.


If all of the above are OK check compression at each cylinder with a compression gauge.The timing belt may have broken or jumped.


If this is OK you will need to check the fuel for contamination.(water etc.)


Please post back with your results so that we may help you through you car trouble.



Plug noid light into injector harness plug then crank engine.Light should flash.






















Michael and 4 other Car Specialists are ready to help you
Customer: replied 11 years ago.
Reply to Michael's Post: I have good spark and I have good fuel pressure. I have been able to start the car for just a couple of seconds and it revs up, it just won't stay running. I extracted the engine codes, and it says the knock sensor is not functioning properly. Would a bad knock sensor keep my engine from running?
Expert:  Michael replied 11 years ago.
No,not really.What was the fuel pressure reading at stall?