I bought A 1998 FORD ESCORT FOR $500 IT HAD NO START I CHANGED THE CRANK SENSOR AND KNOW I HAVE FIRE. CAR NOW RUNS.I TEST DRIVE IT FOR ABOUT 5 10 MINUTES AND IT STALLS. IT ACTS LIKE IT WANTS TO START BUT DOES NOT. IT CRANKS OVER, I HAVE A GOOD SPARK AND FUEL TO THE FUEL RAIL AND TIMING BELT IS GOOD. IM THINKING IT MAY BE THE VARIABLE CAMSHAFT TIMING SOLENOID SENSOR THE (VCT) I READ THAT IF THIS PART FAILS THE CAR WILL HAVE POOR PERFORMANCE AND OR STALL. THAT PART REQUIRES ALOT OF WORK TO CHANGE. DO YOU THINK THIS IS MY PROBLEM?
I checked for vacuum leaks and this car does not have an ignition module and yes I checked the MAF. On distributerless ignitions the crank sensor reads off the crankshaft and sends a signal to the pcm, (computer), the pcm then sends a signal to the coil pack telling it to fire. On this model of car the 1998 ford escort zx2 2.0L dohc it has a variable camshaft timing solenoid (vct). This acts like an egr valve it helps performance and lowers combustion chambers temperatures and gas milage. If it fails in the fully advanced position it may stiil run, but if it fails in the fully retarded position it may not want to start or run at all. If you have spark, compression and fuel you have a running engine. What I think is happenning is that the vct which connects to the exhaust cam is retarding it so much that when the pistons is coming up for combustion the exhaust valves are slightly open causing you to loose compression.
March, 12, 2006 AT 10:17 AM
Yes, spark, fuel, and compression will give you a running engine, It is also required for all to occur at a certain time. I do believe that you would hear a backfire thru the exhaust system if the exhaust valves were not fully closed.
The test for the VCT seems pretty straight forward.
With the ignition off, unplug the wiring harness from the sensor.
Check the harness for continuity and shorts to ground. Repair as needed.
Reattach to the sensor.
Using a digital volt ohmmeter on the resistance setting, probe the terminals.
Resistance should be between 3.0 and 6.0 ohms. If not it is bad.
Not something I would want to change needlessly.
Will the engine restart?
How does it run until it stalls?
Are the plugs wet, black, or white and dry after it stalls?
Some other things to check.
A compression test.
Fuel pressure. Even low pressure will affect performance, starting, etc.
Leaky or clogged fuel injectors.
The O2, CTS, IAT, and TPS can have an effect on performance and starting. A good scanner will show performance related issues for these units vey quickly.
Some DIS systems do have ignition modules. Yours does not. My mistake. : Oops: Good hunting and let us know what you find. : )
March, 12, 2006 AT 2:36 PM
Yes the car does back fire through the exhaust and the plugs are slightly black. The back fire through the exhaust is another indication of the vct failer. The car acts like its going to start but does not and somtimes does but dies in like 4 seconds. As for fuel pump pressure I injected gas into the intake and it still would stall or not start at all. Like I said I have very good spark and fuel pressure but im loosing alittle compression I think due to the vct retartarding the exhaust came to much.I tested the resistance in the vct and it read good but that doesnt mean the mechanical part of the vct is good. After I installed the crank sensor the car ran with full power and very very good acceleration for about 5 min and then all power cut off. Then when trying to restart it acted like it wanted to start but just would not. It had back fire through the exhaust. My compression gauge broke so I cant test the compression right now but im sure it would be low. What are youe thoughts
March, 12, 2006 AT 5:59 PM
I just retested the (vct)variable cam timing solenoid set my digital meter to 20 ohms scale and I read 0.01 and that means its bad. Strange I tested it before and it read 3.0 ohms. Dont you love electronics.I need some special tools for this job. Camshaft alignment tool #t94p-6256-ch, timing peg tool for crank alignment #T97P-6000-A
March, 12, 2006 AT 7:07 PM
: D Go with the best 2 out of 3 readings.
March, 29, 2006 AT 11:42 PM
I FOUND THE PROBLEM. AITHUOGH THE VCT WAS BAD IT WASNT THE PROBLEM.I PULLED OUT THE CRANK SENSOR I INSTALLED EARLIER AND IT WAS RUBBING ON THE FLY WHEEL WHERE IT READS OFF OF.I HAVE CRANK WAIK OR BACKLASH ON THE CRANK. I DROPPED THE OIL PAN AND INSTALLED A NEW CRANK THRUST BEARING TO PREVENT THE CRANK FROM MOVING BACK AND FOURTH. REINSTALLED EVERYTHING AND TESTED. RUNS LIKE A CHAMP.
March, 30, 2006 AT 6:30 PM
Hey allright. : )
Thanxs for sharing your solution. Not a common one.