Car turns but doesnt run

We have a 97 Mercury Cougar XR7 4.6 v8, the engine will turn over and wont start, if you spray somthing into the throttle body than it will pop out the throttle body, could this be the timing chain? Is it possible for the chain to slip?

Reply to
Adam
Loading thread data ...

Possible but highly unlikely.... FWIW, this motor has two timing chains... the chance of both of them skipping time would be astronomical..... if either one of them comes out of time, it could be very spendy....

I can only suggest that you start with the basics... a code scan is the first order of the day to determine if there is a "hard" component failure or not. If all you see are symptomatic codes, progress onto fuel pressure - checking with a gauge is much more reliable than watching a spurt of gas stream out of the Schrader valve - I've seen many get fooled at this step. If we are getting 35ish PSI and we can bleed a sample off the gauge to look at it..... step the next (I had a 99 F150 late last week with a fuel pump that could pump and hold 35 PSI of AIR pressure!!!)...... just when you thought you'd seen and heard everything there is to see and hear.

If we're still looking good, we check for spark and fuel injector pulse.... doesn't matter which first. A noid light is the best bet for injector pulse, a powered test light is the next best choice and an incandescent test light can lie to you because the bulb often can't react quickly enough. Injectors are ground side switched... that is to say that they receive a constant B+ (that's battery voltage) with the key in run. The PCM switches the ground circuit open and closed. -

If we are testing spark, we are best using a tester like this

formatting link
. This style
formatting link
has lied to me in the past and I no longer use or recommend them. Since your car uses four coils in a wasted spark configuration, you will need to test for spark at every spark plug connection. Clean any debris from the area and inspect each spark plug well for moisure and crap at the same time. Thos would also be an idela time to inspect or replace the spark plugs..... if the fuel system is working but the ignition system isn't we might expect to see wet spark plugs.... if this is the case, suspect gasoline in the oil and possibly no compression due to the oil being washed out of the ring lands. If, for some unGodly reason, we haven't found the cause of our concern by this point, we can only assume one or more of the following.... we have plugged cats.... our gasoline isn't as good as we think.... we have a pooched motor..... or we haven't performed a test step properly using the appropriate tools.

And you thought I was just another pretty face...

Reply to
Jim Warman

FWIW, Jim... a question:

Doesnt this engine use the 'wasted spark' ignition?

And what are the chances of starter fluid igniting in the opened cylinder?

Just wondering... esp as this is the second post relating that symptom.

"Jim Warman" wrote:

Reply to
Backyard Mechanic

Do you hear the fuel pump as you turn key to on?

Should run for 2 seconds or so. Listen closely, while outside car, it's in fuel tank

Reply to
Backyard Mechanic

I did mention that this engine uses the wasted spark configuration... though I admit that I didn't explain the premise ( I would hope that someone with no knowledge of this would ask rather than nod their heads like a parcel-deck poodle). Since this system features paired cylinders, when one cylinder nears TDC and spark occurs, it's running mate is nearing TDC on exhaust so there shouldn't be any concerns unless a valve train problem is present. Keeping with our basic "simple stuff first" diagnostics, we are going to be sure that the most basic requirements are met first before we venture into more complex issues. Without spark and/or fuel.... there's no sense in checking other functions.

Whether or not there is backfiring in the intake, smart money is on avoiding shortcuts.... like going to the doctor - all you want is for him to stick his finger up your ass..... errrr, I meant all you wanted was a prostate exam, but they did the temperature, blood pressure, questionaire thing first.

Before we stick our finger up our motors ass, we need to make sure it's "breathing"....

Reply to
Jim Warman

Well, my point on that is that if it's 180 out, spraying starter into the intake, while the exhaust may still be gapped might cause a pop.

Plus 'lean' condition due to choke open when cold often caused carb back- popping as I recall.

Reply to
Backyard Mechanic

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.