i have a 2002 mazda tribute/ford escape v6 that i am stumped on. first thing in the morning it will start and run with rpms jumping for a about 10 seconds and then die. during those 10 seconds if in try to give it throttle it instantly dies. after it dies it will not start again. i have confirmed spark at all plugs, i have confirmed all injectors are firing, short term fuel trims are pegged at 99%. starting fluid does not help. fuel pressure at the rail is 55+psi. i got it as a mechanic special so i have no record of what may have caused this. any idea of what may be wrong? thanks!

2002 mazda tribute/ford escape v6 with 125k miles

 

OK button not clickable because Vehicle Model and Engine not selected. Check my signature below to see why.
If you have a Mazda, say so, a Ford doesn't matter and just be specific. Both don't share the exact same engine components, wire colors as well may vary.

1) So have you checked for any DTCs yet? What do you have.
2) You bought the car and the very next morning you have the issue since then?
3) When the engine die like that you first check AIR, not fuel / spark. Unplug your MAF and restart, regardless of the rough idle, does it stall again or not.
4) If you want to check live data you check LTFT, not STFT. A 99% really interpret as N/A.
A major vacuum leak will have high positive LTFT (above +20), but a high positive LTFT doesn't mean it's caused by vacuum leaks alone but that's something to look into.

What is will not start again? No crank no start or crank no start?
How do you know your battery has sufficient power to restart multiple times?

No more guessing, provide your vehicle info then I can provide the pinpoint tests then we start from there.

 

Hi thank you for the reply. It is a 2002 Mazda tribute es with the v6. Unplugging maf doesn’t change anything. Absolutely zero codes or dtc’s. It cranks and doesn’t start after the first start and around 10 seconds of crazy idle and then dying. I bought the car as it is I had to trailer it home. Ltft is at 0% I’m not sure it runs long enough to go through that readiness test. Battery voltage is good I either have it connected to a jump pack or to another with jumpers to get a reliable crank.

 

 

Sometimes the simple things evade us.

You didn't mention the fuel filter. When was that last changed ?

Try to trace all vacuum lines coming off the intake manifold, a BIG vacuum leak is a possibility.

Look for a hose that came off or cracked and could be permitting that big vacuum leak.

Remove the check valve at the brake booster and make sure it is not stuck open.

 

Chart 7 shown below:








Chart 4 above.
Chart 5 below:



Chart 6 below:




Let me know if you need more charts.
Also download the intake manifold pdf below so you can identify and locate the relevant components when checking for vacuum leaks.

 

Something to keep in mind.

A fuel pump can provide low volume and build to correct pressure which will not show up UNLESS you watch how long it takes to build up that pressure.

Insufficient volume might be something to check with this problem.There are specs for amounts per minute , maybe Heiko can provide those specs.

 

Hi, thank you all for the replies and information. as far as vacuum leaks i replaced all the brittle hoses with new ones and the intake orings seem to be in good shape so i dont believe there is any vacuum leaks. one thing that concerns me is that starting fluid does not help it run which makes me think it is not getting good spark but ive checked spark on all cylinders and though i did get spark it wasnt very strong looking. more orange and faint instead of blue. changed coils and plugs with no change. checked/cleaned all ground points i could find with no change in spark. maybe im overthinking the spark think i dont know. ill post some videos of the plugs sparking. as of now i dont think it is a "underfueling" issue its more like its getting to much fuel and flooding. plugs dont seem wet after cranking though. im lost

 

All injectors and plugs react like this

 

Chart 7, 21 steps must go thru all that first.