What is common is after warm up.
Not one of you, has report ECT (engine coolant temp) nor fuel trims. These can yield valuable clues.
Also be mindful different years, have different known issues.
98-99 had T-body issues.
05-06 had hot soak issue. TSB out on that.
03-07 tend to have more EVAP issues. With their charcoal canister being in the rear. But all years can have EVAP issue. They tend to manifest after warm up..
I am still having a long start issue and have narrowed down to the following:
If it sits for 24 hours or longer it starts right up. Honestly if it sits for a couple days it starts the best.
After running at operating temp and I shut down and start back up within 1 min - 15 min. it starts right up. But, if I let it sit for an hour or two up to 8 hours it has a long start. (Turns over strong for a couple seconds before catching and sometimes stall and have to restart). Otherwise once started no issues at all.
To recap the following has already been replaced in the past 6 months:
- Fuel Pump
- Fuel Filter
- Fuel Regulator
- Spark Plugs
- Battery
- Main Fuse / Relay box and new EFI relay
- Air Filter
- Mass Air Flow Sensor
- Throttle Position Sensor (cleaned throttle body when I replaced this)
Opinion on could it be the fuel injectors, crank position sensor or what should I try next?
Year and miles, is best put into signature line. Different years, different common issues.
Going to bump this thread because I found out last weekend I have almost the exact same thing. If you get gas or something (aka a short stop) it still cranks up fine. But if you stop a little longer than that, and then crank it will have a long crank before catching. And yes, cold starts are totally fine.
I had this on a totally different car one time and it was fuel pump. But it sounds like that is not the case here.
I'd inspect engine visual, listen to engine sounds and get some data points.
Looking for:
Loose vacuum hoses.
Hoses connected wrong.
Loose, damages or improper routing of wires.
Loose parts.
Check fluids level and condition.
Then test drive and log data:
Fuel trims, ECT, A/T temp, IAT, CAT temps, MPH, RPM, etc.
Very often I'll find ECT (engine coolant temp) to high. The water temp gauge on dash, is misleading.
Second are fuel trim in or out of range.
On test drive, as I get onto HWY. I floor it, hold pedal to the floor. Feeling for a nice smooth acceleration or is there hesitation or misses.
Smells.
Are there unusual odors. Like heavy fuel smells (fuel mixture or spark issues) or old stale fuel (EVAP issue, like fouled CC).
Sound:
Ticks, knocks, squeals, etc.
Scan for codes:
Pending or current.
Service history:
Any work just done or done shortly before issue began. Many issue, are created during service.
What parts used. Junk coils, tend to be more susceptible to heat.
Depending on what I find. I then get idea of where to target diagnostic work first.
I have this same issue, after doing a starter/valve cover replacement. Not sure if that's coincidental, but I don't know what I could have done to cause it. I figure if there's a fuel leak it would smell. Some googling says it could be leaking fuel through an injector into the piston, but if that were the case, wouldn't there be noticeable fuel smoke/rich smell from the exhaust on startup?
As I said in other thread, you've asked this. Likely you cause issue!
90% chance something you did or didn't do correct, caused the issue. 8% chance you did not, notice before service. 2% chance, it just happen after you fished the starter job. I start with, checking for vacuum leaks.
If you posted detail picture before, during and after. Or even give detail of every step of starter & VC service. Perhaps we'd spot something easy to correct.
I think this has something to do with the fuel damper. The little metal can thing on the driver's fuel rail with a screw sticking out of it.
I replaced mine with new and I've been turning mine 1/8 turn at a time in for the last few weeks trying to get my short stop restart dialed in.
It shouldn't be screwed in all the way nor should it be out. It needs to be screwed in partially, but not too much, just the right amount.
Is this the same 07. You bypassed the fuel pump resistor, to run it full speed at all RPM?
Have to tried turning all the way in, then all the way out,. Just to see if any difference in engine idle, RPM, start, etc.?
I too, played with fuel pulsation damper screw, many years ago. IIRC, it's non adjustable.
There is one test in FSM. It either pops up, when fuel pump running (good), or it does not (bad).