The car turns over a while before finally firing / starting. It runs rough about 20 seconds, then it's smooth and runs fine. Doesn't matter if it's hot or cold. Only code I have is code P0442, which has been on for a while. I clear it and it reappears a few days later. It always starts, it just needs to do it quicker. What should I check?
P0442 is an evaporative system leak. I don't think that is going to be related to the poor running. You could have a dirty throttle body. Not a bad idea to look at your air filter element and see if it's very dirty. Your engine might be starving for air.
Another possibility that occurs to me is a fuel pump problem. Many fuel pumps have a check valve that keeps pressure in the fuel rail, and sometimes they bleed off the pressure after sitting. Try cycling your key on and waiting a few seconds before cranking over the engine - see if the starting is smoother.
The fuel pump check valve is probably not serviceable. You will likely need to replace the fuel pump assembly. If you have access to a fuel pressure gauge that would tell you for sure.
I'm not sure what the fuel pressure is supposed to be but my guess is something like 35 PSI. The real question is does it drop when the key is off.
×
Pull the vac hose off of the fuel pressure regulator and see if any fuel is in it. If so that is your problem
Testimonial: "It turned out to be a bad fuel pressure regulator. Replaced it and car starts and runs as it should. There was no gas present in the vacuum line when off, but there was gas while engine was running."
549 views
Usually answered in minutes!
Air filter looks fine. The throttle body had some carbon in it. I washed (w/o removing it) with good throttle body cleaner, a soft brush & spray. I also cleaned a sensor & it's port in the throttle body. Do I need to remove the throttle body & clean the underside? What's so weird is that it runs fine after 15-20 seconds of running.
Yes, I agree, it seems like the fuel pressure is bleeding down. Do you know if there's a check valve? Have tried the key / pump cycling, but it does not seem to help. (even though you would think it would).
I was hoping there might be a fuel check valve near the fuel rail, or does the regulator do that? I did just buy a fuel pressure gauge but don't see a test port. Also, I saw different specs for fuel pressure. Do you happen to know what the correct pressure should be?
I've seen 2 posted pressures in the high 40's and low 50's PSI range. Either way, it should hold pressure and not drop right down when the pump is off, right? I guess the fuel pressure regulator would not have any effect on this?
Gave it a tune up- plugs, wires, fuel & air filters, etc... No change, still turns over quite a while before starting. Where do I hook up a fuel pressure tester to check the supply & drop off?
You should be checking for codes a day or so after you get any dash light on. Been there awhile will cost you big time some day. You diagnose & repair all vehicle issue within a week or stop using it The PO442 as Steve siad is an EVAP System small leak. Could be a cap cap loose or other system solenoid,vent,pressure,canister,purge,etc. The Evap Monitor is the last one to run & it will every few days. With any vacuum leak in the system once your driving the purge valve opens & you remove the fuel tank fuels. Now the extra air fron your leaking solenoids or hoses add to unmetered air into the engine & it leans out the fuel trim the computer compensates & now your rich. Get it smoke tested & fixed
Gas Cap loose
When the purge valve opens you remove the fuel tank fumes,typing to fast today
I thought I answered this long ago. It did turn out to be a bad fuel pressure regulator... I replaced it and the car has been running fine... Thanks!
×