bad problems starting..please help

[kycycles]

bad problems starting..please help(update)

alright guys and gals....i have a 99 explore 4.0L i have been running an engine code for over year now that points to map sensor and 02 sensor, but i have never really had any issues with the truck running. it has always gotten around 16 mpg and still does. however, here lately it is having a very hard time starting. it acts like its not getting fuel at start up. when it does start it runs very rough for about 20 seconds or so, then it runs fine.

could this have something to do with my current engine codes or might it be fuel injectors? can you test injectors?(i have not opened my manual yet) how much are they new from the auto parts store

any and all suggestions would be great. the truck has 175000 miles on it and is a good truck. i need to get my but in gear and make sure it stays that way

 

[FIND]

Most of the time, if it is a fuel injection problem, it would throw an additional code. As for your problem, more troubleshooting will be required. The first step would be to check fuel pressure at your fuel rail. You can also unplug your battery for 15 minutes to reset the ECU to factory settings to see if that makes your problem go away or diminish until you have gone through a few drive cycles. This will tell you if the problem is related to things the ECU has learned from having the faults, although, a faulty MAP sensor would usually cause the engine to go to limp mode, which wouldn't have the same type of hard start condition as yours does.

Before anything else though, it would be very helpful if you posted what codes your ECU is throwing. You can have codes read lots of places, like Autozone or the other such parts stores.

 

[kycycles]

ill run the codes tomorrow and then reset the computer..stay tuned

 

[kycycles]

ok...i reset the computer and i am waiting for the engine light to come back on. however, it is still having a hard time with cold starts. warm/hot starts are perfect.
when it does fire on cold starts, it feels like the motor is going to fall out.

 

[kycycles]

the engine light finally came back on. i dont have the codes in front of me but this is what i remember

171 /174 bank 1 and bank 2 (too lean i think)

and 301 ??( cyl 3 misfire detected) this code is new. the first two have been there for years.

i did run some lucas fuel injector cleaner through the gas. this actually makes my bad starts last longer....

i am going to replace the plugs again, but i did this a few months back..however...one of the new plugs cracked on me somehow and was causing cyl 4 to misfire. this particular misfire never went away like my misfire now. i quickly correct the problem with a new plug.

any thoughts on all this??

 

[kycycles]

i pulled and replaced number three plug. it looked fine and the new plug did not change a thing. This truck is to the point now, that it barely starts. it seems the fuel injector cleaner made it worse. i hate using additives and have no idea why i decided to use it this time...

 

[bobflood]

and 301 ??( cyl 3 misfire detected) this code is new. the first two have been there for years.

I thought P0301 was a cylinder 1 misfire?? I.E. P030X, where X is the cylinder with the issue.

 

[kycycles]

it was 303...i couldnt remember what the code was when i posted

anyway...i replaced the #3 plug and nothing changed. i replaced the number 4 plug and now i am running on all cylinders again.

This morning, the truck fired right up. this afternoon, it struggled somewhat but it started. it was a little rough for about 10 seconds but then ran smooth.

i would like to go ahead and address my p171 and p174 codes. how can i pin point the cause of these codes??

 

[kycycles]

ok all....still having rough starts but after 10 seconds or so it runs smooth as can be,. i currently do not have any codes since a reset the comp on the 12th.

find... i have not checked fuel pressure yet, but if it were low, wouldn't i have problems with gas mileage and driveability?

i have not been able to locate any vac leaks'

i tried to prime the pump a few times before i start it, but that does not seem to help

 

[JG88]

If it's running lean on both sides then my guess is that the fuel pump's going. They can do some strange things when they're on their way out.

I chased an intermittent 171/174 issue on my truck for 3 years. Everyone told me to change the pump, but I couldn't believe it was that since the truck ran so well other than throwing a code. It got to the point where it had hard starts/no starts, and gave out completely soon after. I finally changed the pump, and I haven't had a lean code in 2 years.

I would change the fuel filter first to make sure that's not causing it. It's a lot easier than the pump, and you'll want to change it if you do the pump anyway.

 

[kycycles]

i changed the filter a while back with no change. i will change it again if i do the fuel pump. it could probably use a fuel pump with this many miles anyway.....ill get around to that soon. ill be in touch. i have not looked it up yet, but is it a pain in the butt?

 

[windsors03cobra]

A fuel pressure test is in order for sure. See this kind of problem in many Chryslers where all the fuel bleeds off due to a bad in tank check valve.
Also fixed a problem like this on a GM car this weekend, had 5-12 pounds of fuel pressure, then none and wouldnt start.

Good luck

 

[corkey]

i had the exact same issue with my 99 ohv

it would throw random codes, like the 402 and 301, and sometimes other egr codes,
i trouble shooted it by unhooking the spark plug wires at the coil one at a time , till i found the one that did not affect the idle, it was #1 ,
i changed all the plugs and all the problems have mysteriously vanished, no more check engine of any kind,,

start there as it is the cheapest option for the start,

 

[kycycles]

ok...i am getting a fuel pressure reading of 60 psi with vacuum attached.. according to the book, i should be at 30-45 psi. i am going to replace the regulator today as i cannot really tell if i have a blockage in my fuel return. i will also check the vacuum pressure once i re-install the regulator( i jumped ahead of myself and pulled the reg off before checking the vac)

can a bad regulator cause my starting problems and my misfires?

 

[2000StreetRod]

fuel pressure is normal

The fuel pressure for a 1999 should be 60 to 65 psi for all engine conditions. The fuel pressure regulator is in the tank. The component on the fuel rail is a damper. The lower fuel pressure (30 to 45 psi) applies to the older return type fuel systems. Yours is a returnless. See Ford Explorer Ranger Fuel pressure test procedure

You never posted which engine you have. Is it the OHV or the SOHC V6?

 

[kycycles]

mine is the push rod type. the regulator with the return hose is mounted on the side of the rail. the haynes manual says max pressure of 65 but idle pressure 30-45

 

[kycycles]

ok i stand corrected i think. that is not return line, that is a feed line

 

[kycycles]

well i put everything back together after testing. it actually has fired right up several times, but i have a miss(presumably from what ever has been causing all my codes) i am going to replace the plugs again tomorrow and see what happens.

could the fuel pump still be causing me problems even though its tested good. and why in the crap does the haynes manual give different numbers. based on the manual, my pressure is too high and the cause would be vacuum or regulator(150 bucks or so)

that being said, i am getting 9psi vac into that damper?

 

[my98nnj]

Cold start issue might be as simple as the engine coolant temp sensor issue. Check it's value cold and compare it to the temp/resistance specs.

 

[kycycles]

cool temp sensor. thats a new issue, is there a link that addresses this?