Sputtering Acceleration & Erratic Idiling

[Explorer_Pat]

I have a '01 V-6 4x4 that I just had towed home. I was in heavy boulevard stop & go traffic when my truck felt like the engine was about to die. At each acceleration from traffic or a stop light I had to hit the gas pedal several times because the acceleration would die out and feel like it was about to stall on me. As I continued down the street it got worse and worse so I pulled into a parking lot.

With the truck idling I noticed it was jumping from 500 rpm to 1000 rpm still sounding like it wanted to die, but reving the engine like I was giving it gas. It was doing this steadily like once per second.

When I did give it gas it sputtered and when I floored the pedal there was a gargling sound almost like it wanted to backfire (can fuel injected vehicles backfire?). One last thing is when I went to the back of the truck the tailpipe was emitting a fast sputtering sound.

If anyone has any suggestions all are welcome.

 

[Explorer_Pat]

I took it to my mechanic and he thinks it might be the fuel pump or the catalytic converter. The probelm is that it has been running normal and I can't get it to exhibit the symptoms I stated in the original post. Should I just change the fuel pump anyways or wait until the truck acts up again?

 

[Vinniety]

I took it to my mechanic and he thinks it might be the fuel pump or the catalytic converter. The probelm is that it has been running normal and I can't get it to exhibit the symptoms I stated in the original post. Should I just change the fuel pump anyways or wait until the truck acts up again?

It sounds more of a miss then FUEL issue. How many miles do you have? When was the last time you gave it a tune up. How hot was it that day? The heat maybe caused something to go crazy. Give us more info so at least we can TRY to help.

there is an easy test for the catalytic converter. Get the truck running for about 15-30 minutes and look underneath at the cat. It is before your muffler on the same pipe and see if it is red. Like a glowing red. NO DO NOT TOUCH IT but just see if it is getting red. That can tell you or at least give you an idea if it is clogged.

 

[manaen]

CAT problems will not go away magically, if it is clogged it will be a constant thing.

There are a few things that can cause those issues, check your plugs and wires, check for vacume leaks, and check for fuel pressure.

Are there any codes being reported by the computer? If it has a misfire the computer should report the problem after a few run cycles. However if the problem is gone then it will not be reported.

 

[Explorer_Pat]

It sounds more of a miss then FUEL issue. How many miles do you have? When was the last time you gave it a tune up. How hot was it that day?

Mileage: 150k
TuneUp: 6 months ago
Temp : 111° It was the hottest day of the summer yet here in central California.

I changed the fuel pump anyways because I didn't know what else to do and I'm still running fine. I took a 400 mile trip over the weekend and had no problems with sputtering or overheating. I dunno, but today I'll have to get back in heavy stop and go traffic but the weather forecast is only for 99°

There are a few things that can cause those issues, check your plugs and wires, check for vacume leaks, and check for fuel pressure.....Are there any codes being reported by the computer?

There were no codes, but I was told fuel pressure was low which is why I changed the filter and pump. When I first took it to my mechanic he also said it could be an injection sensor (I think), too, if I remember correctly. Don't know how likely that would be.

 

[Vinniety]

Mileage: 150k
TuneUp: 6 months ago
Temp : 111° It was the hottest day of the summer yet here in central California.

I changed the fuel pump anyways because I didn't know what else to do and I'm still running fine. I took a 400 mile trip over the weekend and had no problems with sputtering or overheating. I dunno, but today I'll have to get back in heavy stop and go traffic but the weather forecast is only for 99°



There were no codes, but I was told fuel pressure was low which is why I changed the filter and pump. When I first took it to my mechanic he also said it could be an injection sensor (I think), too, if I remember correctly. Don't know how likely that would be.

Well you changed the pump and filter which is a good thing especially with that many miles. Maybe the Mass air flow sensor got really hot and started to make the truck run rich or lean. Anyway keep us posted but it sounded more of the heat causing an issue. Good luck

 

[Highroller]

My truck was doing the same thing constantly for 3 weeks and I fixed it with a new IAC.

 

[Vinniety]

My truck was doing the same thing constantly for 3 weeks and I fixed it with a new IAC.

Is that the same as the Mass air flow sensor? Sorry but forgot what IAC was.

Disregard: Idle Air Control.

 

[manaen]

did he recheck fuel pressure after the install? If I rememeber correctly, 2000 model year had the loopback fuel rail with a fuel pressure regulator, did he check/replace that as well? 150k is really not super high mileage for a fuel pump I have had numerous fords that went to 200k without ever changing the pump. IAC would be a good thing to check, but it should only effect the idle state even if it is stuck open the computer would compensate for the lean mixture when you hit the gas.

When you say it had a low fuel pressure what was the observed reading?

the heat could be a clue, when electronics start to go they usually fail when they warm up. As they warm up the connections separate from the board, anyone with the stock explorer radio that has the dim face issue has expirienced this. Anyway I've had coil packs that have worked fine when cold and once heated up begin to miss and fail.

Your low fuel pressure would give you a lean mixture, only in the worst cases would this cause a miss, in most cases the computer should be able to compensate. If the fuel pressure is back into spec then start with the electrical stuff , plugs and wires, while your plugs are out observer the insulators for running condition of the engine. If they are white, your running lean, if they are black your running rich. Should be a nice gray color with no to little soot. This is a good indicator, however there are many things that can cause this.
keep us posted on your progess and we can help walk you through the diagnosis.

 

[dkam]

Me too! http://www.explorerforum.com/forums/showthread.php?t=192667

 

[EfromDenver]

I have a 2000 Sport with 106K miles and just experienced this last friday. It was a hot day and I had been driving from meeting to meeting. I finally had to pull over because I had no acceleration and towed it to a mechanic. The mechanic checked the mass air flow sensor first, then tested the fuel pressure. Mass airflow sensor was clean and fuel pressure was perfect. He then checked the fuel filter and it was "very dirty." He replaced the filter and we will watch the pump for a week.

When the filter is clogged, the pump has to overcome this by increasing the fuel pressure at the filter. When you fix the filter issue the pump can go shortly after so it is important to watch out for this (wait a week). He also said he could hear/feel a misfire on acceleration and I could use a tune up...