Had a Problem with my Truck Today

[Hzd Skizzy 27]

I stopped at the store today and parked it and then came back and started it up, sounded fine, then put it into reverse and apply the gas a little. It acted as though it was stuttering. So I put it in drive and same thing, it stutters no matter how much I push the petal, it will not go above 5 mph or above about 1.5k rpm. As I got on the road I had to pull it over and troubleshoot because It was just to slow. If I had to describe what it felt like...It was the feeling of putting a manual car into 5th gear and trying to make it go from a stand still. Acts as though it's about to stall out but it never did. So first, I put it into park, turned off the truck, turned it back on and rev'd it, now it was fine. But as I got home I decided to check a few things out. First thing I noticed was it was idle-ling at 500 rpm. Knowing a little about electrical, it seems a tad low. I know my truck usually idles around 800-900 rpm. When I revved it to 900 it then went to 600, then i heard a click and lights would dim, then go 500 then up to 600 then heard the click, lights dim back to 500. Yes, I turned AC on and off and other electronics to see if i could get it to possibly move but it stayed at 500 and it still does. I could not reproduce the problem I had earlier though.

What I have come to figure is I do not think it was a transmission problem because it didn't act as if it were slipping, like revving and then going to gear but it was not doing that, the feeling was consistent no matter what position the gas pedal was in. I'm guessing it's the fuel pump, or maybe IAC? But then again I am not sure. Monday I am taking it to the shop to talk about getting this looked at, but I just want to know what the case may be, so I could explain it a little better. Thank you very much for the help.

[shizzzon 461]

So, it's not doing it now?

Seems to me like electrical issue if it randomly just fixed itself..

Remember everything you have ever done to your vehicle electrical-wise and go back and check all ground and power connections.

Also.. if you are using standard battery terminals, unhook them both, apply a light brushing to the terminals(not harsh) all the way around including the terminals that the wire goes into and then reconnect them.

[StreetLegal 119]

you may want to check simple things also like air and gas filter

[nicholasrhall 0]

It seems as if your MAF sensor had malfunctioned but this would have thrown a engine light(most of the time it does anyway). What model vehicle would help, along with what engine. Also it could be IAC like you said, but im leaning more towards the MAF sensor because my scion did the same when it malfunctioned on me. Would idle really low and getting going was a bitch.

It doesnt seem like any electrical problem would cause this because if your car is EFI then idle control is mostly ran by on board computers and sensors. So my best guess would be that your MAF malfunctioned.

Also after all of that i would inspect all of your spark plugs. When it did it to mine it fried all my spark plugs(because i had to drive it 30 mins to get home.)

check to make sure all intake hoses are clamped into place properly and that your MAF sensor is plugged in all the way.

but thats best case scenario for that prob, worst that could be prob is your fuel pump took a shit on you.

Edited January 22, 2012 by NickHall

[Hzd Skizzy 27]

So, it's not doing it now?

Seems to me like electrical issue if it randomly just fixed itself..

Remember everything you have ever done to your vehicle electrical-wise and go back and check all ground and power connections.

Also.. if you are using standard battery terminals, unhook them both, apply a light brushing to the terminals(not harsh) all the way around including the terminals that the wire goes into and then reconnect them.

I did run 3 wires, 2 positive 1 negative, but they are dead. I put fuse blocks on them but they are unfused. Otherwise, no other electrical stuff has taken place. I brush the terminals though.

you may want to check simple things also like air and gas filter

I'm hoping that will be the problem.

It seems as if your MAF sensor had malfunctioned but this would have thrown a engine light(most of the time it does anyway). What model vehicle would help, along with what engine. Also it could be IAC like you said, but im leaning more towards the MAF sensor because my scion did the same when it malfunctioned on me. Would idle really low and getting going was a bitch.

It doesnt seem like any electrical problem would cause this because if your car is EFI then idle control is mostly ran by on board computers and sensors. So my best guess would be that your MAF malfunctioned.

Also after all of that i would inspect all of your spark plugs. When it did it to mine it fried all my spark plugs(because i had to drive it 30 mins to get home.)

check to make sure all intake hoses are clamped into place properly and that your MAF sensor is plugged in all the way.

but thats best case scenario for that prob, worst that could be prob is your fuel pump took a shit on you.

2001 Ford Explorer Sport Trac. 4.0 V6. Thanks for the help

[Hzd Skizzy 27]

Update: I went out with my dmm, placed it on the battery, rests at 12.7, always has. Turned on truck, started at 13.9, which it always has been at. Then 13.8, 13.7, 13.6 then when I was going to turn it off it was throbbing at 13.5-13.6. The time interval in which it changed by .1v was about 3-4 minutes. It was running for about 15 minutes.

[XxedgarxX 2]

you should check for water on you spark plug wires. maybe gas pump is has a loose ground ?

[Vitacy 2]

Does you're low traction light come on at all when this happens? Like while you're turning. If so it could be a stripped wheel baring harness. I have a stripped harness and what you said sounds almost identical I just let off the gas while going and slightly press on it an I dot have a problem afterwards.

[rps13joe 1]

I'd have to say its the fuel pump. IDK how many ford rangers I've done that had the 4.0L engine which is the same engine in the Explorers but they are notorious for fuel pump problems, I've done IIRC at least 6-8 ranger fuel pumps and 2 explorers fuel pumps. As far as your voltage dropping its also can be related to your fuel pump again, being most cars have a set minimum idle of 750rom +/- 50 rpm from what I know as your engine starves for fuel your engine will of course lose rpm which in turn slows down your alternator and causes a loss of charging system output. But thats just my 2cents. hope you fix it.

[jcardin 2]

On my wife's 2001 (job2) we've replaced the "elbow" that is on the front of the PVC tube that is a known and very common issue. http://www.mysporttrac.com/shared/msgboard9e.asp?BOARDNAME=MSG&VIEW=1167893&REPLYCOUNT=3&sitename=mysporttrac

We also replaced (separately) the DPFE sensor. This is another common problem.

Edited January 27, 2012 by jcardin

[Sir-Lancelot 216]

Fuel pump would be my guess too rps13joe.

[rps13joe 1]

2 days ago I replace the PCV elbow on a 4.6L 05 ford expedition, as Jcardin mentioned that too is a notorious know problem on a lot of ford trucks as well as the DPFE sensors but those 2 items from my experience doesnt cause a vehicle not to rev over 1500. the PCV issue can cause stalling issues due to the unmetered air and the DPFE is for the EGR which causes mainly rough idle due to it activating the EGR at idle when the EGR is meant for highway crusing. Both of those 2 common issue pretty much give you a rough idle but cleans up at higer RPM's so its highly unlikely since those 2 would illuminate you check engine light and a fuel pump doesnt.