I just got the truck this past weekend, and I was running through the gears (5 speed) to see the power of it. As I was in the 2nd (maybe 3rd - don't exactly remember) gear at around 45 mph or so (no tach so I don't know the RPMs), the truck hesitated alot, and it seemed to shut down. I pushed the clutch in and shifted gears, gave it some gas, and all it did was to sputter and it wouldn't go. Well, I pushed in the clutch fearing that I might have blown something, and coasted onto a side street. I tried to see if it would go again, so I released the clutch and it went without a problem. I made couple more "quick" runs down the street, and it was fine, no sputtering or hesitation. Now what could have caused this?

Here is a little history behind the truck. The guy I bought it from had it at his lake house sitting around for a year or so without driving. He got it out and it wouldn't run at all. He had to do a tune up, drain the old fuel, clean out the gas tanks, put new injectors it, new fuel filter, new spark plugs...etc. I think that there might heve been some old gas in the truck and it might have gotten to the engine. I put new fuel in it, and some Techron fuel additive. Maybe running a clean tank of fuel through it might help. We'll see if this happens again.

 

might wanna check the gas pressure..you could have a bad fuel pump...I just replaced 1 of mine because of a slight hesitaion and all is well now. Also change the fuel filter first..never know when that was changed.

 

Happened again last night. I noticed that this is happening as the fuel tank gets low. Maybe it could be fuel pump. I switched to rear tank and I'll see if the same happens as it gets down towards empty.

Oh yeah, I still havent had a chance to change the fuel filter. I will do that this week.

 

If it does it when they are low it could also be dirty tanks or bad gas....All the crap is at the bottum of the tanks, I was told by a machanic to never let the tanks get much less then a 1/4 of a tank because it's much harder on the fuel pumps and all the dirty stuff is at the bottom.

 

I've got a similar problem on an '89 F150. It's a 4.9L, Inline 6 cyl with EFI. I've got about 135,000 pretty easy miles on it with just regular maintenance and some typical replacement of engine components, but nothing major. For quite some time my truck acts very cold natured. It sputters, chugs, and stalls regardless of the temperature. It does it at the low ends of the RPM scale and seems to run normal with the higher RPMs. It does this regardless of the gear it is in (manual trans) and is aggravated when loaded (starting off or headed uphill). I've had it to a couple of reputable shops, but they can't pinpoint the problem. I changed the ignition coil this weekend after looking through the message boards. No success. I'm thinkiing the fuel pump is the culprit. Is there an easy way to check the output of the pump as mentioned above. I'm an amatuer willing to try almost anything......if that helps. Also, would the pump problem be the low pressure in the tank or the high pressure out of the tank on the rail. Any suggestions or help would be appreciated. Thanks in advance


Slug