Hey everyone,

New here and thought I'd try out a question with a problem I'm having.

I've got an F150, '89, 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. Any suggestions or help would be appreciated. Thanks in advance


Slug

 

Did you do all the simple stuff I assume? change distributor rotor, cap, wires and plugs? fuel and air filter? I'd then check fuel rail pressure. Should be 45-60psi at all rpm ranges. Clean injectors? Maybe a plugged cataletic convertor? I am assuming you've had the codes checked and nothing came up.

Anybody else got an idea?c

 

Do you have dual tanks and is it different or the same when on one or the other...if so fuel pump possibly.

 

Yep, I've done all the simple stuff myself or had it done, from plugs and wires to filters to injectors. To get in TN emissions I had all the O2 sensors and Catalytic Converter replaced. I do have two tanks and it does it regardless of position. I'll check to see if one is worse than the other. It does seem to be aggravated with low fuel in the tank. Could this indicate a bad pump? Your help is greatly appreciated.


Slug

 

Water or dirt in the tank???????