3.0 running rough . dieing out and sputtering

[1986fordranger]

howdy yall long time no see . anyway i'm looking at buying a 1998 ford ranger 3.0l v6 5 speed 4x4 with 185.000 miles . the engine is hard to start when cold and likes to die out and sputter . now heres my question . one of the past owners have cut the four wires on the plug for the mass air flow sensor and have been spliced back together . plus theres a jumper wire running from the + on the battery to the red wire running into the MAF sensor . without that jumper wire connected the truck won't fire . note there is no check engine lights on in the dash . the only thing i can think of that might be the issue is that part of the ECM or engine control computer is fryed leading to the engine not fireing without 12 volts direct to the MAF . anyway any suggestions would be great . thanks

 

[shane96ranger]

Here's the pinout you should have on the MAF below. Also, have you checked your fuel pressure?

EDIT: This one is probably more helpful for you......

 

[1986fordranger]

thanks very much for the pinout diagram . next time i go look at the truck i'll check thoses circuits and see what i come up with . the strange thing is the engine runs abit smoother if i unplug the MAF connector when running . although i guess that could be a coincidence . i'll also check the fuel pressure . thanks

 

[shane96ranger]

There is always the possibility that the MAF sensor itself is dirty. I've had it throw a code on me (wife's Cougar with a 4.6), and I've had it not throw a code (my Ranger with a 4.0) when I've had issues.

I've gotten to the point that it's just part of my yearly maintenance to clean the MAF sensor.

 

[Rearanger]

one of the past owners have cut the four wires on the plug for the mass air flow sensor and have been spliced back together . plus theres a jumper wire running from the + on the battery to the red wire running into the MAF sensor .

Are the wires spliced together or spliced into the MAF plug? Did previous owner try to fool the computer into thinking MAF was hooked up?

 

[1986fordranger]

Are the wires spliced together or spliced into the MAF plug? Did previous owner try to fool the computer into thinking MAF was hooked up?

the wires where cut right by the MAF connector and spliced back to the correct wire colors . the only reason i can think of for the cut and splice job would be if the past owner wanted to replace the MAF sensor and didn't have the correct tool to undo the screws that hold the MAF to the houseing . but then it'd be as simple as unplug the plug . so i don't really understand that . thanks

 

[1986fordranger]

i suppose some of the spliced connections might be corroded under the electrical tape and not getting power to the MAF .i'll have to check that out too

 

[Rearanger]

The spliced jump wire from the battery could be because of bad connection or break in 12v pwr from ECU.

Did you perform tests in post from shane96ranger? MAF does use air temp to send signal to ECU.

Other possible is engine coolant temp sensor, that would also explain bad cold running but good hot running. You can test ECT with OHM meter.