hi guys, Angie here(or what's left of her) -- here's my issue and I'm praying Someone has a clue. I changed the thermostat last week because it was stuck open and I'm weird in that I like things to work properly... anyway ran great day one....when I got home I popped hood to double check hoses since recently messed with & end connected to hard line/thermostat housing was spewing a small amount of fluid(obviously had just happened)-tightend clamp, cleaned up mess. next morning started fine, drove a mile or so & popped Bank1 & Bank2 lean code on computer(running fine, just popped codes). next morning started it to warm up before leaving and as soon as it got to operating temp it died and wouldn't start back up. MAS code popped so cleaned MAS. ran great. next morning exact same thing all over again. realized if I take off air intake at throttle body truck starts no problem & runs. replaced MAS. ran great on way home(15 miles)- popped lean codes again. next morning same again. checked/cleaned IAC, checked fuel pressure regulator at fuel line, not working properly, Replaced today. Ran like a DREAM!!! let idle, get up to temp, Beautiful :) so put everything back together, took shower, tried to start truck --start but wont stay running, then after a couple of times of that acts like no fuel until you let it sit & cool off. then fires right up if air intake off throttle body. Never had any problems until I put a thermostat in that worked.... WTH??? Ideas PLEASE....

 

4.0l OHV in '98

There are a few MAF codes, what was yours?

P0171 and P0174 means lean on both banks so is not an O2 sensor issue, and yes could be MAF sensor issue or when working on thermostat a vacuum hose under throttle body was pulled off and not reconnected.

There are also two Temp sensing devices on all fuel injected engines.
ECT sensor, 2 wires and only used by the computer
ECT SENDER, 1 wire, only used by dashboard temp gauge.

ECT= engine coolant temp

They are both just above thermostat housing, make sure the 2 wire sensor is connected.


On the crank shaft behind the pulley is a tone wheel, the Crank Position(CKP) sensor reads the "teeth" on this tone wheel, and that times the spark and fuel injection.
The wires from the CKP sensor run up around the water pump and passed the thermostat housing into the main wring harness.
If this wiring was damaged and is now heating up it could cause a no start, and/or engine to die, because computer can "time" spark, so will not start spark.

 

Hey Ron, thanks for the reply :) -- havent been on computer so I just noticed it. 171/174 are the codes. the ECT sensor & sender were also just replaced. BUT.... dont know if it could have anything to do with problem.... I was sold the sensor when sender was the Intended (& since harness fits right on both it wasnt noticed until I made them(parts store) do further research since my gauge Still didnt work (duh). I bought the correct(sender) and just moved the new sensor over so that both were new. could the sensor be sending incorrect info to the computer now? Truck is at a friends(real mechanic with high dollar computer) now so I cant go tinker. CKP is brand new also(changed a couple of weeks before therm when we changed the idler pulley because truck started shutting off running down road same day we realized pulley was coming apart-actually, Reason I noticed pulley.... looking trying to figure out the mysterious dying...) & I did notice how the wiring was looped by water pump and had my own thoughts about the harness.... anyway, hopefully Charlie's computer will tell us something...will post on here what we find
thanks
angie