when i bought the truck it had a small idle issue, now its spitting and sputtering when i get on the gas, its missing terribly just did a complete tune up, its started doin it right after it rained pretty heavy and has been acting wierd ever since. possible water in gas tank? im open to any suggestions. Thanks!!!!

 

Define "small idle issue." Was it stumbling? Was it missing? Was it idling low/high?

What all did you do for a tune up? Did it involve replacing the spark plug wires, and if so, are you sure you've got the right wires matched to the right cylinders?

 

for the idle problem its loping up and down up and down and then dies and my oil pressure gauge goes down and up only when im in drive when I put in park or neutral it idles fine, it only does it when I come to a stop in drive , as for the tune up I did plugs wires cap and rottor button all the wires are in the right spot cause I did em one by one and when I started it up it ran fine.

 

These next few things are on the assumption that it's fuel injected, since you didn't specify:

1) Check the idle air control (IAC) valve. With the engine running and up to normal operating temperature, unhook the wiring harness. If the engine starts sputtering and dying, it's good. Fuel Injection Technical Library » Idle Air Bypass (IAB)

2) Check the fuel pressure regulator. Simply pull off the vac line and if you smell gas or see it dripping out of the vac line, it's bad. Fuel Injection Technical Library » Fuel Pressure Regulator (FPR)

3) And, of course, check the trouble codes. Personally I'd just recommend buying a scanner b/c they're only about $30, but you can always do it the old fashioned way: Fuel Injection Technical Library » How To Run a Self-Test

 

Sorry about that, it is efi. thanks for the information, I was gonna put a new IAC on it tomorrow I took the one on there off it was a little gummed up.

Are you talking about the vac lines on the tank?? (havnt owned truck long still getting to know it)

and the truck is not OBD II where can I get the scanner, I read some where that it is a two prong plug and you complete the circuit a the check engine light flashes the code in short and long flashes

again thanks so much for your help

 

A little gumming/varnish is normal. I'd try cleaning it before replacing it. A can of carb cleaner w/ a straw should do the job nicely. No sense in replacing it if you don't need to.

No, the vac line that attaches to the fuel pressure regulator. It's at the back side of the motor and mounted on the fuel rail. Look at the photo in the link I provided you- it attaches to the nipple on the top of the regulator.

I got my scanner @ O'Reilly for about $30. But NAPA, Advance, Auto Zone...just about any parts store should carry them, with varying brands of course. Equus Innova 3145 - Digital Code Reader | O'Reilly Auto Parts

As for pulling the codes yourself, without a scanner- that's the link I provided you with in item #3.

 

i put a new idle air control on it, new coil, and fuel filter, the missing has stopped but its still got the loping problem, im gonna smoke test it this week

 

And the FPR?

It may also be useful to just get fuel pressure readings.

 

subscribing

 

Fuel pressure at idle is 32 pounds as well asat 1500 rpm

 

If it's maintaining that pressure, you're fine. To confirm that, you'll want to ground the fuel pump pin on the diagnostics plug (see picture below) and run the pump for about 10 seconds. Then kill the pump and check the fuel pressure every 15 seconds for one minute. If it doesn't lose more than 5 PSI within 1 minute, it's good.

 

It only has that when its running when the truck is off and i cycle the key on fuel pressure is only about 3-5. Also where is this test port located
Thanks