I just bought the truck in my sig. I thought it was the fuel pump, but now it will start and idle...sorta. I have to keep the gas pedal to the floor to get it to start and then it will idle by itself (the RPMs will surge between 400 and 1400. It will die when you put it in gear). Just now when I tried to start it, it wouldn't start at all. The previous owner said it sat for about a year. And it has wiring issues, idk if that is related.

I have about 15 pages of this forum open right now and I don't have a clue where to start.

Possible ideas:
Fuel pump
IAC (?...it runs half decent if you hit the gas)
TPS
Coil
02 sensor
Crank PS


Any ideas where to start?

 

i'd check fuel pump pressure at the rail. should be 49 psi.

if that checks out, then based on idle surge, and a willingness to throw parts at it, i'd replace TPS for about $40 and see what happens.

 

OK will do. Thanks for the reply! Gotta buy a fuel pressure gauge. It's cool I enjoy buyin tools, actually I may be addicted.

Who like buying unnecessary parts though? haha Think you may be right. My luck it's both.

 

check your 99 to see if its got the valve on the rail.
you might be able to borrow the gauge from autozone, advance, etc.

 

No luck on the fuel pressure guage yet. But the fuel pump relay is good and you can hear the pump kicking on.

A buddy told me to spray some carb cleaner down the vacuum line heading towards the fuel tank cause it may be clogged. Would that help?

 

sounds like the TPS to me, since you dont know for sure or not go to your closest junkyard find a van, ram, or jeep with your motor, take TPS, put it in your pocket...ehhh i mean pay for it...and install it....i took mine off a jeep when it went bad...good as new, the jeep had 32,000 on the clock

 

NO! you need to check the fuel pressure, and have you cleaned or replaced the IAC and TPS? You need to try the things being suggested to you before moving forward in the trouble shooting stage.

 

Ok ok. But would the IAC keep it from starting? By my understanding, it only controls the idle. BTW Autozone wants $149 deposit for the fuel pressure tester. Pfft, I see that happening today.

 

First of all you can buy one for like 40 bucks(fuel pressure tester that is)

And second of all, your original post says it starts but won't idle(sorta). So which one should we go with?

 

You have to read the whole post.

Yeah they are I know they are $40-$50.