mookdizz

I have a 1990 Comanche with a renix 4.0L. Truck has been running good for around a year. I got fuel last the other night and drove it home. Started up first thing in the morning and it idled VERY low (~300rpm). I keyed it off and attempted to restart, sputtered but nothing. It will sputter a bit on the first crank after I let it sit for awhile but after that I get nothing. I have verified the following...


Fuel pressure is ~40psi when cranking.
Spark plugs are gapped correctly and sparking.
Battery is good, new interstate within 6 months. Cranks strong.
Grounds were freshened per Cruisers cheat sheet around 6 months ago. New larger negative battery cable installed as well.


Where should I look next? crank position sensor? and if so, how can I test mine? Any info would be greatly appreciated.


Thanks!
Mike

cruiser54

To test the CPS, go to www.cruiser54.com and see tip 7.

Have you done Tip 3 yet?

Or 5?

XJwonders

very nice.

cruiser54

The website?

XJwonders

yes

cruiser54

I had to do it. Maintaining my stuff on 4 forums got to be too much of a pain.

XJwonders

of course. It's brilliant idea

cruiser54

Ross helped a ton. Couldn't have done it without his "geekness".

mookdizz

Thanks Cruiser!


I performed #3 when I did my grounds. I will run through it once again since I am going to perform #5.


If nothing comes back bad, I will follow the steps on there for CPS. I MIGHT have time before work tomorrow, we will see though!

mookdizz

I performed 3 and 5 again. Checked CPS, it shows .38V. I also reset the TPS to the proper spec. It tries to start but no dice. Should I try cleaning that CPS, or just get a new one with that voltage?

cruiser54

I've seen them run at that CPS voltage. You could drill the upper hole per Tip 7 for the heck of it.

Have you ever checked your fuel pressure or checked the ballast resistor connections?

mookdizz

i have 40 psi fuel pressure, ballast resistor connections are good as well. Ill try drilling as you mentioned

mookdizz

Well, no room to drill the hole so I just installed a new cps. It tests .55v when cranking. Still no start. I tried cleaning the coil connections and sprayed starting fluid down the throttle body. No start there either. That leads me too believe ignition related. Any checks for ignition components? Or other ideas/opinions?

cruiser54

Look inside the dizzy.

mookdizz

Well, I checked through the distributor and everything was looking good. I verified that my spark was good again. We were pretty sure it was flooded so we ran it wot with the fuel pump wiring disconnected at the ballast resistor. Then checked to see if the IAC was opening... bingo! replaced with a spare from a spare throttle body a buddy had, and shes back on the road. Honestly the first time I have seen IAC cause a full on no start... Thanks for all the help!