Renix 4.0 Raw Fuel Smell And Rough Idle

[1989 Eliminator]

Sometimes when i start my truck it starts fine. Other times its very rough and idles around 500 or less. Like it wants to stale. One time it actually did stale just from idling.

 

So i replaced the o2 sensor and tps because i thought those were tthe culprits. And i have 89,000 miles so a new o2 wouldnt hurt. My cps was brand new from mopar two years ago.

 

What else could this be? My exhaust smells very rich.

[onlyinajeep726]

Check the vac hose from the TB to the MAP sensor.  They like to crack with age causing a bad vacuum with to the sensor.  The MAP directly controls A/F ratio.

[1989 Eliminator]

I replaced all the vac lines. Including the map to tb one. I went through cruiser54's tips and did all i could for those too.

[cruiser54]

I'm suspicious of that tube also. Unplug it at idle when it's acting up and see if things get worse or stay the same. Also be sure the electrical plug is secure in the MAP.

[1989 Eliminator]

So today i started it and the rpms were weak and after a little bit of idling it staled

[1989 Eliminator]

I checked the map sensor readings:

ignition on, engine off: 4.7 V

Hot engine idiling: 1.66-1.85 V

Good ground

 

Tps readings:

Resistance from tps to firewall: .11 ohms

17% voltage difference

[1989 Eliminator]

Scratch that .11 ohm reading. Its 5 ohms. I had it on the wrong setting

[cruiser54]

5 is kinda high. 

 

Whaddya mean .17 "difference"?

[1989 Eliminator]

Eh i had the ignition on when doing the ohm test. I did the ohm test with ignition off and it was nearly zero. And my tps voltage on the C terminal was .8 and the input voltage was 4.7 volts. So, 17% difference.

 

My map and tps seem fine. I did some tests on egr and when i unplugged the electrical connection with the output hose off (hose from solenoid to transducer) there was vaccum. Which is good. But when i put the output hose on there was no difference in idle. The hose is new. So I'm thinking its the egr valve not operating correctly.