Significant Idle Decrease after warm

[cferry7]

Hello -

1989 toyota pickup 22R, 4 cylinder, 4WD , 1 ton

Two issues :
(1) After 20 minutes of Highway or City Driving the Idle becomes much significantly lower, almost to the point of stalling out.
(2) After approximately 40 minutes of driving city and highway - First Gear becomes much much lower in power and torque. Second Gear and Above appear normal after this drive time. Concern ?

Any suggestions , areas to look into ??
cferry7

 

[flyinhawaiian01]

Check for codes
Check plugs color (rich?lean?)
Check timing (too advanced?)
Check for vacuum leaks when cold
Check injectors

 

[penbergm]

Tps.

 

[cferry7]

Distributor Pickup Coil

1989 Toyota Pickup 22re

I have found a thread on a recent search, concerning Hesitation and Poor Idle after engine Warm- discussing the Distributor's Pickup Coil, Signal Generator.

I measured the resistance of the DIST. Pickup Coil.
Cold - 178 ohms, 5 minute engine run - 180 ohms, 15 minute engine run time - 194 ohms. These may be close read values, since I am not looking at my note piece of paper. Either way these are off the chart - Specification says 140 - 180 ohms.

Will most likely be replacing this Pickup Coil, today.

I would also like to check the EGR system.

Yours or Others Suggestions . . . .

 

[cferry7]

Codes

1989 Toyota Pickup 22RE

Two Codes which have been on this Truck OFF and ON for several month's are : Code 25 / Code 26 related to Rich / Lean Air Fuel Ratio.

These two Codes may be related to a Exhaust Pipe Hole/ Crack in which we have bandaid fixed, which exists just prior to the Catalytic Convertor.
Hopefully will be having this Pipe Permanently Repaired prior to Winter.

Still staying w/ diagnosis of DISTRIBUTOR Pickup Coil , at present.

Suggestions / Comments .....

 

[cferry7]

9.28.15

Purchased the New "Pickup Coil" a
Duralast p/n JA1008.
Measured resistance of this new part , it read ~ 235 ohms. The Chilton Repair Manual says 140 - 180 ohms per spec.
Why Does It Measure This ???

 

[cferry7]

Decided not to install this new Pickup Coil -
Until I find out WHY Resistance reading is
Explained.

Original Dist. Pickup Coil reads 178 ohms with
Engine Cold.

Have Done Today :
1) Checked EGR Valve source Vacuum
2) Checked various other Vacuum Hoses
3) Cleaned w/ Rubbing Alcohol the Face (Pickup Magnetic Reed portion ) of Original Dist. Pickup Coil
4) Cleaned Distributors Rotor
5) Increased Idle w/ Idle Set Screw

Distributors' Pickup Coil Reed was so black in dirt grime that two Q-tip ends soaked in Alcohol
came away dirty and black !

From the way the Truck was Idling prior to and during this activity,today - Engine was almost stalling. It appears
that Items # 3 and # 4 above, made the Idle Stable !!!

Test Drive after these maintenance steps - Resulted in a Good Solid Idle and Notice-able More Acceleration Power.

To be Continued . . .