Vagabond22

Hi All,

I have been searching a lot of forums to find some help. It has taken me about a month to finally solve my pickup problem. I'm sharing my solution in the hopes that it will save people some time and money.

I have an 86 4x4 shortbox regular cab pickup with a 22RE engine and a five speed transmission, the symptoms were:
- hard to start when sitting for a while (started fine when warm or hot)
- rough idle for the first few seconds to a minute (smoothed out afterwards)
- not much power throughout the bandwidth

I bought the two volume factory manuals. If you do any mechanical work yourself they will pay for themselves in a few weeks.

There are a couple of things I eliminated right off the bat: the cold start valve, and the auxiliry air valve. They tested good and working. I also thought that both of these would not affect anything in the summer anyway. They are meant to supplement the fuel system when the outside conditions get colder.

I tested most of the sensors, electrical, and electronic components and everything seemed within spec. I set the timing to the 12° mark, and shorting the T and E¹ on the diagnostic block didn't make any difference (Followed the timing procedure). The only clue I got was diagnosis code 11- "IDL point in the throttle position sensor is off during diagnostic check" (Followed the output of the diagnostic code procedure). At first I thought that meant there was a short somewhere. The wiring, the ECU and Throtle Position Sensor all checked out.
I took a second look at the TPS and found that it was not adjusted correctly. At 0.57mm (0.0224in.) clearence between throttle lever and stop screw there was no continuity between IDL and E² connection on the TPS. I adjusted the TPS by turning it until there was continuity at those two points at that clearence. Then at 0.85mm (0.0335in.) there was no continuity, which is the way it's supposed to be. All the other TPS settings checked out.
I put everything back, reset the ECM and I got a code 1 which means everything is normal.
Then I set the timing again and this time I was able to set it exactly to spec.

Now it starts on the first try like a charm, idles good, and has more power.
I hope this helps some of you out there.

Jay351

I have the same problem. But its the TPS wiring that went bad. The Vcc wire... When I put bypass wire in place everything worked. Now I gotta tear the harness apart and find the short... yay.