Help! I'm Stymied!, Only firing on #3 and # 4 Options

[DipShit]

1.7 D-Jet

Engine was running just great until about two weeks ago, sigh. Now only fires on # 3 and # 4.

I have cleaned every connection including all grounds. And I mean cleaned them good! The elecrical appears to be just fine. I get a good noid light at both # 1 and # 2. The injectors have tested just fine as well (I'm getting about 7cc in 15 seconds). I have 40lbs of pressure the 1,2 rail. The spark plugs are getting juice and fire.

I have installed new points, cleaned the triggers (which shouldn't have mattered because of the sequence) and set the dwell. I'm a tad under at 44 degrees, but again shouldn't keep # 1 and # 2 from firing.

The timing has to be close as it runs really smooth for just two cylinders.

If I pull the power to injector 3 or 4, I get a real good drop and she will die. If I pull 1 or 2 - no change.

If I add propane to the intake, I get a good response in higher rpm.

I had originally traced to the Temp II sensor and it failed, so I replaced it. A new one seemed to be the fix, but only for a moment.

I have good fuel, spark and air -

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I'm STYMIED (or just a REAL DIPSHIT)

[Katmanken]

Looking at the circuit diagram, everything we are talking about (except the distributor and spark wires) seems to connect through the wiring harness to the brain box.

From my computer days, connectors sometimes go intermittent as they (or the components) get warm....

Which brings up the questions, how are the connectors????

Have you checked the big assed connector that hooks up to the brain box? Do all the connections look like the others??? Any spread??

Hows about the connectors on the injectors???? Any look spread or different? You can usually pop the female connectors from the housing blocks with a tool such as the wire from a small paper clip.

Tried checking the injectors for performance when warm? From my solenoid design days, I learned that solenoids (aka injectors) warm up and the efficiency drops a lot. Which means that if a solenoid is marginal, it may have enough force to work when cold, but not enough to work when hot.

The other wierd problem thing that I have encountered is broken insulation on wires in the wiring harness. My daughters 1986 Volvo had the idiot tree hugger curse of biodegradable wiring..... Can you say a wiring harness filled with biodegraded insulation masquerading as non insulating insulation confetti pieces. The corroded bare wires randomly shorted together when the confetti shifted.....