New engine- missing, 15" vacuum

[capridude]

Same issue as before worn out engine was removed and rebuilt!

The only part on the engine that I re-used is the distributor/ TFI unit.
The vehicle doesn't stall, and starts fairly easily. Just a continuous missing of
the equivalent of two cylinders, warm or cold. The cap, rotor, spark plugs and wires are new, and the timing light picks up a steady flow on all wires!

Mechanically the engine is good (compression and leak-down tests), and the
valve and ignition timing is spot on. Fuel pressure is fine.

I ran KOEO codes, got 11 and 111- system ok.
Can parts of the ECU (main computer) fail, and still give out good codes?

About the only ideas left is to check the spark plugs, and run the KOEO test.

ANY ideas are welcome, this is driving me batty!

Cheers, Jeff

 

[holyford86]

KOEO only tests for hard faults, run the KOER test and see what you get.

 

[capridude]

Just ran the codes:

KOEO: 11 (okay)

KOER: 41- System lean - Fuel control
32- EGR not responding properly during test; EVP signal is/was low;
PFE shows low pressure, EGR not seating or memory, not seating
intermittently.

The EGR valve, and it's electronic 'sensor unit' have been replaced quite
recently. The vacuum lines are good.

The EGR valve seems closed at idle (If I suck on the actuating vacuum line, it will run poorly).

Puzzled!

Jeff

 

[pocket-rocket]

With having it missing and getting a lean code, I would almost think a couple injectors might be stuck shut.

 

[Tedybear]

I'd check the injectors as well. (had the exact same issue, turned out two injectors where plugged solid).

S-

 

[capridude]

Problem solved!

The EGR valve I installed new last year (and never run on the road),
was the cause of all this grief. It would not completely close!

Taking it back to NAPA, I expect a new one for gratis.

Cheers, JT