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94 G13BA auto. Engine swap driveability issues; Diagnosis underway
Topic Started: Oct 29 2017, 10:57 PM (242 Views)
suzukitom
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Tom

Sweet running 94 Swift GA G13BA TBI 8v engine with in spec compression was swapped into 91 Swift sedan with 91 version of same drive train..which also ran well until its young owner did not notice low oil level causing engine to seize.

Full engine/tranny drive train swapped in including distributor, ECU, and re pinned engine harness.

Timing belt, distributor cap and rotor changed out before fire up. TPS and throttle body untouched.

Current symptoms:
Idle speed and quality normal.
Cold start normal
Engine will not rev above approx. 2000 rpm in neutral without causing ignition to cut out. Corroborated with timing light which stops flashing above 2000 rpm.. engine continues to run at WOT at about 2000 rpm but seemingly with fuel cut type behavior. Throttle body is sucking air as if starving for fuel.
Fuel pressure is 18 psi measured with engine off.
MAP sensor swapped eith no difference in behavior.
At steady 2000 rpm vacuum measured at MAP hose is 21 psi.
Base timing with jumper in place seems erratic at between +5 to -5 BTDC but seems to steady at around 20 BTDC until 2000 rpm when the timing light stops flashing.
Without diag terminal jumper in place the idle timing seems steady at 8 BTDC rising to scattered erratic advance when approaching 2000 rpm.

The exhaust system seems clear and no reason for suspecting a plugged cat.
Alternator is charging @ 14v and battery voltage is 12.5 volts at rest.

I am posting this for the person doing the swap.. So if there are any additional comments he will likely add them shortly..

Ideas/ thoughts?

I suspect multiple issues that are related to swap wiring going to the ECU but recall reading here about faulty TPS or bad CAS/distributors that possibly account for these types of symptoms.




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Me and my metro
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Did you use the 94 throttle body and sensors? When I put the 93 1.3 in my 91 car I installed the complete front harness and sensors. I repinned the dash harness to match and also the rear harness. I cut the automatic door locks out of the mid harness and plugged everything in. The 91 car should have had a mechanical advance distributor that thought for itself. Now you are trying to integrate a pcm controlled advance and the ignition is in the pcm.
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freegeo
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Quote:
 
Full engine/tranny drive train swapped in including distributor, ECU, and re pinned engine harness.


Can you give a little more detail about the above.
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suzukitom
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Tom

Me and my metro
Oct 30 2017, 10:45 AM
Did you use the 94 throttle body and sensors? When I put the 93 1.3 in my 91 car I installed the complete front harness and sensors. I repinned the dash harness to match and also the rear harness. I cut the automatic door locks out of the mid harness and plugged everything in. The 91 car should have had a mechanical advance distributor that thought for itself. Now you are trying to integrate a pcm controlled advance and the ignition is in the pcm.
Yes the complete 94 TBI equipped engine and auto. Transmission, and 1994 engine controls and sensors were swapped in also, along with its 1994 ECU (PCM). The 1994 electronic distributor, ignitor and coil were also used. The 1994 engine is a standard emissions version (ie. No ISC motor).

The repinning of the harness had to do with adapting 1991 and 1993 square vs round electrical connectors as well as ensuring that the 1994 PCM was connected to all of its sensors.
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freegeo
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Start with the inputs to the pcm. It is not seeing something. Make sure the wires are in the correct place on the sensor connectors.
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suzukitom
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Tom

Good advice... thanks.

When I went to look at this project yesterday..it felt a bit like playing one of those 'identify all the differences' picture puzzles.

Additional info:

The initial start attempt produced a CEL code 41 so the distributor was swapped with another distributor of unknown origin (sigh). This is being investigated..

I aldo don't recall seeing the noise suppressor installed. The wires are just hanging there.
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freegeo
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Take your own advice. If you can check the pcm connector pin out between the 91 and 94, see if it is the same. That could be your problem.

Did you only change the sensor connectors?
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suzukitom
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Tom

If this were my own project it might be easier to describe the work.

The person doing the swap has not yet posted to verify whether the ECU adaptation was strictly about changing the main connector or whether some wiring was also modified or omitted.

I have asked him to post... :popcorn
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freegeo
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Great. That would help
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Me and my metro
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The pcm on the 94 has several more pins, the timing is controlled by the pcm after 91. I did this swap successfully and you have to change a lot of harnesses.
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suzukitom
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Tom

Quote:
 
Additional info:

The initial start attempt produced a CEL code 41 so the distributor was swapped with another distributor of unknown origin (sigh). This is being investigated..


Update: The unknown distributor appears to be an OBD2 distributor from a 96 G13BA 8V. A proper OBD1 distributor for a 94 G13BA 8V is being sourced..
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