Fit Engine Modifications, Motor Swaps, ECU Tuning Reference Library for Engine Modifications, Swaps and Tuning

Running L15A with L12A2 ECU

Old 03-07-2017, 05:17 AM
New Member
Thread Starter
Join Date: Mar 2017
Location: Lahore
Posts: 1
Running L15A with L12A2 ECU

I have swapped a old L12A2 engine (had low compression in two cylinders) with a junkyard L15A (compression 180+ in all cylinders) . Tranny is CVT.

Both engines have same bore but L15 has a longer stroke. Could this cause an issue for the old ECU???

As per my understanding ECU would decide when to inject /ignite fuel based on CKP sensor output so longer stroke should not make any difference

All wiring connections from old wiring are grip to grip fit on the new L15A. Only the EGR valve is left unconnected because the old wiring did not have EGR support.

There is no check engine light. Only problem I am facing is
- slight misfire heard from exhaust at idle.
- slight jerking when accelerating between 80 to 100 Km/h
- slight delay in movement when gas pedal is pressed at car stopped
Old 03-10-2017, 04:09 PM
fittenmittens's Avatar
iTrader: (1)
Join Date: Jun 2016
Location: Charlotte
Posts: 42
can you get a cheap obd2 connector to data log? Can you check the % throttle body open reading at engine off with 0 pedal and then fully pressed? Does it change immediately? Have you verified the items that would cause these issues on a stock motor are good to go (good coils, spark plugs, valve adjustment). Have you blocked off the EGR port? I'm trying to picture it in my head but that could cause minor issues depending on what state it sits in on your car. A block off is incredibly cheap - get a piece of sheet metal, cut with tin snips and bolt on using stock bolts.
Related Topics
Thread Starter
Last Post
European Fit Forums & Clubs
09-05-2018 03:48 PM
1st Generation (GD 01-08)
12-05-2017 05:56 AM
Fit DIY: Repair & Maintenance
04-28-2017 02:11 AM
3rd Gen GK Specific Fit Engine Modifications, Motor Swaps, ECU Tuning Sub-Forum
04-24-2016 08:43 PM
Fit Engine Modifications, Motor Swaps, ECU Tuning
02-08-2016 06:27 PM

Thread Tools
Search this Thread
Quick Reply: Running L15A with L12A2 ECU

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.