Engine not running right

Discussion and technical advice the SW20 MR2. 3S-GTE, 3S-GE, 3S-FE etc
Anything and everything to do with maintenance, modifications and electrical is in here for the Mk2.

Moderators: IMOC Moderators, IMOC Committee Members

Post Reply
Tomo3003
Posts: 2
Joined: Tue May 16, 2017 5:39 pm
Location: Cornwall, UK

Engine not running right

Post by Tomo3003 »

Hi all i'm in the process of swapping a turbo engine into my N/A, hit a snag though... It won't idle with the AFM attached.

It's Rev 2 Turbo engine pretty much stock. The engine starts and runs fine without the AFM attached, with it attached it turns over and if your quick enough to catch it you can hold at 2k revs and it runs fine.

Tried 2 AFM's, 2 ECU's had a mutimeter on the loom, checked the IACV and the TPS and all is right there. There are no vaccum leaks and the OBD1 shows no error codes.

Only thing we can find is it runs a little bit rich bit that shouldn't cause this problem.

Anyone ever had anything like this of can think of anything that it might be. Starting to lose my rag now as it's my daily car so I need it back on the road ASAP.
mr2magic
Posts: 643
Joined: Fri Apr 09, 2010 9:33 am
Location: Hannover, Germany

Re: Engine not running right

Post by mr2magic »

What wiring loom (NA repinned/turbo) and ECU are you using?
Tomo3003
Posts: 2
Joined: Tue May 16, 2017 5:39 pm
Location: Cornwall, UK

Re: Engine not running right

Post by Tomo3003 »

Both body and engine loom got changed to turbo looms and the ECU'S are OEM Rev2 turbo ECU's
mr2magic
Posts: 643
Joined: Fri Apr 09, 2010 9:33 am
Location: Hannover, Germany

Re: Engine not running right

Post by mr2magic »

ok. This sounds suspiciously like a large vacuum leak. Please check every pipe and hose after the afm right up to the throttle body. Also check the pipes from the hose before the turbo that go to the valve cover and the IACV

Then also check the wiring on the connector for the AFM. How's fuel pressure and when did you last change the filter?

Check your static timing - set the crank to 0 BTDC and make sure the cams are aligned correctly.
Post Reply

Return to “MR2 MK2 1990 - 1999 NA & Turbo”