subaru issue help needed

[kevindouglas4130]

Hi Guys,

Im looking for some advise on an intermittent problem with my 86 Syncro, Subaru 2.5 swap.
Randomly it will lose power /choke while driving, it kinda “feels” like a fuel issue or a firing issue. When this happens I have to give it full throttle it will slowly pull its self up the rev range and when its in the top 3/4s rev range it will run perfectly then if it falls below a certain rpm it will happen again. For example if I cruise at 75/80mph its fine, if I fall below 70 mph it will start dramatically losing power.  I have to connect my scan gauge again to remember the exact rev range. And its intermittent that’s the annoying part. Whenever I had a mechanic look at it it didn’t happen so they can’t really or won’t help.  I think the only code the Diagnostics gives out is the TPS sensor.

Ive changed the: plugs, leads ignition unit. Throttle boys, and air control actuator (I think that’s what its called) changed the fuel pump and filter. Top end of the engine was also rebuild recently.

It did all run perfectly for years. My heads wrecked with it now I can’t find a mechanic that will work on it or figure out what’s wrong.

Any guidance would be much appreciated.

Kevin

[slowcoach]

Presume you've looked at/replaced the throttle position sensor? Where are you based? There must be a Subaru friendly garage close enough who can look at it for you. Difficult when it's intermittent though hey

[silverbullet]

If the tps is knackered then you may well get spurious values being fed to the ecu at anything other than larger throttle openings (where there will have been less use/wear)

If the fault code says tps, then replace the tps.

Who did the conversion or the wiring harness mods?

What age of 2.5? Quad cam or a twin cam? Which ecu? Have you tried the RJES waterkooled forum or fb page?