Issues on a 93 Turbo Legacy auto-to-manual swap

[DaveK]

Yeah, by the time I got the car, all of the auto stuff was gone (other than the TCU), so I'm not sure I would've been able to do that. There are a couple auto cars in the yards around here so I could go pull some parts, but hoping there's some other solution to try.

Good idea on the throttle cable causing the hanging revs. I'll loosen that back up a touch tomorrow and see if I can make some progess. Guessing that doing that will only make the car more prone to stalling though. If I'm seeing idle speeds that are very low, is messing with the IAC an appropriate thing to consider?

Thanks!

Dave

[Legacy777]

Dave,

Here's my two cents....it sounds like you may have two separate issues. When done properly the ECU acts just like it would from the factory as a MT. So if you've done all the stuff in my write up, you should be fine with the swap.

If you have idle issues, sticking and stalling, then I agree you should probably look at the IAC valve. The other issue is the LW flywheel....it takes a little bit for the ECU to learn how the engine reacts with it and compensate the idle. If the IAC valve is sticking or not working optimally, then that could be causing the stalling. The rpms sticking again points to a possible IAC valve issue.

I don't recall if you already mentioned this, but have you checked for any codes?

[DaveK]

Quick update on the prior issues, and some new ones. I pulled off the pipe going into the IAC and hosed it down with carb cleaner while the car was running. All of a sudden my adjusted idle was waaaay too high. I dailed the throttle stop back to where it used to be and the stalling thing is 95% cured. I still have a stupid low idle, like 600rpm, but its no longer the massive pain in the butt I had before. Also, I got a check valve installed in the line to the brake booster, so if the car does stall...I still have vacuum assisted brakes.

Now trying to pass Colorado emissions. I'm 0 for 4 so far. Quick details on the swap again, its an EJ20G swap running the EJ22 ECU. I'm running a Hallman MBC set all the way down so the car peaks at ~5-6 psi. Only other "upgrade" is that the car is running a cone filter and has some sort of aluminum turbo inlet pipe.

Took the car in as I've been driving it, but dropped in some E85 in hopes of it helping me to run cleaner. Running a mixture of about 30%:

HC 1.9 vs. 1.2 failed
CO 8.5 vs 15.0 passed
CO2 398 (no limit listed)
NOX 7.0 vs 3.0 failed

I borrowed a WRX downpipe with 2 cats and took it back and dropped in a few more percent of E85, estimated to be somewhere between 40% and 50%. Actually had two tests done back to back on this trip because the guy driving the car got a "failed to accelerate" warning because he was trying to lug the motor in 3rd gear and it wouldn't pick up the speed quick enough. I pleaded that they bump the revs up when driving the car so they wouldn't be trying to make boost, but was like talking to a brick wall...same basic result as the next guy driving the car did the same thing.

HC 0.05 vs. 1.2 passed
CO 0.001 vs 15.0 passed
CO2 410 (no limit listed)
NOX 5.7 vs 3.0 failed

Did some head scratching and after realizing that failing on NOX indicates high cylinder pressures and/or temperatures, the lightbulb went off. Maybe I was seeing high temps because the car was actually running lean. So, I ran that tank down to just about empty and filled the tank with 91 octane (highest we get in Colorado). I figure that put the car back at ~12-15% ethanol since all fuels here are E10 and headed back for another shot:

HC 0.03 vs. 1.2 passed
CO 0.17 vs 15.0 passed
CO2 418 (no limit listed)
NOX 4.7 vs 3.0 failed

So, now I'm stumped. I took the car into a local shop to have it looked at and they suggested swapping in new plugs, so that's now done, but the car still has the same hesitation issues as before, so I'm not sure its likely to run any better. I've wondered if the timing could be off, but have been told its not likely the culprit because the car would barely run.

Other thought is that the fuel presure regulator isn't bumping fuel pressure as manifold pressure changes...but the vacuum line is hooked up, so if it were leaking, wouldn't I have some other issues/symptoms?

Thanks for any input you can offer!

Dave

[Legacy777]

Dave,

You're correct in that NOx is formed from high cylinder temperatures. What type of test are they running? Is it on an AWD dyno?

Have you changed out the spark plug wires?

Timing may be an issue if it's off it could be allowing more NOx to form in the cylinder. It wouldn't hurt to check the timing.

[DaveK]

Yep, they do the test using an AWD dyno. They basically simulate a drive around the block and getting onto the highway.

I have not changed out the plug wires as I was thinking of doing a WRX coil swap at some point soon. I'd assume that if I had spark blow out issues that I'd see lots of unburnt fuel and high emissions as a result.

Dave

[Legacy777]

Well....you mentioned hesitation, which is why I asked about the plug wires.

Are they getting into boost when they simulate getting on the highway? I honestly believe an acceleration test is not a fair test. The test needs to be a steady state test.

[DaveK]

Ahh, gotcha!

They are getting into boost, but it's been my experience that turbo cars are more sensitive to the person driving them. They also shift very low in the rev range, so on a turbo car, it's often that the boost gauge would just be sitting right around zero...when the car is trying to richen things up, but then they shift before the car gets much of a chance to make boost. They have a speed curve that they are following, so its not like they're drag racing for best 0-60 times or anything like that.

I agree wholeheartedly that the test sucks, but its what we've got to put up with living in Denver.

Dave

[Legacy777]

That's BS IMO.

Lugging a turbo car does not work well.

Have you tried a different shop to see they are a little more friendly to try and get you to pass.

[DaveK]

They are state run facilities.

[Dave_J]

Dave, looks like your trying but the car is not. Just for giggles try regapping the plugs a bit shorter, like 0.035". It will make the spark a bit hotter and easer to jump the gap. The factory gap of 0.041" is a big gap, being that the coils are firing two plugs at 0.041", not one. Its like the coils are seeing one plug gapped at 0.082". Over gapping plugs on Turbos and NOS cars is a big problem.

[DaveK]

Sorry guys...I hate when people do this. I got it figured out but forgot to post up with the cause of the problem. Here it is in case anyone else finds themselves in a similar position:

I replaced the fuel filter and I passed! It was so clogged up that you couldn't blow through it at all.

I also bought a new fuel pump, but haven't had a chance to swap it yet and wanted to try and isolate the problem.

Thanks to all for offering up ideas!

Dave

[Legacy777]

Dave,

Glad you got it sorted out. That's interesting that a clogged fuel filter would cause that problem.