Emissions problem

[4G63 For Me]

I'm having problems passing emissions. The only test I'm failing, though, is hydrocarbons at idle (it passes at 2500 RPM). They're generally around 280 or so and spike to 400-500 occasionally, then come back down. The limit is 220. I leaned it out a bit at idle, I raised the idle to 1100-1200, I retarded the timing as much as possible at idle, unplugged the ISC (in case it was bad), still couldn't get them to stay below 220.

We had it below 220 a few times, but it would jump to 400-500 every 10 - 20 seconds.

I'm pulling my hair out here. Any suggestions?

Things I've done:
-replaced plugs
-replaced wires (went back and car was 10x worse, put better wires back in)
-cleaned air filter

The car has always passed emissions before. The only changes since last time are cams (272 HKS) and DSMLink. Right now, I am running 93 octane gas with an octane booster added. Do I need to fill up with 85 or 87 octane? What do I need to do? I've spent waaaay too much money already on this (seeing how as of Jan 1, 2007 they get rid of emissions testing here)

 

[DSM90AWD]

I notice an aftermarket FPR is not listed with your Walbro255. I suspect if this is the case you will be running some pretty rich low trims (stock FPR overrun), especially with the lower idle vacume you'd get with larger cams which would also boost your FP at idle.

If you have an AFPR, may want to lower your base fuel pressure a few PSI to lean things out for the next test

 

[4G63 For Me]

I notice an aftermarket FPR is not listed with your Walbro255. I suspect if this is the case you will be running some pretty rich low trims (stock FPR overrun), especially with the lower idle vacume you'd get with larger cams which would also boost your FP at idle.

If you have an AFPR, may want to lower your base fuel pressure a few PSI to lean things out for the next test

You are seriously the man. I have an AFPR to be installed, but the last TWO (yes, 2) install kits I've ordered haven't had the right parts to install it. Before I took it in for the emissions test, I knew I needed the AFPR.

I figured that was the case beforehand and kind of lost track of that throughout this BS. I will get the right parts to install the AFPR (I'm almost certain that and a rewire of the fuel pump will help my knock problem @ 5000+ RPM) and then get it retested.

I really thank you for the input. You definitely get a + rep points.

 

[andytalon]

What is the install kit missing? What one did you get and where from. I got mine from Import Evo. and it had everything for it... maybe I can help with the install??

pm me or reply

 

[4G63 For Me]

Update:

I got the AFPR on, lowered the base pressure to about 40 PSI, put 87 octane in the tank, unplugged the ISC and got it tested again.

Failed, yet again, this time I didn't pass either idle or 2500 RPM hydrocarbon test.

I've since taken the AFPR off (the fuel return line came off) and put the stock one back on.

Any suggestions? Maybe I should plug the ISC back in during emissions?

 

[andytalon]

Use 93 octane why would you switch???

 

[DSM90AWD]

Did you reset the ECU after you added the AFPR to reset the LTFTs ?

If were me, I'd:
- Reinstall AFPR and adjust Base FP to 42psi
- Check/fix any boost leaks
- Check/fix any exhaust leaks
- Refill with 91+ ocatane gas
- If EGR blocked off, return to operation
- Check/set base idle speed (with ISC plugged back in)
- Reset ECU/LTFTs
- Drive 50miles and recheck LTFTs / Adjust DSM-Link Fuel settings if out of range.

A buddy of mine recently went thru a similar issue with his car. The emissions tech worked with him tryign to get it to pass which they did by disconnecting the BOV return line which allowed unmetered air into the system (lean condition)