99 Eclipse GS won't smog due to missfire

[Harleyjackjr]

Have 1999 Eclipse GS 2.0, just did an engine replacement and added an AEM longbranch cold air intake. Took it in for smog and the tech says it misfires at around 2500 RPM so won't pass the running test. Fuel pressure is good and plugs and plug wires are all new

 

[dsmreck]

what plugs and wires? did you check the gap? make sure connections were good? throw any cels?

 

[Harleyjackjr]

Not sure what throw any cels means. Plugs are NGK iridium BKR6EIX-11. I checked NGK's recommended gap and found that they were off by.010, re-gapped and it's better. Going to go get some standard Champions tomorrow and see if it helps. Thanks for the tip I think I'm heading in the right direction. May need a TPS too.

 

[jayson427]

Stick with NGK, I run just the standard gold with no issues. And a cel = check engine light. Why do you think you need a tps? Don just buy random parts you need to test them first.

 

[Harleyjackjr]

No CEL. I'll go with the standard gold then. Thinking TPS because it seems to have issues when it comes down to idle from higher RPM ranges

 

[dsmreck]

ok buy some ngk bpr7es make sure to gap them correctly as they with not come correct. and for tps you can check that with a multimeter.

 

[Harleyjackjr]

Should I gap them to NGK spec or Mitsubishi spec

 

[dsmreck]

just gap to .032 for stock. i run .023 on 30psi ngk plugs and wires with correct gap is a great setup.

maybe i should add how to gap plugs. you will need either a feeler gauge set or a plug gap tool. i like to tap the end of the plug on a table or hard wood surface and check gap after every time. if you go to far pry it back open and recheck until correct. you should feel the same drag on your measuring tool equal on all 4 plugs and your done. a very satisfying job.

 

[Harleyjackjr]

Thanks, I will give it a go and let you know what happens.

 

[fisher83]

If it idles rough, check for vacume leaks, maybe even take the iac ( idle air controller) out and make sure the tip is free of build up and that it seats correctly, make sure your throttle body is clean and the butterfly closes properly...start simple and cheap....then go buy parts as needed

 

[Harleyjackjr]

Fixed a couple of possible vacuum leaks, got different plugs and gapped them to stock spec, just waiting on a new IAC because mine tested bad and was caked with crud. It'll be here next week and we'll see how she fires. Thank you all for the assistance.

 

[Harleyjackjr]

Okay replaced IAC and idle is better but still a little rough, vacuum tested the EGR system and found had a leak so replaced it. Car is much smoother through acceleration curve but still a little rough on idle and has a slight misfire up to about 2800 RPM. I ohmed the coil pac and it tests okay, I'm at a loss now, wondering if engine manufacturer set timing belt wrong (ugh)