Well, I got my Apex’I PFC about a week and a half ago, that install went fine. Today I got my new fuel filter and O2 sensor, so I decided to install them (never got to fuel filter)

After I’m done with plug wires, plugs, and O2 sensor, I decided to start it up. Now I get this loping idle like the car is ported or something. I double checked all the plug wire connections and they are all good.

Do I have to reset the PFC or something? I tried doing that but it doesn’t seem to want to ‘learn’ the idle, it just continues to lope. Vacuum is bouncing between 12 and 14 in. Hg (normally 19-20 at idle)



Only engine mod is a downpipe. What am I doing wrong?

 

did you cut the required wires from the harness? or depin them?

stepin up in your autoX class, eh?

 

No, i didn't cut the wires, the car was running smoothly with everything intact before so I didn't bother cutting them.

class, yes, i'm certainly upping the classing now, although my local autox club basically just has everyone show up and compete LOL

 

interesting...could you have a vac leak around your throttle body? I can't even begin to think out good plugs and wires can effect idle this much?!?!


could it be possible a plug wire is no good...maybe check you are getting spark on all 4. O2 is probably not the cause...

 

Happened to me before.

I noticed one of the plug wires were on but not "snapped/clicked" on the plug. Make sure all of them are clicked on the plug.

 

Id be tempted to re-install the old O2 sensor (maybe the new one is broken,, or possibly the old one was broken and now that you got a new one installed the problem relating the the wires that need cutting on USA power FC installs are now highlighted)

 

I agree. Or that you bumped the MAP sensor line off doing your work....

 

I thought about reinstalling the old O2 sensor, but i got an aftermarket from Rx7.com so i had to cut the wire to install the new one. I'll check the MAP sensor tomorrow and I'll also check for bumped loose vacuum hoses around the TB. The engine seems to rev smoothly, just doesn't want to idle smooth.

 

I'm an idiot. It was the MAP sensor line knocked off. I feel like a dolt now, its always the first thing to check! I guess since mine has never come off, and i had just done work to the car i was more concerned that i had crossed the plug wires or mucked up the O2 sensor install.

Thanks everyone.

 

Glad to hear you solved the problem.

Its mostly always the obvious thats the cause to a problem.

 

It's ok. It's a common thing for people to knock the MAP sensor line when dealing with the spark plugs/wires. You only do it once as you know to check it after that.

BTW, did you change the plugs from the top or the bottom?

 

I did it from the bottom, pretty easy that way. I did one plug at a time, and changed one plug wire at a time as i did each plug.

 

I've got ask, having noticed the location of the MAP sensor almost on the firewall of my 1994. I change the plugs from the bottom as well. (Quite frankly I get nausea doing it. Something about the smell of exhaust and hot oil with my nose stuck up there) In any event, how do you manage to knock off the MAP lines when you are working on the totally opposite side of the car????????? Sounds like something I'd manage to do.

 

Even though your changing the plugs from the bottom of the car, you have to work from the top as well when your replacing the spark plug wires. You have to remove the TB to attach the wires to the coils, which is typically when you knock the hose off the MAP sensor.

I replaced my plugs and wires ~ a month after I purchased my car, and made the same mistake. Luckily we have Majic on the forum! (He replied to my thread like 2 minutes after I posted it!)

-Alex

 

I see. I missed the fact he was replacing the wires. The coils would be a most difficult reach from the bottom of the car! Removing the TB to get to the point where the wires attach to the coils? I hope that's not as difficult as it sounds from my limited perspective. I've been contemplating replacing my wires as well.

 

It's not that difficult, just take your time and be careful not to break the TB gasket.

I just did a test run in the car, it's running much better now and it's boosting a perfect .689 bar. Before the the work it was going a bit over to .72 bar.