Rich at idle and rev

[3tcpower]

So, my car is running rich at idle and when revving to 2500. When I got the car it ran rich and had other issues. I fixed them and tried to get emissions done (the place I go to doesn't have 4wd testing, so it is tested without boost). Well, it was double the max reading at idle (idle was a little over 800) and 4 times the max at 2500. I will post exact numbers and details later.

Since then I have replaced the O2, plugs, wires and rechecked my IC pipes. No leaks and they are securely clamped and I seafoamed the engine. Also, the plugs are gapped at 30.

It also has a new cat (not high flow).

With everything I have done, it still smells rich and I dont want to take it to get retested till I know its better. Any suggestions on what to check?

Also, I have no logging tools at the moment

 

[chico904]

When you say you checked your IC pipes, did you just check the couplers to see if they were tight? If so, you still need to do a boost leak test.

 

[3tcpower]

I checked the couplers cause they are new and the pipes are good. I figured new couplers wouldn't leak unless not secure. I will try and do that in the coming days though, just to double check. I am also just trying to get other ideas.

And on a theory related question, why would the car run rich at a high rev with a boost leak? I always figured it would run lean cause more air would get pulled in that was unmeasured.

 

[knochgoon24]

1. Fill out your profile so we know what you've done to the car. That will at least give us a place to start.

Before you drop more money into just randomly replacing parts, you might want to get a wideband and see if you are truly running rich. Depending on your mods, the fix could be simple.

 

[3tcpower]

The reason There is nothing in my mods is cause there really are none. The car is bone stock, except for the IC piping I replaced with metal and a MBC.........k, maybe I should fill it out.

Also, I wouldn't really say I have dropped money on things unneeded, besides the O2 sensor. The plugs were fouled, wires were garbage and the IC pipes I did was to replace the hoses I didn't care for. I have an issue with using rubber hoses for boost. Too hard to spot where an issue might be in my opinion.

Thanks for the feed back so far.

A wideband would be nice, but I'm trying to avoid dumping money in when I know its running rich. The old sniff test. The exhaust smells the same today as it did when I got the emissions done. I may have to just invest in the things needed for a logger. I assume this would help diagnose my issue, yes?

Also, any insight on the question about running rich with a boost leak? Just curious.

 

[3tcpower]

Here are the results of my emissions. If any one can shed some light on how to improve this. I figure there has to be some maintenance related items I may not have addressed.

 

[knochgoon24]

As you go into boost, air leaks out. That air was already measured by the MAS. The car injects enough fuel for the the air measure at the MAS, but some of that has leaked out, so now there's extra fuel, and it runs rich.

 

[3tcpower]

As you go into boost, air leaks out. That air was already measured by the MAS. The car injects enough fuel for the the air measure at the MAS, but some of that has leaked out, so now there's extra fuel, and it runs rich.

That part makes sense, but I was under the impression that most cars do not boost when you are in neutral. Is that line of thinking wrong?

 

[knochgoon24]

Didn't notice that your were particularity talking about rich when neutral. That could be anything from a bad MAS to an unplugged sensor.

 

[Jeff99GS]

DO A BOOST LEAK TEST ASAP

You have to pressurize your whole Intercooler system and check for leaks.

DON"T just go around making sure the clamps are tight?!?! WTF

It could be leaking from Vaccum hose connections, Throttle body or anywhere else.



Also check the coolant temp sensor.

 

[3tcpower]

I understand that about a boost leak test, but how does that cause it to run rich when idleing since there wont be a boost leak without boost.

I will check into the sensor.

Is there a way to check the MAF?

 

[Jeff99GS]

When you start the car thr turbo is always spinning. So at 2500 RPM you might not have BOOST but the Turbo is still Blowing MORE air than the engine is Sucking.

All the air that the Turbo pulls IN is being metered by the MAF near your air filter. If ANY of that Metered air is lost, then the car will run rich. Because the MAF already metered that air and will Add the proper fuel trim for that amout of air.

Im not saying that'its for sure a boost leak, but its the easiest thing to check first.

Is your BOV recirculated?

do you have any check engine lights on?

 

[3tcpower]

When you start the car thr turbo is always spinning. So at 2500 RPM you might not have BOOST but the Turbo is still Blowing MORE air than the engine is Sucking.

All the air that the Turbo pulls IN is being metered by the MAF near your air filter. If ANY of that Metered air is lost, then the car will run rich. Because the MAF already metered that air and will Add the proper fuel trim for that amout of air.

Im not saying that'its for sure a boost leak, but its the easiest thing to check first.

Is your BOV recirculated?

do you have any check engine lights on?

The BOV is recirculated. Also, no check engine light. Its just wierd cause the cars seems to run fine when driving. No fuel cut or hesitation........but I haven't really pushed it hard either.