osb40000

I've spent many hours pouring through threads about smog on here, 4x4wire and pirate4x4.

Truck is a 93' with a 22re ~ 170,000 miles. Timing is set at ~ 7* (I could dial it back a bit, and it was set with the advance jumped). It has a recent tune up with new plugs, wires, cap & rotor. Failed initial smog on HC's at idle with 617 ppm (didn't give me a complete print out on their new machine, only listed where I failed).

I put in a new O2 sensor and changed my oil and here are the results.


RPM----------HC ppm-----/-------CO%-----/-----CO2-----/-----O2%
2500 ----- 195 (limit 220) - .26 (Limit 1.2) --- 14.50 --- .6

Idle ----- 1025(limit 220) - .96 (Limit 1.2) --- 15.00 --- .3

With the new O2 sensor (a denso) HC's actually went up (wondering if the new o2 sensor is good?). Obviously I'm running very rich at idle. Would you suggest that I turn the AFM screw to adjust? Also, my rig is running a little rough at idle, almost feels like a miss (when I threw the timing light on it it jumped around about a degree to a degree an a half).

I'm broke right now (just moved and looking for a job) but I can throw a compression gauge and multi-meter on a credit card if you think I should diagnose further (I have access to a FSM but am fairly new at fixing fuel injected vehicles).

Any help is greatly appreciated. Thanks!

89silverpu

Which O2 sensor did you replace the post cat or pre cat?

osb40000

My truck only has one O2 sensor directly before the CAT.

osb40000

Anyone have any ideas?

Georgiadave

I assume you are not showing any engine codes. I assume the engine was fully warm. Some ideas for a rough idle;

1. Clean the throttle body, especially around the butterfly valve.
2. Check to see if the coolant temp sensor is working, though if not, it should give you a code.
3. Not idle related - You might have a bad cat
4. Vaccum leaks - Replace all of the hoses Tighten the oil filler cap too.
5. Not likely, but your fuel injectors may be leaky
6. Try some Seafoam.

osb40000

Already used seafoam, the cat is less than a year old, hasn't thrown any codes, cleaned the throttle body. It might be the TPS (thanks NaeSLaS). Seems like a likely culprit.

GenXr

The slight miss along with the all the new parts, including the cat also make me think it might be your injectors. I had the same problems on the Nissan VG30E V6 engine as you are having and that's what it turned out to be.

G/Luck

osb40000

Hmm... I've never pulled the injectors on a toy. How difficult is the process?

Georgiadave

Pulling the injectors is easy, access is hard. Read the FSM on the sticky. I think you will have to remove the intake plenum assembly. Those little suckers are way down there.

I think there are some threads on the subject, they may give you more information.

osb40000

I pulled the vacuum hose off the top of the EGR (I believe that's how you check to see if it's functioning) and it didn't change a thing. Would a bad/clogged EGR present the problems I've had? Think this is the prob? I checked the TPS, the AFM, the fuel pressure regulator electronic gizmo. It runs like garbage at idle, like I said, almost feels like a miss. I'm going to guy a compression tester and check that. Like a few people have mentioned it could also be bad/dirty injectors.

I also looked at the charcoal canister and here are the results. I blew air through the gas port and air came out the bottom but not the small line. I plugged the bottom and blew air through the gas port and air came out the small line. I blew air through the bottom and air came out the gas port but if I covered it air would come out the small port. So... anyone have a clue what that means?

I'm not the best mechanic in the world but I'm learning, thanks for being patient with me guys. Your help, advice and knowledge are greatly appreciated.

Georgiadave

You should get an engine code 71 if the EGR system is not working. You test the EGR by putting some vaccum on it, not by disconnecting a hose. Read the FSM on troubleshooting the emission system. It will step you through sytematically to a fix.

osb40000

That's the thing that throwing me for a loop, I'm not showing and codes.

mr toytech

according to what i see in your readings, at idle is where your having problems. your co is a little high and your 02 is a little low. that means your actually running rich at an idle and that is sky rocketing your hc levels. so i would be looking for some thing that is making you run rich at an idle.

mr toytech

try taking the cold start injector out and cleaning the crap out of it. run some carb cleaner thruogh it and activate it with the battery so it can clean it out. when you get a good pattern from it and no leaks you should be good.