Smog - Fix High HC - Hydrocarbon

[AresROC]

I have a '93 Paseo with 5E-FE. Took it to smog yesterday, and it failed the HC low-speed Idle Test. Legal limit is 220, and I got 520...

Question is, should I give up and junk it, or should I try to fix it myself?

The car has 170k miles on it and is not in too bad a shape. It must have failed the emission test for a while, because when I looked in the throttle body, it is full of thick carbon build up. I was told it had a broken timing belt once as well, so I don't know if on the 5E-FE that could cause bent valves or not.

I have researched and found someone else who had good luck with something called a "seafoam". Was wondering if anyone had experience with this and should I give it a try? Is 520 a really bad number for idle HC?

-Paseo newbie...

[bkftl]

I've heard of places where if u pay em enough or just talk to them. You will "pass" the emission test ... *Cough Cough* If you know what i mean...

[AresROC]

Yes that would be the "EZ" way

I was also thinking drilling holes in the exhaust before OR after the Cat. That is, just "thinking".

[96paseo]

A broken timing belt will not cause bent valves. 5EFE is a non-interference engine. At your mileage, I would recommend the following.
1.New plugs
2.New wires
3.New cap and rotor
4.New air filter
5.STP Oil treatment
At your mileage, your likely getting some contribution to the HC number from burning oil. Put a can of Seafoam in the gas tank. Get the deep creep and clean the throttle body as well. An old toothbrush and a few rags will get the job done. LOL at drilling holes. You'll probably fail for noise if you do that. Here's a thread on cleaning the TB.

How to: Cleaning Throttle Body -4 Cylinder Engines- With Pictures

[AresROC]

Originally Posted by 96paseo

1.New plugs
2.New wires
3.New cap and rotor
4.New air filter
5.STP Oil treatment

Sweet! I will do all that. I got some Techron stuff in the gas tank now, will try SeaFoam in the next tank. Should I try the SeaFoam or STP Oil treatment in the crankcase first? I tried cleaning out the throttle body with carb cleaner first, but not having much luck. It's amazing watching the black streak of carbon flowing out of it!

[96paseo]

Originally Posted by AresROC

Sweet! I will do all that. I got some Techron stuff in the gas tank now, will try SeaFoam in the next tank. Should I try the SeaFoam or STP Oil treatment in the crankcase first? I tried cleaning out the throttle body with carb cleaner first, but not having much luck. It's amazing watching the black streak of carbon flowing out of it!

Save the STP and add it right before you go to inspection. That way its working at its best when you get there.

[AresROC]

Oops this car already had new Plug wires & OEM distributor in '04, 6 years ago. The air filter is fairly clean also. It has a rough idle at 800 rpm. Under braking it feels like it's about to stall.

From pulling the spark plugs, I noticed the 2,3 cylinder plugs had more carbon buildup on it than the 1 & 4. Could this indicate the source of the issue? The PCV hose doesn't seem to be plugged...

I was wondering if I need to go with one of these "big bucks" items: O2 sensor, Idle Air Control Valve, Cat... (or drilling, lol, can't get it out of my head )

[96paseo]

Originally Posted by AresROC

Oops this car already had new Plug wires & OEM distributor in '04, 6 years ago. The air filter is fairly clean also. It has a rough idle at 800 rpm. Under braking it feels like it's about to stall.

From pulling the spark plugs, I noticed the 2,3 cylinder plugs had more carbon buildup on it than the 1 & 4. Could this indicate the source of the issue? The PCV hose doesn't seem to be plugged...

I was wondering if I need to go with one of these "big bucks" items: O2 sensor, Idle Air Control Valve, Cat... (or drilling, lol, can't get it out of my head )

Don't replace the cat, O2's or IAC unless the CEL is lit and you've checked the code. A new cat isn't going to lower your HC. 6 years is enough time for the cap, rotor and plugs to get worn out. Do you know the mileage when those were replaced in '04? If your looking to save a few bucks, try new plugs first and see if it improves. The carbon buildup is probably due to more oil being burned in those cylinders than the others.

[AresROC]

Update on the progress so far:

• Cleaned
  • Throttle body
  • air Control valve
  • EGR Valve
  • EGR Valve vacuum modulator
  • PCV hose
  • Distributor cap
• Checked
  • Plug wire - 800 ohm ~ 1100 ohm, resistance seems high
  • fuel injector ~15 ohm
  • O2 sensor is clean, need to test with analog voltmeter
• Replaced distributor rotor, turns out the old rotor was cracked as well
• Has 1/2 bottle of SeaFoam in crankcase oil

I noticed the throttle body doesn't have a gasket , so I just put it back the way it was.

To do list:
1. check O2 sensor volt during operation
2. check exhaust manifold for cracks. Seems there are smoke coming out of it
3. SeaFoam into intake manifold while running
4. Run a tank fuel with SeaFoam
5. Change oil to 20-50w
6. Check for vacuum leaks?

What do you guys think? ?

[AresROC]

Had smog today, the HC number improved by 100, but not enough to pass . Legal limit is 220 hydrocarbon here, and I got 420...

I put new NGK Platinum spark plugs in, new 20-40w oil, and STP Oil Treatment right before the smog test.

What's interesting is that when I pulled the old plugs, cylinder 1's plug is a little black, so I guess that could mean it's rich. The 2,3, & 4's are light brown, which seems OK. I wonder if cylinder 1 is really my only problem, and how to find out what's wrong.

After seafoaming the car, slick 50, etc, the car runs a lot smoother now! Much quieter too without too much vibrations! If I can only get it to pass smog...

[AresROC]

Update - Smog 3, failed...
Scoring: DMV - 3, Paseo - 0


SMOG# Idle Speed HC (Legal: <= 220 PPM) - Service(s) performed before test
-----+----------------------------------+---------------------------------
1.....517 - Removed EGR carbon clog, checked air filter & throttle body
2.....428 - SeaFoam x2, clean throttle body, 20w50 oil, STP oil treatment, new Rotor/NGK Spark Plugs
3.....294 - new Bosch Oxygen sensor, exhaust leak fix, STP oil treatment, tank of Chevron premium gas
4.....??? - new ECT

• Symptoms
  • High hydrocarbon at idle
  • Lopping idle (jumps around 750 rpm constantly after engine gets hot)
  • Lack of power (common Paseo symptom? )
  • < 30 MPG
• Cleaned
  • Throttle body
  • IAC - Idle Air Control valve
  • EGR Valve
  • EGR Valve vacuum modulator
  • PCV hose
• Checked
  • Plug wire - 800 ohm ~ 1100 ohm
  • fuel injector ~15 ohm
  • Compression, 156~160 psi each cylinder
  • Ignition Timing ~10 degrees BTDC
  • CEL - Short TE1 & E1, no codes - engine idles @ only 700 rpm
  • PCV valve
  • Exhaust manifold-downpipe leak plugged
  • IAT - Intake Air Temp sensor - 1.1 k ohm @ 100f
  • ECT - Engine Coolant Temp sensor - 1.6 k ohm @ 85f
  • Test VF1 & E1 (ECU Lean/Rich voltage indicator) 1.24~1.26 volts normally
  • check for vacuum leak with propane - no leak found
• Replaced
  • Oxygen Sensor
  • Distributor rotor
  • Spark Plugs
  • ECT
• Has 2 bottles of STP Oil Treatment with 20w50 oil.
• To Do:
  • Fuel-Injector (Berryman B12 Chemtool)
  • Valve leakage test
  • replace Air filter
  • Remove IAC & clean - Idle Air Control Valve
• Maybe?
  • Fuel rail pressure
  • MAP - Manifold Absolute Pressure sensor
  • TPS - Throttle Position Sensor
  • EGR - Exhaust Gas Recirculation
  • Idle Up VSV
  • Check vacuum leak
  • Replace?
    • Spark plug wire
    • Distributor cap
    • Fuel filter
    • Ignition coil
    • ECU

Is this way too much work or what! LOL

[96paseo]

If you haven't replaced the cap and spark plugs yet, you should. Have the plug wires been replaced before? You should also Seafoam the intake manifold. You can feed it in with the brake booster hose disconnected. Cut the bottom of a small gatorade bottle and put the seafoam in it. Its much easier than trying to feed it out of the can. Replace your spark plugs after you seafoam it.

[WilliamRobert]

I know that I keep saying this, but have you tried cleaning the injectors? Most shops offer this service (around $50). If the injector is dirty, the fuel may just drip out of the injector instead of a nice spray,if this happens the fuel won't be atomized correctly. Just think of what your spark plugs look like after a few years of service. The injector tips look like that too, just we never think of them. See it all the time on the diesels and gassers at work. An injector service using a pressurized can of concentrated cleaner that hooks right up to your fuel rail is the best way to clean your injectors.
Good job so far, changing the cap and wires like 96 said is something that I also recommend. Improper fuel rail pressures can also cause poor engine performance, something else to think about.
Keep the updates coming, it's kind of nice to see people that like to learn and do the work themselves instead of just bitching and hating.

BillyBob

[96paseo]

+1 on the injector service. For the low price of the service, its very much worth it.

[AresROC]

Thanks! I will add them to the list and keep it updated!

I will also be doing the VF1 & E1 voltage test to determine if I am running rich or not, saves $$$ going to the smogers...