thermactor system

[svtdrop]

i am having a idle issue with my car, idle seems to surge alot, so far ive replaced, iac valve, tps, o2 sensors, iat sensor, fuel pressure regulator, now when i hook the scanner up, i get code 334. then when i run a scan on idle, i got 2 codes, tryed to retreive but scanner broke, lol.. it was a 2 thermactor code left and right, i checked the check valves for the smog pump and are ok, checked vacuum lines and are ok.

has this happened to anybody? any help would be appreciated...

 

[HISSIN50]

Do you have a functional EGR system?

 

[svtdrop]

how can i tell if its functioning?

 

[sl03gt]

Kind of having the same problem except my smog is deleted. Only pulling 13lbs of vacuum. Checked ignition, sprayed intake with carb cleaner, vacuuum lines, leak down, compression, and cleaned the injectors and still have the same problem. It passed emmisions with no problem. I get the same code when koeo test. The only thing I can think of is a bad injector. Maybe someone else will chime in and help us both.

 

[Chythar]

What Hissin means is, have you removed the smog equipment?

 

[svtdrop]

i have the smog pump on, i also did replace the egr valve...... my car still passed smog with this idle issue but kept turning off on the dyno...lol

 

[HISSIN50]

Chythar was right-on.

FWIW, the Smog (A.I.R.) and EGR can be considered unrelated (there is a tiny relationship but it's nothing that pertains to this thread).

What I would do is to put a test light across each smog solenoid (AIR 1 and AIR 2) and run KOER codes. The test light will illuminate as each solenoid is tested. If that passes, disconnect each solenoid's electrical connector and manually actuate them and see if the vac passageway opens.

You can do the same with the EGR solenoid.

Also be sure that the vacuum lines to and from all of these solenoids are in good shape. The lines are plastic and break all the time. A break in a feed line can lead to low vacuum readings.

Also check your CANP line - if it degraded (fuel causes it to break down), this can cause a vac leak.

Good luck.

 

[svtdrop]

Chythar was right-on.

FWIW, the Smog (A.I.R.) and EGR can be considered unrelated (there is a tiny relationship but it's nothing that pertains to this thread).

What I would do is to put a test light across each smog solenoid (AIR 1 and AIR 2) and run KOER codes. The test light will illuminate as each solenoid is tested. If that passes, disconnect each solenoid's electrical connector and manually actuate them and see if the vac passageway opens.

You can do the same with the EGR solenoid.

Also be sure that the vacuum lines to and from all of these solenoids are in good shape. The lines are plastic and break all the time. A break in a feed line can lead to low vacuum readings.

Also check your CANP line - if it degraded (fuel causes it to break down), this can cause a vac leak.

Good luck.

i did the KOER scan and i got 2 dtc;s
311 = thermactor air system inoperative(right)
314 = thermactor air system inoperative(left)

where are the smog solenoid's located at?
also what is the CANP line and where is that located?

 

[Chythar]

The solenoids are in the passenger fender - you'll need to remove the wheel and splash guard to get at them. The CANP line leads from the intake to a black cylinder (which has a electrical connector), then leads in to the passenger fender to a charcoal canister. I believe CANP stands for "Canister Purge Solenoid" (the black cylinder). Rubber vacuum hoses crack with age and leak. If you're going to pull the passenger splash guard I recommend replacing all the rubber hoses at the same time. You can use standard rubber hose in bulk found at most auto parts stores.

 

[svtdrop]

i removed the splash guard and i got access to the canister and i did find a hose that was leaking. fixed the hose, but the idle is still surging. i wanted to scan the ecu but my scanner broke........ Also there is a line from the canister that goes to engine area and is open, is that for vapor?

 

[HISSIN50]

i removed the splash guard and i got access to the canister and i did find a hose that was leaking. fixed the hose, but the idle is still surging. i wanted to scan the ecu but my scanner broke........ Also there is a line from the canister that goes to engine area and is open, is that for vapor?

It sounds like someone opened the gas tank ventillation system.

Be sure the port [on the intake where the purge line used to go] is sealed. If not, that's your vac leak. I would restore the system (so you dont dump raw fuel vapor into the atmosphere. If you park near a pilot light, this could be dangerous [gas fumes and affects on beings' health aside]).


If the open line is between the cannister and purge solenoid (the black cylinder on the passenger firewall area), there will be an intermittant vac leak. If the open is between the purge solenoid and the intake, the leak will be constant. Repair it.

This issue is what we were talking about with the CANP lines. The fuel degrades the rubber and you get leaks.

Good luck.

 

[svtdrop]

i did repair the lines, but there still a surging idle! do you think the solenoid can cause that?

i was reading the manual and it said to test the solenoid, apply 9-14 DC volts to solenoid terminals and apply 53 kPa to manifold side nipple,


im going to try that next, also, not to sure if last owner maybe connected the lines backwards, im going to check all of this today?

 

[HISSIN50]

The solenoid should not cause the surging idle. All it does is empty the vapors in the charcoal cannister under certain light throttle conditions.


A vac leak or other unrelated issue is probably causing the surging.

 

[Chythar]

It sounds like someone opened the gas tank ventillation system.

Hissin, I think he means the dedicated line from the canister that runs to the passenger frame rail near the front and is vented to open air. It's been there on all 3 Mustangs I've worked on and certainly looks stock.

svtdrop, that should be the only line that's open to air like that. Hissin is dead on on the hose fittings - if they're loose at all, you likely have a vacuum leak. If the hose isn't snug and kinda hard to remove then it's likely loose and should be replaced.

The vacuum lines leading from the solenoids are thin plastic hoses, and are easily split. I've also noticed leakage from the hose juncture in the engine compartment as well. there are four color-coded lines - one provides vacuum from the manifold; one leads to the EGR, and the other two lead to the smog equipment under the air intake hose.

 

[HISSIN50]

Hissin, I think he means the dedicated line from the canister that runs to the passenger frame rail near the front and is vented to open air. It's been there on all 3 Mustangs I've worked on and certainly looks stock.

When he said that the line went to the engine compartment, I dismissed the fresh-air vent line. I bet you might be correct in which line he was talking about though. If so, mine is like yours have been - it's tacked to the frame rail.

Good catch.

 

[mo_dingo]

have your checked how much vacuum you are pulling?

 

[svtdrop]

how to i check to see how much vacuum im pulling....

 

[mo_dingo]

how to i check to see how much vacuum im pulling....

You need a vacuum gauge. I got mine at sears. You simply hook it up to a vacuum source (vac tree on upper manifold is good).

You want a steady reading. So note if it's stable, and also the number in inches and let us know.

Some people spray carb cleaner around the vacuum lines, trying to find leaks...

Have you cleaned your MAF ever?
Scott

 

[svtdrop]

where is the vacuum supposed to be at? im not sure if im reading it right but it was .5

 

[HISSIN50]

You should see about 20" hg at idle.