ideling poorly since dual exhaust conversion

[fgross2006]

Since the dual exhaust conversion was finished my car runs badly. The idles jumps from racing to stalling.

I ran a scan and got various codes

in KOEO I got code 31 EGR valve control sensor fault or EVP system below minimum voltage. Not sure which one applies
in KOER I got code 33EGR valve not opening properly
and I also got code 44 Thermactor air system fault

None of these codes were present prior and the car ran and idled fine before the upgrade.

I checked all the vacuum lines and they are all intact. We did remove the exhaust flapper valve which had a vacuum line to it but Im not sure where that line ran from originally.

I have reset the timing and reset the curb idle but its always misleading. It goes from idling perfect to racing to stalling. The dashpot is definitely getting vacuum. What should I looking for in this scenario?

[82GTforME]

I checked all the vacuum lines and they are all intact. We did remove the exhaust flapper valve which had a vacuum line to it but Im not sure where that line ran from originally.

I have reset the timing and reset the curb idle but its always misleading. It goes from idling perfect to racing to stalling. The dashpot is definitely getting vacuum. What should I looking for in this scenario?

I have been having similar issues with my 82 although I haven't had the opportunity to look into it too deeply. In my case I am suspecting a vacuum leak that either gets worse or better depending on the temperature in and around the engine. There may be a leak elsewhere you didn't notice; cracked hose somewhere??

Good luck with the diagnosis. Isn't this fun?

[grabbergreen84]

Did you plug the line to the flapper valve. Could be a vacuum leak.

[fgross2006]

Did you plug the line to the flapper valve. Could be a vacuum leak.

Im taking the car back to my mechanic. I dont know what he did with or to the flapper valve line.

[83gtstang]

Did you keep the catalytic converters on your new system?

[burntorange84]

If you have the vacuum diagram for the CFI system it's a quick look under the air cleaner. On the carb 4V system, the EGR and flapper system run on the same thermal vacuum switch (TVS). That flapper line has to be plugged, otherwise when cold you'll have a vacuum leak. The TVS should shut off the flapper when it gets warm.

-j

[fgross2006]

Did you keep the catalytic converters on your new system?

I pulled the one cat my car had last year. So now Im running dual with no cats.

[83gtstang]

Not sure if this is true, I hope someone can confirm. I've heard that the oxygen sensors don't get hot enough without the back pressure and send false readings.

[fgross2006]

If you have the vacuum diagram for the CFI system it's a quick look under the air cleaner. On the carb 4V system, the EGR and flapper system run on the same thermal vacuum switch (TVS). That flapper line has to be plugged, otherwise when cold you'll have a vacuum leak. The TVS should shut off the flapper when it gets warm.

-j

I dont see anyplace on the air cleaner wheres theres an open line or a plugged one.

I cant find a vacuum diagram that actually shows the routing of the line to the flapper valve. Anybody have a diagram or actual photo of the thing still connected to its vacuum source?

[fgross2006]

Not sure if this is true, I hope someone can confirm. I've heard that the oxygen sensors don't get hot enough without the back pressure and send false readings.

The one problem Im not having is a lean or rich condition so I assume my O2 is functioning correct.

I need to locate the vacuum source that fed the flapper because I cant find an open line or a capped one anywhere near the location the flapper was in prior. If I can find the source I can trace it down the line.

[fgross2006]

I did find the hard plastic tube that is supposed to go to the charcoal canister unplugged. That probably accounts for the EVP code I pulled. The car smoothed out just a bit but still has a stutter in its idle. Im still thinking the vacuum line to the flapper wasnt capped off or not capped in the correct place.

[grabbergreen84]

Computer might still have some learning to do, with the new exhaust, too.

[xctasy]

never had the same matters with his cheap longtube headers.
and single to his LX CFi 5.0 LTD with an 89 roller cam engine with E7 heads.


http://vb.foureyedpride.com/showthre...96#post1753296


Firsly, that's how the CFi sounds cammed up with a E7's and what not. Hard and exceptionally lumpy in comparison.

https://www.youtube.com/watch?v=-tu_dB1Q7Og, right after the swap. If you do a MP3 for the idle frequency, it does have what sounds like a surge, but is actually reversion at idle. It is quite a different note to the high restiction, high velocity stock system.


Secondly, the is a Keep Alive Memory (KAM) and block learning Adaptive Control stratergy (blACs)...its limited, but it has one. It checks all the inputs from the sensors and sets the outputs based on all the parameters that include, adaptive strategy learned, actual sensors readings.It won't fix things untill warmed up.

It relearns over a period. Its typical of Nissan, early CalPacs and EECIV's. Your AC system may be limited and brain dead as far as the EECIV system is concerned (its algorithims were actually updated from the EECIII based system according to the guy I discussed this with). Its functionality is limited because Air pump and EGR oppertation impinges on the storage process but according to ColdwaterHotrod on teamshelby.com, it works like this:-

It uses the last operative value it stored while in Closed Loop. Since the KAM has power to it even when the ignition key is turned off, the blACs table retains it's information. The only way to clear the blACs table is by battery disconnection. Do that and you're back to working with a clean slate and the whole process starts over again. There are limits to how much the blACs can change the calibrations. The blACs table has a range of roughly 25%. CFi isn't as smart as the later EECIV systems, your CFi was the first EECIV before Port EFI, so Ford were still rapidly learning.


Best thing is to fix all the other lines and leaks, and just drive it. The guys who redid the 165 hp EECIV were seriously smart, and there is enough adjustability to cover the idle. The car will always sound bitchy now...enjoy it!


You WILL love it. To miss 30 to 45 hp off the table on the 1984 and 1985 4-bbl m-codes was just intake, exhaust and cam. The 2-bbl intake may have restrictions, but the speed desnity tables of the EECIV, the reduced backpressure, and the huge amount ofvitality from a light and responsive little 5 liter V8...YOU'LL GET THERE!

[fgross2006]

I picked it up today and its still the same. the idle drops to a stall when I come to a full stop. It idles low when in park.

I have set and rest curb idle 3 times. this is not the problem.

I still have codes
KOEO - 31EVP circuit below minimum voltage
KOER - 31, 22 Map out of range, 46 thermactor air is not bypassed, 33 EGR valve not opening properly

I am certain vacuum and possible electrical connections were messed up during the tear down and re install.

A visual inspection and everything looks like it did before the dual conversion. Im left with no choice but to inspect each and every vacuum line one by one and each solenoid to verify whats not getting vacuum or voltage.

I expected the car to idle different after the dual exhaust conversion but this is a definite malfunction. I know from experience that when theres codes, this car runs like crap. when I pull no codes the cars always ran like a dream.

[grabbergreen84]

This:

Im left with no choice but to inspect each and every vacuum line one by one and each solenoid to verify whats not getting vacuum or voltage.

Inspect the vacuum side of it all first.

The "plumbing diagram" is on your V.E.C.I. sticker which should be on the bottom of your hood. And the diagrams I've looked at were good about locating and illustrating the various valves and actuators, so that they can be found and identified.

I suspect a vacuum line. If there are any of those thin smooth vinyl vacuum lines in there, suspect and inspect them. (The lines to the heated-air valves on your air cleaner snorkels should be what I'm talking about.) They like to become brittle, and then break and leak.

Verify that it's all routed correctly, and free of leaks, and if that doesn't do the trick, then start looking at electrical connections (and their associated wiring) which were affected during the work.

[fgross2006]

This:


Inspect the vacuum side of it all first.

The "plumbing diagram" is on your V.E.C.I. sticker which should be on the bottom of your hood. And the diagrams I've looked at were good about locating and illustrating the various valves and actuators, so that they can be found and identified.

I suspect a vacuum line. If there are any of those thin smooth vinyl vacuum lines in there, suspect and inspect them. (The lines to the heated-air valves on your air cleaner snorkels should be what I'm talking about.) They like to become brittle, and then break and leak.

Verify that it's all routed correctly, and free of leaks, and if that doesn't do the trick, then start looking at electrical connections (and their associated wiring) which were affected during the work.

I found the vac between the ported vacuum switch and the HCV was not connected. I replaced the vac tube but I don't think that's the issue with the EGR and thermatic air codes I'm pulling.

[JACook]

The flapper valve runs off manifold vacuum, through the ported vacuum switch. If this line is open
down at the flapper valve end, that is a pretty decent vacuum leak.

The KOER codes are more troubling, but perhaps the engine was not fully up to operating temperature,
and running in closed loop?

[fgross2006]

The flapper valve runs off manifold vacuum, through the ported vacuum switch. If this line is open
down at the flapper valve end, that is a pretty decent vacuum leak.

The KOER codes are more troubling, but perhaps the engine was not fully up to operating temperature,
and running in closed loop?

I made sure the car was at full operating temp when I ran the test. But today I spend most of the day checking everything and I did finally get the running as well as it was before the upgrade. Here's what I found and did;

I removed the plugged vac line off the ported vac switch and replaced it and reconnected to the HCV line. I did also find the other end of the HCV line is open since the flapper is no longer on the car. Should I plug it, leave it open or maybe get a generic one way flow valve to connect to it?

I replaced the vac lines to the dashpot and choke pulloff diaphragm. They were replaced last year but I felt like they stretched out so I put smaller vac line in its place.

I found the electric choke unplugged. I plugged it back in.

I tested each solenoid with the car off by jumpering them to the battery. I verified the EGR, Thermatic air and dashpot solenoids all respond to voltage. Then I ran the car, removed the hose clamps to the TAB and verified there is air flowing with vacuum applied. Then I pulled the vacuum line to the TAB and verified it dumps air out the vent and doesn't flow through with no vacuum present.

I repeated the same test on the TAD and I discovered that air was going upstream to the heads with or without vacuum. Strange since that's NOS Motorcraft TAD but it was definitely not functioning correctly. Luckily I saved the original TAD. I tested both outside the car with a vacuum pump and found the NOS part only flows to the upstream valve even when vacuum is applied and it sounds like the flap inside does move. The old part seems like some air trickles upstream with no vac applied but its like 95% downstream and 5% upstream flow. The car runs great after swapping the TAB. Should I look for a replacement again? Is it normal for some air to escape upstream when the downstream flap is open?

I applied vacuum to the EGR and the car stumbled and stalled so I know the EGR valve is good. I tested vacuum with the car running so I know its functioning correct. At least now it is.

I tried to get my mechanic to look these things over for me but as usual I got the standard excuses "all those cars run that way" and "you should just switch to an Edelbrock and a Holley 4 barrel and get rid of the electronics"

Can I ask if these vacuum lines on my air cleaner are correct?

Attachment 89701Attachment 89702

Here's a vid I took after starting it up. Its now idling at 1000 RPM in park, at 550 rpm in drive. The only code in pulling is 44 that says the Thermatic system failed, Yet the car is running great and I verified the air system is in fact working when the car is running.

Opinions please?

[84StangSVT]

Here's what I found and did;


I tried to get my mechanic to look these things over for me but as usual I got the standard excuses "all those cars run that way" and "you should just switch to an Edelbrock and a Holley 4 barrel and get rid of the electronics"

Sounds like to me that you should find a new mechanic if that is the way he operates. Sounds like what YOU did was fix a bunch of the MECHANICS' screw ups that were not present until he worked on it. Congrats on the troubleshooting success!

[fgross2006]

Sounds like to me that you should find a new mechanic if that is the way he operates. Sounds like what YOU did was fix a bunch of the MECHANICS' screw ups that were not present until he worked on it. Congrats on the troubleshooting success!

So the car ran great yesterday. I haven't driven it today. But does anyone know why Im still pulling a code 44 thermactor system failure even though the car feels and runs great? Also I did verify that the thermator is in fact working while the car is running. I'd like to clear up that last code to be fully happy.

In defense of my mechanic I gotta say that he has done right by me and never ripped me off or sold me service I didn't need. He always does stuff for me much cheaper that the usual shop rate because I'm a regular and I have a lot of vehicles.
One example; After my inability to remedy oil leaks he took my Mustang in, jacked up the engine, dropped the oil pan and changed the oil pan gasket with a one piece steel core Felpro. He also dropped the radiator, pulled the harmonic balancer and re did the front seal since I damaged the last one. While working on this we notice the new and still warrantied power steering pump is leaking. he had his guy pull it, I ran it over to auto zone and got a replacement and he put it in. All this for $250. No mechanic would separate an engine from its mounts, jack it up and drop an oil pan for $250, let alone also replace the front seal and power steering pump for the same price.

Also, the dual exhaust conversion cost me $400 labor, I supplied all parts. The local custom muffler shop wanted $700 labor just to install the pipes and mufflers, not including removing one fuel pump, moving the fuel filter and rear brake line. That part of the job American Muffler wanted done before bringing the car to them.

Yes I have had some frustration with his disinterest to troubleshoot electronic and driveability issues but that stuff is time consuming and if I insist that they go over everything I will no doubt get a bill for it, and since I have learned more about this car's nuances than they understand it isn't a bad tradeoff.

Anyway, I still have a code 44. Any suggestions to correct it?

[grabbergreen84]

Make sure the diverter, and its solenoid, are functioning properly.

I've seen my car throw a 94 or 44, when I knew that it was an Air/Fuel mixture issue, and the emissions stuff was functioning properly.

[fgross2006]

Make sure the diverter, and its solenoid, are functioning properly.

I've seen my car throw a 94 or 44, when I knew that it was an Air/Fuel mixture issue, and the emissions stuff was functioning properly.

I check the EGR, Thermactor and Dashpot solenoids, they all are working as far as I can see. The TAD and TAB are both working too .

[JACook]

44 says the O2 sensor is never seeing upstream air (not going lean), when the diverter is commanded
to go upstream. In simple terms, that means the ECU thinks no air is going into the back of the cylinder
heads.

Either the diverter is never sending the air there, or when it does, the pump is in bypass, or the pump
just isn't pumping enough air to influence the O2 sensor. Make sure your hoses aren't swapped between
the diverter and bypass valves.

44 has nothing at all to do with EGR. Entirely different system.

[fgross2006]

44 says the O2 sensor is never seeing upstream air (not going lean), when the diverter is commanded
to go upstream. In simple terms, that means the ECU thinks no air is going into the back of the cylinder
heads.

Either the diverter is never sending the air there, or when it does, the pump is in bypass, or the pump
just isn't pumping enough air to influence the O2 sensor. Make sure your hoses aren't swapped between
the diverter and bypass valves.

44 has nothing at all to do with EGR. Entirely different system.

I drive the car on a long run today about 25 miles. One the way out to my destination it was idling too high. 1000 RPM in drive with AC on.

I assumed I'd need to adjust the curb idle when I got home but about the time I got back to my town it started stumbling. When I got home I ran a scan and came up with
KOEO - 31 EVP below minimum voltage
CM - 31 and 18
KOER - 41 O2 sensor voltage low running lean, 31, 33 EGR valve not opening properly

Im stumped. I checked every item and found the TAD and TAB to be working while the car is on and the EGR as well. I don't know what else to do.

[grabbergreen84]

18 is SPOUT. I think you might have a bad connection or wire which got jarred and made worse, when the exhaust or timing cover work was done.