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Smog pump bypass?

Ton van der Sluijs

official Lucas dealer
Goodmorning Greystreak:)
sometimes I think, that my E4 is opgraded already, because all the shifts are short, and one can feel it shifts.
About the overdrive... I do have a very conservative way of driving; OD is always off under 55MPH. What I did mention about interfering in the 3-4 pack is, that sometimes when I drive let's say 40MPH, the engine runs a neat 1500 revs.... That is good but a bit more revs is nicer for the engine... I do have no experience with other tranny's but I've read the troubles with OD's and therefore I switch it off at low speed. I do think personly , that the OD is at the wrong side of the system; it's just behind the TC. That means, all the revs of the engine goes straight in the OD... In my opinion the only way to avoid a burned OD is "Off under 55".
I've did reset the system and she runs better now in idle.. the smell is gone only still some dips; I do suspect a dirty plug or I have to clean the distributorhead in side after two years of service.

Best regards and thanks very much for your input!!!
Ton
 

Fellro

Moderator
Staff member
The location of the OD doesn't affect it's longevity, as the power flow is such that it is not used at all when not in use. The location of the components has more to do with the planetary gears than strength. The planetaries are what give you 1st - 3rd gears, then the overdrive is engaged with the drive or 3rd gear engaged on many systems. Without reading up on the powerflow Ford used, can't validate the same here. Chrysler had the idea to hang an overdrive unit on the back of the old 727 and called it the A518. It was nice in that the overdrive was a standalone, but was it's own nightmare because it was an afterthought. They finally added a lockup clutch a few years later.
 
Apologies for the length of this post...

EEC-IV: Some folks like to call it OBD-I but it was actually the fourth generation engine/emissions control system Ford engineered. Ford employed it in light trucks (1985 EFI-1995). The Thermactor system pushed fresh air into the heads just DOWNstream of the exhaust valves AND/OR into the exhaust pipe just UPstream of the catalytic converter. BOTH ports have a specific function and BOTH are indeed necessary because the EEC-IV computer USES them to control the engine's operational parameters and in so doing, reduce emissions output insofar as the system is capable.

Upstream of the catalytic converter: This port serves to introduce more oxygen into the exhaust stream to enable the OEM catalytic converter to achieve the necessary temperatures to burn-off the crud its supposed to burn off. (Adding fresh air/oxygen to hot exhaust gasses... its like opening a window in a house that was burning. The fire was out... but you just gave it a big deep breath of air). So, unless you have swapped a newer (more efficient) cat into the vehicle, the OEM cat will NOT function without the fresh air from the pump.

Downstream of the exhaust valves: This port serves to keep the HEGO (Heated Exhaust Gas Oxygen) sensor (O2 sensor) from getting a false "rich" reading before the engine fully warms up. The EGR is also closed at this point so ALL of the exhaust is headed down the pipe. This is the ONLY point in time that the Thermactor air is EVER used to "dilute" exhaust gasses. A cold engine needs more fuel and less air however, under normal operating temperatures, the fuel level is greatly reduced and the air level increased. So, until things warm up, the O2 sensor is going to get readings that are way over on the "rich" side of the ratio. Once warmed up, the EEC-IV computer shuts this air injection down so as to get accurate readings during normal operation.

TAB & TAD solenoids: The EEC-IV computer changes the flow of vacuum through the TAB (Thermactor Air Bypass) and TAD (Thermactor Air Diverter) solenoids (most frequently mounted near the ignition coil). These two electronic solenoids are nothing more than vacuum switches. They control the flow of vacuum to the Diverter Valve.

Diverter Valve: (behind the passenger cylinder head on the V8's) Redirects fresh air from the Thermactor Air Injection Pump (smog pump) between the ports in the cylinder heads and the port in the exhaust pipe. The EEC-IV computer controls this flow of air from the smog pump DURING engine operation based on temperature and throttle position.

This system is completely integrated and removing just one or two parts adversely affects engine operation. Even if the EEC-IV computer can compensate for the missing information, the LACK of this information causes the computer to alter the operational parameters of the engine... there is no way around this without rewriting the software in the EEC-IV computer. (And no, performance chips don't do this).

EGR: Exhaust Gas Recirculation is a system that is actually much older than any electronic control system. Early EGR was employed by some auto makers as far back as the late 1960's. This system uses a valve to allow a controlled amount of exhaust back through the intake in an effort to run unburned crud back through the combustion cycle to "try again" so to speak.

So, why does it matter if it isn't there? In older carburated systems, if the EGR was removed, you could simply retune the carburetor to adjust for the missing partial air/partial combustibles coming in through the intake. Simple enough. However, with a system like EEC-IV and other electronic engine control systems, if you just remove that flow of air & combustibles all together, you are taking away something that the computer was programmed to control and calculate. So imagine for a minute, that you suddenly removed a predetermined amount of air and fuel from your engine but you could make no adjustment to compensate for the loss. Well, Ford couldn't have that happen so they programmed the computer with options so it could still keep the engine running... not nearly as well as with the system functioning properly but the vehicle would run well enough to get you home. Since EGR is controlled by vacuum AND electronics the EEC-IV computer can "know" how much exhaust gas is recirculating and make fuel/air mixture adjustments accordingly. However, if the EGR is removed all together, the computer must "guess" and since it cannot control the EGR valve anymore, it spends a LOT of time trying to adjust spark timing and fuel/air mixture to compensate for the loss of exhaust gasses back through the engine. Remember the O2 sensor "knows" when the exhaust gasses are "rich" or "lean" and it snitches about 8 times per second. What you end up with, particularly in a gasoline engine, is a lot of erratic idle issues... is it any wonder?

The problem that we are dealing with here in this thread is that Ford engineered these systems in such a way that IF some part DOES fail, the computer will keep the engine running "well enough" to still drive the vehicle but it will trigger the "Check Engine" light to warn the driver that even though the vehicle still APPEARS to be running properly, there is something amiss. Running this way for extended periods of time WILL eventually cause bigger problems unless its fixed. What folks who arbitrarily remove parts of the system FAIL to accept is the FACT that just because you remove or ignore the Check Engine light (or put tape over it...which is my personal favorite uneducated maneuver) does NOT mean the engine is "running fine" and further it means that whatever the EEC-IV computer is doing to compensate WILL cause other problems that WILL be worse in the long run. Remember the EEC-IV computer controls fuel-air ratio and spark timing along with shift points (E4OD only). Anyone who knows anything about internal combustion engines knows that these settings/adjustments are critical and failure to maintain them results in terrible problems if not immediately, then definitely over extended periods of time. When you are dealing with a vehicle where the ONLY way to be certain that these adjustments are correct is to make certain the on-board computer has ALL of the information it needs, maintaining ALL of the sources of that information becomes as critical as spark timing and fuel/air mixture. These are the FACTS. Argue if you feel you must but they will not change no matter how much you want them to or how much you talk about it.

Thanks for the most detailed understandable explanation i've ever read regarding the EGR and it's interaction with the rest of the emmissions components.
 

Ton van der Sluijs

official Lucas dealer
The location of the OD doesn't affect it's longevity, as the power flow is such that it is not used at all when not in use. The location of the components has more to do with the planetary gears than strength. The planetaries are what give you 1st - 3rd gears, then the overdrive is engaged with the drive or 3rd gear engaged on many systems. Without reading up on the powerflow Ford used, can't validate the same here. Chrysler had the idea to hang an overdrive unit on the back of the old 727 and called it the A518. It was nice in that the overdrive was a standalone, but was it's own nightmare because it was an afterthought. They finally added a lockup clutch a few years later.

Thanks FellrosmilieIagree

Thanks to Blackhat, Greystreak and Buzzgun, I do now fully understand the system!
when I had bought the truck, the running was rough, and I saw the EGR valve bouncing up and down, so, I blinded it off .....and forgot. now I know that de EGR was bouncing, due to a wrong LPG system, the EEC was trying with EGR, ignitiontiming to look for the best solution.. I swapped LPG for LPI but I left the blocked EGR.. right now, the truck runs great!
A strange thing is, that first idle at 750? Never! It did had a rough, weak idle and stalling occured all the time... Now she keeps running at 750!

best regards to all

Ton
 
"If the catalytic converter is the OEM unit, and the Thermactor Air Injection Pump (smog pump) is missing, then the catalytic converter is NOT working. It can't."

With the cat not working, does it hinder anything? Better to remove it or leave it there for looks? It's fairly new, looks better than the truck body itself.
 
Well, that IS the dilemma isn't it. A functioning cat cannot legally be removed. However, since the Thermactor pump is not "functioning" it renders the cat "non-functioning". It won't hurt anything to leave it in place however, since it will not heat to the necessary temperature to work properly, you run the risk of it clogging more readily. This can eventually lead to serious engine issues up to and including burned valves and complete stalling if the substrate breaks down and collapses. Now I don't say this to scare you but merely to inform you that having a non-functioning cat in place (no matter how good it looks) can eventually be a detriment to the engine so keep an eye on it if you leave it in there.
 
Ton,

Glad you got it worked out. I hope this thread helps anyone who may seek the exhaustive (no pun intended) information that has come from it. And please don't let this stall the flow of further information. I agree with you that continued conversation in an open forum will help others as well.

GS92
 

Ton van der Sluijs

official Lucas dealer
Hey guys! Goodmorning from this side!
Yesterday I had to go to Haarlem with the truck.. I took the highway and my truckie is incredible fast now and no dips when accelerating!! she has a smooth ride and the trans shifts later, so the engine revs up higher. what a truck!!

I've bought a nice (is that what you can call a "nick nack?") An Air/fuelratio gauge, with an O2 sensor. I do have a program in my laptop, to interfere in the LPGinjection computer and then one can adjust the perfect mixture. I keep you posted.
best regards Ton
 

Ton van der Sluijs

official Lucas dealer
Goodmorning Greystreak.
They are expensive here as well... They (Gov) do have a mouth full about environment and that LPG is the cleanest... BUT... If everybody uses LPG. Gasoline shall be piled up skyhigh in storagetanks in Rotterdam.. LPG is a leftover from the refiningprocess.. Many years they had to burn it in open sky. That's why they make the roadtax so expensive.... Have you ever thought about buying a kit in Europe?

best regards Ton
 
Questions

Apologies for the length of this post...

EEC-IV: Some folks like to call it OBD-I but it was actually the fourth generation engine/emissions control system Ford engineered. Ford employed it in light trucks (1985 EFI-1995). The Thermactor system pushed fresh air into the heads just DOWNstream of the exhaust valves AND/OR into the exhaust pipe just UPstream of the catalytic converter. BOTH ports have a specific function and BOTH are indeed necessary because the EEC-IV computer USES them to control the engine's operational parameters and in so doing, reduce emissions output insofar as the system is capable.

Upstream of the catalytic converter: This port serves to introduce more oxygen into the exhaust stream to enable the OEM catalytic converter to achieve the necessary temperatures to burn-off the crud its supposed to burn off. (Adding fresh air/oxygen to hot exhaust gasses... its like opening a window in a house that was burning. The fire was out... but you just gave it a big deep breath of air). So, unless you have swapped a newer (more efficient) cat into the vehicle, the OEM cat will NOT function without the fresh air from the pump.

Downstream of the exhaust valves: This port serves to keep the HEGO (Heated Exhaust Gas Oxygen) sensor (O2 sensor) from getting a false "rich" reading before the engine fully warms up. The EGR is also closed at this point so ALL of the exhaust is headed down the pipe. This is the ONLY point in time that the Thermactor air is EVER used to "dilute" exhaust gasses. A cold engine needs more fuel and less air however, under normal operating temperatures, the fuel level is greatly reduced and the air level increased. So, until things warm up, the O2 sensor is going to get readings that are way over on the "rich" side of the ratio. Once warmed up, the EEC-IV computer shuts this air injection down so as to get accurate readings during normal operation.

TAB & TAD solenoids: The EEC-IV computer changes the flow of vacuum through the TAB (Thermactor Air Bypass) and TAD (Thermactor Air Diverter) solenoids (most frequently mounted near the ignition coil). These two electronic solenoids are nothing more than vacuum switches. They control the flow of vacuum to the Diverter Valve.

Diverter Valve: (behind the passenger cylinder head on the V8's) Redirects fresh air from the Thermactor Air Injection Pump (smog pump) between the ports in the cylinder heads and the port in the exhaust pipe. The EEC-IV computer controls this flow of air from the smog pump DURING engine operation based on temperature and throttle position.

This system is completely integrated and removing just one or two parts adversely affects engine operation. Even if the EEC-IV computer can compensate for the missing information, the LACK of this information causes the computer to alter the operational parameters of the engine... there is no way around this without rewriting the software in the EEC-IV computer. (And no, performance chips don't do this).

EGR: Exhaust Gas Recirculation is a system that is actually much older than any electronic control system. Early EGR was employed by some auto makers as far back as the late 1960's. This system uses a valve to allow a controlled amount of exhaust back through the intake in an effort to run unburned crud back through the combustion cycle to "try again" so to speak.

So, why does it matter if it isn't there? In older carburated systems, if the EGR was removed, you could simply retune the carburetor to adjust for the missing partial air/partial combustibles coming in through the intake. Simple enough. However, with a system like EEC-IV and other electronic engine control systems, if you just remove that flow of air & combustibles all together, you are taking away something that the computer was programmed to control and calculate. So imagine for a minute, that you suddenly removed a predetermined amount of air and fuel from your engine but you could make no adjustment to compensate for the loss. Well, Ford couldn't have that happen so they programmed the computer with options so it could still keep the engine running... not nearly as well as with the system functioning properly but the vehicle would run well enough to get you home. Since EGR is controlled by vacuum AND electronics the EEC-IV computer can "know" how much exhaust gas is recirculating and make fuel/air mixture adjustments accordingly. However, if the EGR is removed all together, the computer must "guess" and since it cannot control the EGR valve anymore, it spends a LOT of time trying to adjust spark timing and fuel/air mixture to compensate for the loss of exhaust gasses back through the engine. Remember the O2 sensor "knows" when the exhaust gasses are "rich" or "lean" and it snitches about 8 times per second. What you end up with, particularly in a gasoline engine, is a lot of erratic idle issues... is it any wonder?

The problem that we are dealing with here in this thread is that Ford engineered these systems in such a way that IF some part DOES fail, the computer will keep the engine running "well enough" to still drive the vehicle but it will trigger the "Check Engine" light to warn the driver that even though the vehicle still APPEARS to be running properly, there is something amiss. Running this way for extended periods of time WILL eventually cause bigger problems unless its fixed. What folks who arbitrarily remove parts of the system FAIL to accept is the FACT that just because you remove or ignore the Check Engine light (or put tape over it...which is my personal favorite uneducated maneuver) does NOT mean the engine is "running fine" and further it means that whatever the EEC-IV computer is doing to compensate WILL cause other problems that WILL be worse in the long run. Remember the EEC-IV computer controls fuel-air ratio and spark timing along with shift points (E4OD only). Anyone who knows anything about internal combustion engines knows that these settings/adjustments are critical and failure to maintain them results in terrible problems if not immediately, then definitely over extended periods of time. When you are dealing with a vehicle where the ONLY way to be certain that these adjustments are correct is to make certain the on-board computer has ALL of the information it needs, maintaining ALL of the sources of that information becomes as critical as spark timing and fuel/air mixture. These are the FACTS. Argue if you feel you must but they will not change no matter how much you want them to or how much you talk about it.


Sorry to bring up an old thread, but I just want to clear up a few questions I have regarding removing stuff without an EEC programming adjustment.

1) The only negative side to removing the smog pump is that the computer might run a little lean until its at operating temperature where the secondary air system diverts the flow from the back of the heads down to the cat?

I have a modern 3-way catalytic converter installed, so I assume the air the downstream the o2 sensor at operating temperature is irrelevant. Basically just let it warm up without putting a load on it or turning a high RPM will avoid timing advancement and any unsafe conditions are essentially avoided. Driving at operating temperature should be perfectly safe?


2) Based on the information here, leaving the ERG is the best thing to do unless you are modifying the programming?
 
Well you see the problem with the entire idea here is in your first statement...
...I just want to clear up a few questions I have regarding removing stuff without an EEC programming adjustment.

You cannot alter the EEC-IV programming. End of story. There is no "performance chip" or memory re-flash that will alter the software to allow the removal the Thermactor system or any of its components because that kind of modification is not legal. Aftermarket modifications whether they are software or hardware cannot bypass (or necessitate the bypass of) the emissions systems that make the vehicle compliant for the model year it was produced. So, unless you are writing illegal EEC software code, there is no way to arbitrarily remove components from the system without the EEC-IV computer compensating for it. Furthermore, every compensation the computer makes will eventually have an adverse effect on engine operation.

This thread actually served to show a handful of people (initially) that the system actually operates more efficiently when all of the components are functioning properly. Hopefully it will provide the information to others as more read it.
 
Pushing the "smog Nazis" aside if your catalytic converter is old and empty it
won't do a thing positive or negative (from anybody's perspective) to delete
the smog pump. All it takes is some plugs and a shorter belt on a serpentine
belt system on a 5.8. From what I've read tho, the 5.0's serpentine system
isn't so easy, it needs a pulley or something? :/

The holes in the back of the 5.8's heads are ordinary 5/8-11 bolt threads.

-----------------------

While I was at it I fiNgured out what belt it takes to also bypass the power
steering pump after having one leak to beat hell on a trip. :) Last time I had
trouble like that was on my '75 pickup and just removed the belt. :) So now
I carry a special belt just so the power steering can be deleted on my '91
Bronco too. :)

If the A/C bearing goes out it's a 5106 and common, just stop and change it
out. xD Same goes for the idler bearing it's even more common it's a 6203.

Alvin in AZ
 
Alas, your information is only half the equation. The smog pump also pushes fresh air into the heads prior to engine warm up keeping the inherently rich condition created when a cold engine requires more fuel in the mix. Without this air injection, the O2 sensor "tells the computer to lean out the fuel mixture prior to entering closed loop which causes a lean condition that damages spark plugs and super-heats cylinder walls ultimately causing premature plug failure and premature/excessive ring damage. But then, we covered that in the course of this thread.
 
the last post in this thread was on 4/2013. And yet I was foolish enough to buy my 16 year old a Bronco last year, a 95, and have been dealing with my mistake ever since... I have always loved, and was fascinated by, Broncos when I was a kid (I'm 46 now), and still do love them, but this rig (in particular) was NOT worth the trouble, time, money, etc.

anyhow, onto my post:

Greystreak - you, and Steve83, are both two of the most informed Ford fanatics I know of on the internet. You both know your sh** inside and out about how these engines work, and the differences betwixt them. my sincere respect to you both in that regards.

it's amusing, fascinating, and dare I say weird, all the flip-flap that goes on, in these forums, about emissions this and that, and should I delete it or should I not, and the govt and big oil are Nazis and Evil and on and on. I'm a pretty technical person myself, and understand a little about chemistry, NOx, CO, CO2, the burning of hydrocarbons, how a cat works, etc. I get it that emissions stuff helps your engine to a) reduce knock, b) reduce pre-detonation, c) raise or lower intake/exhaust temperatures, d) reduce harmful emissions, e) adjust your engine while running to get optimal performance. That, I all agree with, sure. But let's consider those people who don't give a poop about emissions and harming the environment... I believe that for anything you gain in life, there is usually a sacrifice of some kind. It seems to me, and I think a lot of suspicious people think the same way, that in order to gain less harmful emissions, *something* must be being done to the engine that in some way ruins or slackens optimal performance. I don't think anybody has quite phrased it that way in this particular thread, but that's what I'm guessing is most wannabe gear-heads opinion: "I have better emissions, it MUST be at the expense of my MPG or output torque". So many posts are complaining about re-introducing "dirty exhaust" back into the intake manifold and re-burning it. Even though you explained that it helps control the burn rate, and reduces NOx, I bet most people think "it makes my engine run crappy". There have been SO MANY posts of people who state their engines run BETTER after removing EGR and/or 2ndary air, and so many posts by yourself (or others) telling these (idiots) they don't know a THING about how this chemistry works, it made me wonder... WHO has ACTUALLY *DONE* a live test of what the injectors are doing, in a city environment, or on the highway, with and without the EGR, or the 2ndard air running? screw the dyno-test, all I want to know, technically, emissions aside, is: Is the engine working harder or easier, with the EGR and air systems on or off? who is really "right" about if these systems help or hamper normal driving? Again, this is assuming you don't give a poop if this planet gets polluted and eventually causes the surviving humans to look like lumpy cancer ridden zombies. I personally DO care about the environment and want to keep my smog stuff ON, but as a scientist (of sorts), I'd love to know the REAL story about how this equipment affects actual heat-pump combustion engine performance.

For my personal problem, I'm trying to put a 96 351W engine into my 95 engine bay. the old engine had the secondary air system, and has the air crossover tube coming up off the exhaust. The 96 engine does NOT have the smog pump, and expects the newer-style cats that don't need the extra air from the smog pump. But likewise, the heads don't have the air ports in the back (or the front!) to accept the air crossover tube, either. And no, they're not plugged, the ports just don't exist. Thus, I am/was/is strongly considering just letting the air crossover tube DANGLE in the back behind the engine, and let the engine run lean while starting up. the air will be poured out happily by the TAD and TAB solenoids while starting up, the EEC will see it's making no change, will run the engine lean until it warms up. Meanwhile the smog pump will still be there (because I'm stealing it from the 95 engine) and it will send fresh air to the cat. Does this sound 'really bad" to you? To the point where I should pull off my heads and take in the old ones (the ones with the ports) to the machine shop and have them redone and put THEM back on? it will cost me another $250 to get the heads done, $80 for the head gaskets, another $25 for exhaust gaskets, $75 for the crossover tube (includes shipping), and of course the labor. The engine is currently sitting OUT of the car with nothing on it but the bolted down heads, exhaust manifolds, and intake manifold. it'd be easier for me to correct it NOW rather than later, if it will end up being a big deal.

My opinion seems to be that the engine running lean during startup = cylinder heats up faster = takes less time to warm up = no big deal. is this impression really that wrong?

Hope to see a reply from YOU, Graystreak.

thanks
 
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