Thermactor question, Not egr question.

ZanderH · Dec 13, 2009

I don't know any other way to do it than this so sorry about the extra thread. I started the thread egr question but I was mistaken.

The system I was talking about was the thermactor system. Anyway, it's an 84 Bronco 2 xlt 4x4 2.8l. The hose that goes to the nipple from the exhaust header has been cut off and plugged. I don't know why. It was like that when I bought the B2 Friday and didn't see it till yesterday. So with that being cut off and plugged the nipple from the exhaust manifold is shooting fumes into the engine bay and leaking into the cab. My question is does anyone know of any reason(s) that that tube would be cut and plugged? Maybe the check valve/air bypass valve was bad? I wonder if they even sell those anymore.

I need to get this thing ready for inspection asap so I can stop waking my wife and kids up to take me to work. I live in virginia. We don't get a tail pipe emissions, but they do perform a visual inspection so I'm pretty sure I'm going to have to have it hooked up properly to pass otherwise I would just cap the nipple somehow.

Eric Kropp · Dec 13, 2009

I just put a reply on the first thread you posted...did not see the "please delete" note until after I was done typing and posting. If you don't get it before it is deleted I will type it again.

Eric<><

Eric Kropp · Dec 13, 2009

There are two check valves on the thermactor system, at least on mine there is. One that comes from behind the engine. This one ties the two manifolds together at the back and come out from behind on the right side of the engine. The other one comes up from the cat/converter. If either of the check valves at the end of the tubes are shot it will dump exhaust gas into the engine compartment. Chances are, since this is what you described, the check valve is shot and the hot exhaust gas probably melted the hose that hooks on to the check valve. I have had this happen to me. The one that hooks to the manifold may be kind of a stinker to get to especially if the bolts(one on each manifold)are rusted or heat frozen. That part is only sold as a complete piece, piping and all. The one to the cat can be had with out the pipe. I purchased them on-line. I live in California and have to have all the smog stuff looking and working right.

dangerranger83 · Dec 13, 2009

People dont want the emission stuff on theres so they disable them and take them off.

ZanderH · Dec 13, 2009

I guess you both could be right. The check valve might have gone and tube may have melted so they just cut it off and plugged it instead of fixing it.

Eric Kropp · Dec 13, 2009

It would seem if some one was removing it for "I don't want smog" reasons, they probably would have completed the job by removing every thing. If you need, I could probably send you some pictures of what it should look like. I would probably need an email address as I am not computer savy enough to put a picture on this forum

Eric

enginepaul · Dec 14, 2009

You would leave the pipe to the heads in place, even if you disabled the system, to prevent leaks; but the pipe (tube) should be plugged. The check valve can be purchased as a clamp-on replacement.

One of those valves dumps excess air to the atmosphere (under the hood) the other directs it to the cat converter.

As for your visual inspection, try the youngest guy you can find - he may be born after your B II was made and have no idea what he is looking at.

kimcrwbr1 · Dec 14, 2009

thermactor

Hi the check valves can be purchased at most any part store and if the air pump and vacuum lines are not working you can just hook them as if they were. there should be two controls the bottom one is the bypass valve and the upper one is the thermactor on mine the upper port goes to the manifold crossover and the one out the back goes down to to the catalitic converter. my thermactor was completly burnt out internally from a bad check valve. If the EGR is still working I suggest getting the air system working with it there should be a vacuum diagram under your hood it made my ranger run better something to do with the oxy sensor and comp stuff. When I got my 83 ranger It was almost overwhelming looking at it but glad I went through it for the price of gas alone. just take your time the parts aren`t cheap fix the obvious first yea fix the co leak dont want brain damage. I bought a code reader for the EEC-IV on ebay and most of the pollution crap. I am not sure if the california emmisions are any different on your truck but if you need a diagram and advise email me at kimcrwbr1@aol.com I just went through it all and would be glad to help better diong it yourself than paying $110 an hour for someone to change a couple of hoses. Kim

ZanderH · Dec 16, 2009

Well, I tested the valves yesterday. The diverter valve (check valve) checked out good, but the air bypass valve didn't. Getting vac on both lines too. Advance didn't have one, but I hooked it all back up the way it's supposed to be anyway to at least relieve myself of the exhaust in the cab. I'll have to hunt around for a new bypass valve. Hopefully when I go to pick n pull friday that ranger I saw won't be too stripped out. With any luck that one will still be there. Along with the other parts I hope to pull off it. Thanks for the help!

ZanderH · Dec 18, 2009

Well, I found out why the thermactor system was not hooked up. After putting it back together, now after about 20-30 minutes of driving, it stumbles badly. It idles, but as soon as I put a load on it, it stumbles. As soon as I let off the gas it idles again. Gonna have to do some research on the thermactor system and see what I can find.

enginepaul · Dec 19, 2009

Sorry to ask so late in the game - BUT are you allowed to do a DuraSpark conversion?
If you have a stock, computer controlled engine; all components must work for it to run properly. If you need the original smog in your state, then start by pulling codes/
I need the original system and I have it running fine after lots of work.
Ask someone at the test sattion or elsewhere if the DuraSpark is OK because that is the cheapest and easiest way to go.

ZanderH · Dec 20, 2009

After doing some research on this PITA system I've found the check valves are gone. As far as duraspark I don't know. I'll have to ask around, but I have been reading around on here about it and saw that finding parts to do that is getting hard. I'm tempted to just throw antique tags on it and call it good till I get it running right.

enginepaul · Dec 20, 2009

Killing time here and found this on Virginia's State web:
"Gasoline powered passenger or property carrying vehicles with a model year that is more than 25 years old before January 1 of the current calendar year.

EXAMPLE: Vehicles with a model year of 1984 are exempt from emissions on or after January 1, 2009; vehicles with a model year of 1985 will be exempt from emissions on or after January 1, 2010.

Vehicles 25 years old or older qualify as antique motor vehicles but are not required to display antique license plates to qualify for the emissions exemption. Although exempt from the emissions inspection, the $2 emissions fee is required when renewing these registrations."

Soooo. . . . my sugestion would be duraSpark and that usually should be cheaper than getting a stock system back in order and won't take any special tools or test equipment.

ZanderH · Dec 20, 2009

Sweet! Thank you very much. I've been planning on looking on Va's site to see what I could find out about it but have been busy working on the B2 and remodeling the house. Those two things clash badly by the way. Especially since the remodeling is my wife's idea. Any married man knows how that goes.
So the thermactor system, being part of the emissions system, if not connected properly has a significant impact on how the truck runs then? What all does it affect? Idle speed? Fuel consumption? Seems like those two would be affected. It would make sense since my idle is high as hell. DuraSpark sounds like a good option after all. I'll have to start looking around for the parts on my pick n pull runs and keep researching it so I'm prepared when I'm ready to do it.
Thanks again for the info!
Z

Edited to add: By the way, the bad stumble was caused by a severely clogged fuel filter. I changed it out tonight and the gas that came out of the filter at the carb was straight rust colored and a lot of rust flakes came out as well. Crazy part was when I went to change the in line filter, there wasn't even one there! Just a piece of rubber gas line clamped on where the filter should have been. It was no wonder the one at the carb was so bad.
Runs much better now. Even got a little more power out of it. Next is the carb rebuild so I'm not leaking gas out of the front of it until I can get the duraSpark put together.

dangerranger83 · Dec 20, 2009

If this is the air pump we air talking about it pumps outside air into the CAT to help burn up hydrocarbons.

Thermactor question, Not egr question.

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