few 2.8L questions

vanderson11 · Apr 21, 2014

So awhile back I bought an 85 ford ranger that had been sitting in a field for a couple months not running. After some new sparkplugs and a new ignition module the truck has been running great, but I've noticed a few things. After sitting for so long, mice had made there way into the vents and anytime I kicked the fan on, heater or ac or anything, I'd get a face full of mouse nest. I removed the blower motor from the firewall and cleaned out a bunch of leaves and what not. That seemed to help until I change it from outside air to inside, when I do that I still get crap coming through my vents, whether its the defrost or the panel vents. My question is how can I remove my panel vents, do they just pop out? My dash is in fairly good shape and I dont have a parts truck if I break anything. Is there another way into the vents besides removing the whole dash?

Now for my second question. While changing the spark plugs I noticed the smog pump...its just sitting there in its own little mess of lines, not mounted on anywhere. After checking some of the lines I realized one was not hooked up anywhere, and the one running to the cat had broke and just sat a sputtered air while the truck idled. Emission testing is not a big deal around here so I was thinking about ripping the cat off and straight piping it. Ive done some research and I've read that if you remove the emission stuff you should do a duraspark conversion, so my question here is can I remove my smog pump and some of the emission stuff without doing the duraspark conversion or will it kill my mpg and or make the motor sluggish?

Thanks in advance

RonD · Apr 21, 2014

You can remove the thermactor system(air/smog pump) and plug the holes, I assume it already has the shorter fan belt if air pump is unhooked.
But you need a cat converter, that's a Federal "beef", so leave it in place or replace it, cat converters generally out last a vehicle so wrecking yard cats are fine to use if they are not rusted out.

Older ignition systems have their problems but are fine to keep if repaired.
Carbs are not great for MPG, compared to EFI, but you can keep them adjusted to get the best MPG possible.

You could try a Shop Vac in reverse and blow out each vent to the main passage.

dangerranger83 · Apr 21, 2014

The factory feed back carbs and emissions stuff on those trucks became junk after so many years by not working right. Best advice is to go duraspark unless you are getting decent mpgs and power now. If the pump still works, bets are it will lock up one day on you. I found out that the belt that drives the power steering pump and water pump was the length needed to run the alt. and water pump when deleting the emissions pump.

As for a CAT, junk yards can't legally sell them so you will either have to plug yours off where the tube went in or get a cheap one from a parts store.

Sent from my SPH-L710 using Tapatalk

drsvox · Apr 21, 2014

regarding smog pump setup and to piggy back off this post: my 2.8 was running the smog and had the air check valve coming off the exhaust manifolds. however, seems it was modified: the check valve was cut off at the "Y" and a tube was welded from it, feeding into the exhaust before the cat.

so I have two questions:

-why mod it like that? and

-what does the original set up look like? does the check valve connect to the diverter valve, or...?

Thanks!

oh and you might be able to better access the vent ducts by pulling off the a/c evaporator core cover and pulling the core out...assuming you've got a/c and there's a evap core to pull : )

komoto123 · Apr 22, 2014

drsvox said:
regarding smog pump setup and to piggy back off this post: my 2.8 was running the smog and had the air check valve coming off the exhaust manifolds. however, seems it was modified: the check valve was cut off at the "Y" and a tube was welded from it, feeding into the exhaust before the cat.

so I have two questions:

-why mod it like that? and

-what does the original set up look like? does the check valve connect to the diverter valve, or...?

Thanks!

oh and you might be able to better access the vent ducts by pulling off the a/c evaporator core cover and pulling the core out...assuming you've got a/c and there's a evap core to pull : )

The check valve connects to the diverter valve i believe.

This tube that goes to the manifold

http://cdn2.autopartsnetwork.com/images/catalog/brand/standard-motor-products/full/SI_AV32_Front.jpg

Then connects to this diverter valve (ithink)

http://i.ebayimg.com/00/s/MjY1WDM2NQ==/z/~I0AAOxyQyJRmOJI/$%28KGrHqJ,!lwFFy5pmCo9BRmOJICd9w~~60_35.JPG

drsvox · Apr 22, 2014

good...those parts exactly and yes that's what I was thinking. One hose coming off the diverter had been blocked and I suspected that it once connected to the check valve.

thanks much for your input!

kimcrwbr1 · Apr 22, 2014

There are two valves off of the air pump I believe the diverter just switches the air off and on to the thermactor and the thermactor switches between the crossover on the manifolds or the cat. Both have a check valve. I just checked my book and some have the combination bypass control valves the bypass vents air into the engine bay. If it has one vacuum fitting and two hoses it is a bypass if it has one vacuum and three air hoses it is a control valve (thermactor). If it has two vacuum fitting and three hoses it is the combo diverter/control valve.

kimcrwbr1 · Apr 22, 2014

About five years ago when I was trying to get the computer to work in mine I found out the check valve for the crossover was bad and it pumped hot gasses through the control valve and the guts were all melted from the heat. You can try applying vacuum pressure to the vacuum pods on the thermactor and bypass and see if they even work. One should turn it off and the other switches between outputs.

drsvox · Apr 22, 2014

ok so, the attached picture is how mine came out of the engine compartment. the bottom hose connects to the smog pump, that i'm (almost) sure of.

on the diverter valve, where do the two free ports connect? i'm assuming one goes to the check valve coming off the exhaust manifolds. and the other?

bottom line is I'm dumping huge amounts of money into my project and I desperately do not want to jack anything up come engine break in time...

kimcrwbr1 · Apr 22, 2014

Yes the bottom one is the bypass and air vents out the silencer on the back side the upper one is the control valve one goes to the crossover and the other to the cat. If you can put a new check valve on the crossover and hook it back up the hose going strait up goes to the crossover and the other goes out to the cat. just hook both vacuum lines to manifold vacuum

drsvox · Apr 22, 2014

Thank you! Makes sense to me now and I appreciate the help.

One final: after your reply (and the return of a three year old memory), I now remember that the crossover was welded (poorly) shut, the hose coming off the side port was blocked, and the top port was connected to the check valve into the cat.

but making sure I understand you correctly: top goes to crossover check valve and side goes to cat. huge help! thanks!

and gotcha on the vacuum!

kimcrwbr1 · Apr 23, 2014

I did the duraspark conversion almost three years ago but I am still using the air pump. Are you still running with the computer?

komoto123 · Apr 23, 2014

Maybe this will help you. It should of been on your truck somewhere

http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/07/7f/d6/large/0900c15280077fd6.gif

kimcrwbr1 · Apr 23, 2014

Yea it should be on the radiator support near the center and is color coded. Mine is a 83 also but you will spent less time at parts counters if you buy parts for a 1984 2.8. That is the 84 diagram.

kimcrwbr1 · Apr 23, 2014

Just checked my book that is the 85 vacuum diagram he doesnt have the TAS solenoid.

few 2.8L questions

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