Fuel System Cleaners ... all are Dexron III?

[T-Keith]

quote:

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Originally posted by brianl703:
What is in GM Top Engine Cleaner? I have never found an MSDS for it despite looking.

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I found an MSDS, but it actually tells more on the can. I'm going to make a seperate post for this stuff, in a couple days.

-T

 

[MolaKule]

Gary,

I too remember the Vacuum Modulators on automatic transmissions as well.

For the neophytes, a vacuum modulator was internal to the transmission and helped "modulate" internal transmission pressures for shiftpoint. (PowerGlides and early THM's).

The vacuum modulator was supplied vacuum from the engine's intake manifold. If the Vacuum Modulator's rubber diaphram broke, ATF would be sucked from the transmission into the engine's intake manifold, and if this occurred over long time periods before being detected, you might as well remove the heads and soak them in Gunk solvent, remove the intake valves, and grind off the carbon.

One of two ways to detect a ruptured Vacuum Modulator diaphram was a light puff of light blue smoke on shifts, or if you were a diligent Dipstick checker, you would see your ATF fluid level going down.

[ July 30, 2004, 01:17 PM: Message edited by: MolaKule ]

 

[T-Keith]

Vaccum modulators aren't really that old. GM used them into the 90s.

-T

 

[brianl703]

Some GM transmissions used both a vacuum modulator and a throttle valve cable. Most others used one or the other, not both.

 

[TallPaul]

quote:

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Originally posted by T-Keith:
Vaccum modulators aren't really that old. GM used them into the 90s.

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My wife's '92 Aerostar has a vacuum modulator.


Gary Allen: Love the idea of the vacuum line into the jug of ATF while going down the highway--great way to get rid of that tailgater!

Also, I had an '84 F150 that I had to do the "funky monkey" on the throttle to keep it idling at lights every time it rained (for 15 years it was like this

).

 

[Gary Allan]

quote:

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Gary Allen: Love the idea of the vacuum line into the jug of ATF while going down the highway--great way to get rid of that tailgater!

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I had often (well, once and a while anyway) thought that this would be a great "James Bond" type anti pursuit feature, using a windshield solvent washer pump instead of vacuum induction. This was back when I had 11 points on my driving record (about 24 years ago).

quote:

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ATF would be sucked from the transmission into the engine's intake manifold, and if this occurred over long time periods before being detected, you might as well remove the heads and soak them in Gunk solvent, remove the intake valves, and grind off the carbon.

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If I read this correctly, you're in disagreement with me.

Typically, on a V8 the vac-mod was tapped to only one runner of the intake, the one closest to the trans (typically the driver's side rear cylinder - as were most other things due to linkage etc.). This is why it was discovered as a combustion cleaner.

Object lesson. Daughter's Taurus (91-136k miles)..very close on emissions. Before the next inspection (one year later)..sucked 3 quarts of ATF through the PVC hose (3.0 V6). As I said ..it was virtually transparent in the application and passed a few days later with far better numbers (PA enhanced emissions on the dyno).

Again ..this is typically unnecessary with the relatively sterile conditions that advancements in injection and fuels (when compared to carburated engines of the 60s and 70s) have allowed us to take for granted. Most, even in perfectly functional condition, were so flawed that they accumulated a decent amount of carbon in their service life. The typical conditions in a modern day engine can be more easily remedied by a can or two of Seafoam in the tank.

This doesn't alter the validity of what I've done and seen as bona fide truth. This isn't some type of home brew "Slick 50" or "Prolong" type thing (although with the prevailing skepicism here, one could surely assume it to be so). I assure you it is not.

Anyone here own a "beater"? Do yourself a favor ..just for the increase to your knowledge base. Before you do a needed plug change ..pull ONE plug (assuming that you don't have ONE really bad cylinder - if so ..pull that one). Apply ATF into the intake ...drive down the road until smoke is gone. Pull plugs. Any deposits on the plugs should be gone (if you used enough) ..and there will be ABSOLUTELY NO RESIDUE from the ATF on any of them. This should confirm this as (at least) leaving nothing behind. The rest you can take on faith by the dispelling of the myth that it will leave an ash ..for any acumulative agent should surely foul the plugs.

I'm, naturally, happy to have us agree to disagree on this.

[ July 31, 2004, 12:37 PM: Message edited by: Gary Allan ]

 

[T-Keith]

quote:

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Originally posted by brianl703:
Some GM transmissions used both a vacuum modulator and a throttle valve cable. Most others used one or the other, not both.

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Your right GM used the vacuum modulator for shift pressure and the TV cable for shift timing. Very good system. Older systems used a vacuum modulator and a kick down cable.

-T

 

[Bror Jace]

Thanks to everyone who participated. I posted a link to this thread on the other forum. The person who's comments which were the inspiration for this thread got a kick out of it and may even join here.

--- Bror Jace