Too much power problem!

[eleblanc]

I was driving down the highway today at around 60mph. When suddenly the truck started to accelerate...ALOT...Like if i'd be full throttle and emptying a bottle of NOS. Within 5-7 second the EGT went up 250 deg F and even engine temperature raised 10 deg F very quickly.

So i let the throttle go for a few second, then apply throttle again. But the thing was like on and off, and pulling like crazy. So i coast to the side of the highway to let the thing cool while i check what is wrong. I don't see anything, so i get back in to get to the next exit. Still, the throttle was on / off and the truck accelerate like i never seen...i mean ALOT. While i'm trying to maintain speed to reach the next exit i though that maybe the waste gate hose disconnected.

So once i'm stop again, i check the hose and it seem ok, but i don't trust the T i installed with the bad connection that came with the boost gage. So i pull it off and find a plug. I try the truck again and same thing. So i start looking around and find that the hose from the throttle body that goes on the fuel pump was disconencted. So i reconnect it and put a tierap. And that was it. What is that house for? Seriously the increase in power is mind blowing (i guess for a turbo engine).

When i removed the T for my boost gage i did a few hundred feet to test it. But i had to turn around, you should have seen the cruiser spin the wheel and lay some good rubber on the tarmac...

Good thing i discovered this before my dyno run ;-) But what is it for?

[lshobie]

I can't remember about the 3B - but maybe it is a vacuum advance for your timing?? Might make sense.

[Tapage]

Your IP funtion in relation to the vacc created at the TB .. actually ( or at least in my 2H ) the TB had a butterfly that it's all control that you have to acelerate or not ..

this butterfly in the TB reate a vacc that said to your IP put more fuel into your engine ..

I thought there is a more cientific explanation .. but here is the idea ..

Also .. when this hose was craket or disconected your IP proceed to inject all diesel that it can do ..

[eleblanc]

Originally Posted by Tapage

Your IP funtion in relation to the vacc created at the TB .. actually ( or at least in my 2H ) the TB had a butterfly that it's all control that you have to acelerate or not ..

Also .. when this hose was craket or disconected your IP proceed to inject all diesel that it can do ..

Ok tapage what is a IP TB and VACC

Also i didn'T notice any smoke? with alot of diesel i should have seen smoke?

[Moe R]

Hey Eric
One of those clearish tubes that u told me to clamp barfed off ? ( I hate when that happens ). So U put it back and all is good??

[crushers]

i had this happen on a turbo'd 3B in a BJ60...amazingly fast!!

check all your lines for prope connection.

quite a rush actually...

Originally Posted by eleblanc

I was driving down the highway today at around 60mph. When suddenly the truck started to accelerate...ALOT...Like if i'd be full throttle and emptying a bottle of NOS. Within 5-7 second the EGT went up 250 deg F and even engine temperature raised 10 deg F very quickly.

[eleblanc]

On my truck the hose are black each side of the throttle body. Turboglide supply 4 colar to tight them. But i only had the two on the throttle body installed. Crazy the power i had.

[MOTERRA]

too bad they don't produce power like that all the time...lol

[eleblanc]

Originally Posted by MOTERRA

too bad they don't produce power like that all the time...lol

I would be hanging at the drag strip not in the trails....

[Tapage]

Originally Posted by eleblanc

Ok tapage what is a IP TB and VACC

Also i didn'T notice any smoke? with alot of diesel i should have seen smoke?

Hola Eric ..

IP = Injection Pump

TB = Throtle Body

Vacc = vaccum

About the smoke, not sure .. maybe more boost created and can't see smoke anycase . . ?

Edit: P.S. Got the Toyota owner mag where you make the cover .. !

[eleblanc]

Originally Posted by Tapage

Edit: P.S. Got the Toyota owner mag where you make the cover .. !

That is a old edition? it takes that long to get to panama?

[Tapage]

Originally Posted by eleblanc

That is a old edition? it takes that long to get to panama?

Naaa I miss it from my subscription .. and found in eBay last week .. and sure bid on it and win

[eleblanc]

Originally Posted by Tapage

Naaa I miss it from my subscription .. and found in eBay last week .. and sure bid on it and win

Really? people are putting the mag with my truck on the cover on ebay?? Wow.

[joshoisasleep]

Haha I had that happen a couple times. I know what you mean the power is insane... I guess it just gives you a massive fuel/air ratio? I'd be interested if someone could explain it in detail. I can't believe you actually drove for a few seconds like that.

[Tapage]

Originally Posted by eleblanc

Really? people are putting the mag with my truck on the cover on ebay?? Wow.

Yeah .. why not .. anycase you will surprise on how many weird things you can found @ eBay ..

[lostmarbles]

Sounds like the hose that connects "the venturi in the air intake manifold" to the "vacuum side of the diaphragm on the injector pump" came off.



In normal operation, the level of vacuum in this hose controls the position of "the rack" in the injector pump and this directly controls the quantity of fuel fed into each and every cylinder of your engine. Foot off the accerator, means the butterfly valve in the intake manifold is almost completely closed. So air is rushing at top speed through the venturi. This produces maximaum vacuum in the venturi which pulls the rack into the "minimum fuel quantity" (engine idling) position. On the other hand, if you plant your foot on the accelerator - the butterfly opens wide - so the airspeed through the venturi drops dramatically. This dramatically reduces the vacuum that's been pulling the rack (via the leather diaphragm). - So the spring is able to move the rack towards the "maximum fuel" (maximum power) end.

Now if the hose comes off. - There is a COMPLETE absence of vacuum - which is not normally achievable under any other circumstances when the engine is running. So your engine gets more fuel that it has EVER got before!!!!

What is really scary is that "high power" still occurs with the butterfly valve closed (foot off the accerator). --- I've tried it by taking off that hose while my engine is idling! She goes up to maximum revs in the blink of an eye!!!!

So please please please. Make sure that hose can never come off again. And such an event in a vehicle that has had the EDIC control replaced with a manual pull-cable could be DISASTEROUS!!! (Because you can't shut the engine down so easily as by just turning off the key.)

[eleblanc]

See the tierap this is where it disconnected...

[joshoisasleep]

Originally Posted by lostmarbles

And such an event in a vehicle that has had the EDIC control replaced with a manual pull-cable could be DISASTEROUS!!! (Because you can't shut the engine down so easily as by just turning off the key.)

Cool thanks for the explanation. One thing I would note though is that when your engine does this and goes into Ultra Mode everything can get really hot. I would suggest not turning off your engine but just putting it in neutral, pulling over as fast as you can, hopping out and re-attaching the hose. It's really easy to reattach when it's hot, and that way you avoid high temperature shutdown...

[Tapage]

Thanks for the scientific explanation ..

Just wondering if the other side it's .. ?

[lostmarbles]

Originally Posted by joshoisasleep

Cool thanks for the explanation. One thing I would note though is that when your engine does this and goes into Ultra Mode everything can get really hot. I would suggest not turning off your engine but just putting it in neutral, pulling over as fast as you can, hopping out and re-attaching the hose. It's really easy to reattach when it's hot, and that way you avoid high temperature shutdown...

I see what you're getting at in wanting to protect your turbo but if you were to HEAR your engine in that situation I don't think you'd want to do that. (Leave it running in neutral till you put the hose back on - that is.)

It would be screaming at higher revvs than you ever thought possible

But then - looking at eleblanc's photos now - It is not clear to me that it is in fact the venturi/vacuum side hose that came off.

Here's how those hoses sit on my simple little B engine:



Disconnecting that hose marked "vacuum side" is what causes my engine to immediately scream up to its revv limiter.

It now looks like eleblanc disconnected the other side - which actually gives no noticeable effect on my engine . (I say this because of where his hose (that came off) connects to his injector pump diaphragm housing. Bearing in mind that his intake manifold is considerably different to mine - so looking at it alone - I would be unsure which would be the venturi/vacuum connection on it.)


PS. This thread is what triggered me to experiment by removing my hoses. I'm going to read it again now just to make sure that I'm recalling correctly what I learnt then. (Alzheimer's could be doing its dirty work?)

http://forum.ih8mud.com/diesel-tech-...w-kill-3b.html

(Hmmmm. Whatderyerknow. I was recalling correctly.

[Tapage]

Again my question will be .. which it's the other side " line " job . ?

[lostmarbles]

Originally Posted by Tapage

Again my question will be .. which it's the other side " line " job . ?

Yes. If he got "maximum power" when the "other" hose came off - Then I'm completely lost as to why. Because as far as I know - that hose is just used to provide a "base reference pressure" (for want of a better term) for the "diaphragm actuator" (that moves the rack) to compare the vacuum in the other tube against.

With my engine that tube could be left open to the atmosphere - except then it wouldn't take into account the reduced pressure on the downstream-side of the airfilter. But here I'm not (or shouldn't be) talking about MY engine (non-turbo). Eleblanc's engine has a turbo - so his pressure in that "other" line is significantly higher than atmospheric instead of being lower. So if that "other" hose came off HIS engine - I theorise that he would be losing "boost" out of the open hose. (But it is a small hose so that probably has a minor effect as far as power-loss goes.) And the vacuum produced by the venturi (in the "vacuum" hose) would tend to pull the leather diaphragm a shorter distance (being no longer helped by the boost pressure on the other side of the diaphragm - because the hose feeding the boost pressure there fell off) so ............ hey..... the penny is dropping......................so.................. ............his diaphragm has less tendency to go towards the "idling-fuel-quantity end of the scale" and greater tendency to go towards the "full-power-fuel-quantity end".

Bloody hell - Once again the theory does correspond with what has happened in practice.

Removing that hose on my non-turboed engine does "next to nothing" but removing it on eleblanc's turboed engine gives "a big power boost" - and the theory tells us why.

Cheers Tapage (Thanks for making me think it through properly.)

Now that I understand which hose it was that came off and what was happening - please ignore what I said when I thought it was the vacuum/venturi hose that came off.

If I had a turboed engine - I'd be out experimenting now to see what actually happens if I was to remove that "reference pressure" hose with my engine idling.

[joshoisasleep]

I've had both hoses come off lots of times before I finally found somewhere that sold little hose clamps. You're right one seems to do more or less nothing, but I think I remember it still makes a loud noise and things heat up pretty quick anyway.

Yeah maybe you're right that shutting down would have been a better idea... I was also worried that maybe I would crack the block or something if I turned the engine off suddenly at high temps and high revs. In any case I did it my way several times... if you're quick it's not revving high for more than a few seconds.