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1G Is it normal for your coolant to pressurize while doing a BLT?

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I would take pauleyman's advice and start at the FIAV since you already had problems there and it's pretty simple to rule out. Disconnect the coolant lines from the TB and do another boost leak test. If air leaks from the FIAV nipples you've found your problem.

I think I found my problem. Air is leaking from the nipples. I'm gonna order the block off plate .
 
You want the plate that still allows operation of the ISC idle control solenoid. It will block off the FIAV in the lower throttle body, but still allows function of the ISC. If you use a total block off plate for both, then you may have other issues with proper idle or stalling.
 
So ifbi
Be careful not to confuse the ISC solenoid idle control motor with the FIAV. The FIAV does not have a plug. It is an internal valve in the throttle body behind the little brass freeze plug activated by the coolant to give a fast idle when cold. To disengage it is to bypass it with a blockoff plate. I thought that is what you installed already.

Leave the ISC plugged in. It controls the idle at operating temperature.

So I would remove the fiav and put the block off plate? Or does the block off plate go in between like the bypass plate?...
 
You want the plate that still allows operation of the ISC idle control solenoid. It will block off the FIAV in the lower throttle body, but still allows function of the ISC. If you use a total block off plate for both, then you may have other issues with proper idle or stalling.
There's a BYPASS PLATE (THATS WHAT I HAVE INSTALLED}. AND A BLOCK OFF PLATE
 
There are two kinds of plates. One is a block off plate for the FIAV only. And the other is a block off plate for BOTH including the ISC. I don't understand what you mean by bypass plate.

They're both installed between the lower throttle body assembly and the main throttle body.
 
I think I found my problem. Air is leaking from the nipples. I'm gonna order the block off plate .
I've logged 500k miles on dsms. I do not block off. Fiav has a job. If its bad I would diagnose the problem with it or replace the throttle body. If you block it off understand the possible idle issues that come along with that.
 
There are two kinds of plates. One is a block off plate for the FIAV only. And the other is a block off plate for BOTH including the ISC. I don't understand what you mean by bypass plate.

They're both installed between the lower throttle body assembly and the main throttle body.
.


One is a bypass plate. And one is a block off plate.
 

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There are two kinds of plates. One is a block off plate for the FIAV only. And the other is a block off plate for BOTH including the ISC. I don't understand what you mean by bypass plate.

They're both installed between the lower throttle body assembly and the main throttle body.
The plate for the fiav only is the bypass plate. The other plate that's blocks both is a BLOCK OFF PLATE..
 
There are two kinds of plates. One is a block off plate for the FIAV only. And the other is a block off plate for BOTH including the ISC. I don't understand what you mean by bypass plate.

They're both installed between the lower throttle body assembly and the main throttle body.
And they both don't get installed in-between... One does and the other you remove the fiav and put the Block off plate on.
 
Gotcha thanks. I guess I have the bypass plate on mine then. Along with a new ISC, it works great. Just a couple minutes of rough idling in the morning until it warms up...
I also bought a new isc and I'm still surging.. I think it's the air coming out the fiav nipples... I'm wondering if I can just cap the nipples on the fiav and then connect the collant lines.
 
If you have a bypass plate installed which blocks the FIAV only, then there shouldn't be any air coming out of the FIAV coolant nipples. Right? Did this result from a boost leak test? Seems odd...


I was thinking that also... Yes it result of a BLT because my original question was about my coolant being pressurized when doing a BLT... Somebody above said it check the nipples if air is coming out... I'm thinking about capping the nipples and looping my coolant lines.
 
I was thinking that also... Yes it result of a BLT because my original question was about my coolant being pressurized when doing a BLT... Somebody above said it check the nipples if air is coming out... I'm thinking about capping the nipples and looping my coolant lines.
If you have air leaking past the fiav you still have a problem. You pressurized the coolant. Blocking those nipples there will still be pressure behind them. Likely you will blow the caps off. You need to find the source of the leak and stop it. Honestly I wouln't waste my time with it. Just get another throttle body. You've already bypassed the fiav so the problem could be internal to the throttle body itself. You could take off the throttle body and pressurize those two nipples with a few psi. That will show you the other side.
 
If you have air leaking past the fiav you still have a problem. You pressurized the coolant. Blocking those nipples there will still be pressure behind them. Likely you will blow the caps off. You need to find the source of the leak and stop it. Honestly I wouln't waste my time with it. Just get another throttle body. You've already bypassed the fiav so the problem could be internal to the throttle body itself. You could take off the throttle body and pressurize those two nipples with a few psi. That will show you the other side.[/QUOT

I don't think they will blow off with clamps on them. That's reason my coolant was pressuring was the air in those nipples where leaking. So fusterating.
 
I have a spare 1g throttle body...pm me if interested and for pics

Do you know if it is a 1990 TB or and 91-94? Can you post a pic? How much do you want for it? I was looking at Mabe getting mine rebuilt for $140.
 
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