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04 lj with GRTOPS half cab conversion 05 rocky mountain 06 rubicon with banks sidewinder turbo
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So I installed a throttle body spacer on my 98 wrangler and now my engine wants to stall after applying the brakes...any tips guys?
take it off it won't do anything anyway i tried one didn't do nothing. they are a waste of money so is a programmer and cold air intake
 

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Welcome to the Forum Bilskie92,

What engine do you have? Tell us about your Jeep. Have you done anything else to it that might have caused the stalling. Are all your vacuum lines reconnected?

Good Luck, L.M.
 

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So I installed a throttle body spacer on my 98 wrangler and now my engine wants to stall after applying the brakes...any tips guys?
A properly installed TB spacer would not cause that. And a vacuum leak where it bolts to the air intake manifold would cause higher rpms, not lower rpms. Check things like the throttle linkage, cruise control linkage if it has cruise control, to see if there's any mechanical interference going on.

Then you can go ahead and remove the spacer. Spacers do literally and absolutely nothing for the type of throttle body the TJ, JK, and JL has since there is no fuel passing through it. Only air passes through the TJ's TB. Spacers can and do help but only in 'wet' systems like a carburetor or the first generation of throttle bodies that had a fuel injector screwed into them. All your TB spacer did was make the air passage longer which does absolutely nothing for performance. Really. Despite all the hype and that it might have changed how the engine sounds.
 

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2006 Jeep Wrangler Unlimited Rubicon, too many mods to list.
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One of my suspicions would be the vacuum diaphragm on the brake system has a big leak, and the moment you step on the brake, it takes away your vacuum by letting a rush of atmospheric air in to the system. Test by pinching off the large (about 3/4” od) hose to the large diaphragm housing and depress the brakes again with the engine running. If it still stalls, that is not the issue. If it has no effect, it’s your likely culprit.
 

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2006 Jeep Wrangler Unlimited Rubicon, too many mods to list.
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That would raise the RPMS, not lower them.
It would certainly lean the bejeezus out of the mixture, which at first glance would indeed raise the idle Rpm. But what if all intake vacuum suddenly went to atmospheric pressure? on throttle body injected engines, wouldn’t that take most of the fuel out of the intake by bypassing the intake tract?
 

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The intake manifold can't be bypassed by such a leak, such leaks would feed air directly into the intake manifold. It wouldn't at "first glance" raise the rpms, a major vacuum leak to atmospheric pressure would cause the rpms to go sky high.
 

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Ladies and Gents please don't take as an insult but what's the need for the throttle spacer? Take that puppy off. The 2.5 and 4.0 will operate plenty fine without it. If your looking for more power I would try an alternative.
 

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1999 Wrangler, TJ, 4x4
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A half inch worth of throttle body spacer will give you additional rpm, but you are going to sacrifice some low end grunt to get it. Get ready for some rough idle to go with it, since the intake and exhaust manifold are on the same side of the block. Its next to impossible to drop the intake temperature without development of condensation. The IAC is going to be a problem to keep clean for obvious reasons as well. Short version Throttle Body spacer isn't always a good idea.
 

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if installed properly it shouldnt harm anything, but it doesnt help anything either. Jerry's response in post #5 is spot on. if the fuel is mixed after the throttle body, they offer little if any value
 

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Signs Of A Faulty Brake Booster Check Valve
  1. An Aggressive, Hard Brake Pedal. This is when the brake pedal feels stiff and challenging to press. ...
  2. A Spongy, Squishy Brake Pedal. ...
  3. A Brake Pedal That Has A Swiftly Changing Response. ...
  4. A Vehicle Engine Stall.
 

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Discussion Starter · #20 ·
Update guys. I went through the paperwork the previous owner did to the jeep. I guess the tcc was replaced and other transmission work was done. I'm lost on what to do here. Any advice would be sure appreciated.
 
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