Car won't start after changing plug wires and couplers

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SHOtime3

DohcYamahammer
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I just changed my wires, silicone couplings and intake gaskets, but now the car won't start. I made sure it was grounded to the same place as before and I even took the manifold apart again and everything looked ok. When I try to start the car it's makes a brief whining noise like a super charged car at idle and then dies. If the car does start it will be rough and at about 700rpm. When I put the manifold on it seemed like it was a liltlle off but it straightened out after I tightened it down.

Thanks
 
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SASHO91

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Vacuum leak, and a big one at that. Make sure all of the vacuum lines are connected, if they are, it's most likely something with the manifold.

Start the car and try and keep it running while your'e under the hood. Try and pin-point where the leak is, and go from there.
 

SHOtime3

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That's what I thought. I may just put the original couplers back on and see how they work.
 

Ishodu

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Make sure you leave the clamps on the couplers loose then tighten down the intake then tighten up the clamps on the couplers if you don't do this the intake will not set correctly and will leak.
 

SHOtime3

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Make sure you leave the clamps on the couplers loose then tighten down the intake then tighten up the clamps on the couplers if you don't do this the intake will not set correctly and will leak.

Thanks. I tightened the the manifold first then then the couplers but I tightened the couplers before I put it back in on the motor. So do I need to put the manifold back on the motor before I tighten the silicone couplers?
 

SHOtime3

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Thanks. I tightened the the manifold first then then the couplers but I tightened the couplers before I put it back in on the motor. So do I need to put the manifold back on the motor before I tighten the silicone couplers?

This thing just made me decide to walk to the gas station and get some cigs (I knew I should've left the SHO alone while the GF is borrowing my other car). Will someone let met me know if I was doing it wrong.
Thanks:wave:
 

SASHO91

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Just loosen the couplers with the manifold on the motor. And make sure that the intake is fully seated.
 

Storm-Chaser

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I agree - loosen-up the coupler clamps *and* the manifold bolts to ensure it's seated properly, then retighten the manifold bolts, then the coupler clamps.

The "whining noise like a super charged car" is a vacuum leak, large enough that the EEC can't compensate, hence why it won't run or even idle.


:burnout:
 

jthod

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Been ther, done that, vacuum leak. Make sure the nuts on the secondaries and the runners are also tight, I had one leak there.
 

SHOtime3

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I took the manifold apart and tried again made sure everything was tight and it still does it. I do keep having a problem with the manifold lining up on the motor untill I tighten a few bolts then it seems to drop into place. I'm going to take it apart again and rescrape the gaskets off and try again tonight when I get off from work. What kind of sealant do you guys use on the manifold gaskets?
 

SHOtime3

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I think I may have figured out my problem. I didn't use any kind of sealant on my manifold gaskets. Would that be causing the leak?
 

jthod

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You shouldn't need anything on them, unless they have been powdercoated. In that case, copper RTV. Otherwise, all you need is torque.
 

Storm-Chaser

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The only gaskets that might require any type of "sealant", are the steel plenum gaskets - which you simply clean-off and re-spray with a black spray paint. While a gasket could be the source of your problem, I've never heard of it being to the extent you're describing.


If it's still leaking, take it apart again and inspect all the gaskets. It's possible that the corner of one of the plenum gaskets folded-over on itself and is the source of the vacuum leak. Also check the silicone couplers to make sure one of the edges also didn't roll-under as you were sliding them on.

Did you re-use the old gaskets? If so, how old are they. Was there any apparent bad spots/sections? Were any difficult to remove when you were disassembling the intake?

How did you remove the old gasket material [that never wants to come off] from the butterflies? If you used a razor-blade, inspect the base to ensure you didn't accidentally gouge the aluminum surface.

If you can get and keep it idling (have someone start it while you work/hold the throttle return spring to keep the rpm up), spray some ether around the intake, the couplings, and the vacuum lines to locate where the vacuum leak is.


I think I may have figured out my problem. I didn't use any kind of sealant on my manifold gaskets. Would that be causing the leak?


:thumb:
 

SHOtime3

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^^^ I put a spare manifold on for now, but I'll bet I gouged the alluminum a little bit removing the old gasket material (razor blade scraper). I've double checked everything else to make sure it was tight and nothing folded over before. What do I need to do if the aluminum is slightly gouged?
 

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