Any help? Starts, and dies. Weird noise.

95_XR7

95_XR7

Registered User
Put the SC back together. It had a massive vacuum leak due to a bad gasket. Now, it won't even stay running longer than two seconds. The only thing that seems to be different is I noticed a bit of play in the bypass valve. Besides that, everything is unchanged. Upon starting, vacuum hits about 10-13 and then drops like a rock to zero. I checked for leaks but didn't see any. :confused:
I double checked all hoses and everything is right. Double checked all connections, re-torqued everything. Double checked all electrical connections.

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sounds he rotors are hitting each other......

ill get some pics up of my case in a few... its junk.. good thing its an early model case...


pull the blower belt see if it will run better...
 
The rotors are fine. I made suer when I was checking to see if there was any play in the snout, etc etc. The coating is even still about 85% intact. As far as cats are concerned,the noise is definitely coming from the top of the motor somewhere. The problem is, is that the noise is so hard to pinpoint.

To be honest, F1, for some reason that makes more sense then it sounds. I'll check pulleys in a bit when I go back out there.

The odd thing is, NOTHING has changed since taking it apart. All I did was put some Copper RTV on a gasket surface, and bolt it back together.

Another thing, the noise in person doesn't sound metallic at all. I can't even think of how to describe it.
 
Double check your belt routing,just to make sure things are where they need to be. You might check your tensioners to make sure they are free spinning.
How about your compressor, could it be seized, ??????
this is a weird one---good luck
 
You know what, every time I had the intake or intercooler tubes off that car it acted up. I remember when I changed the altenator and had the top intercooler tube off it would not run after and I never found out why. Here is what I did. Start the car and give it the gas and hold it to about 3 grand. It bucks and fights to run but keep it running. It will smooth out in no time and run perfect again. It happend twice to me. Its something about the car it self? It might not be the case this time but it cant hurt. Before you do this though take off your belts and check to see that everything is turning free.
Mark
 
scbird1 said:
You know what, every time I had the intake or intercooler tubes off that car it acted up. I remember when I changed the altenator and had the top intercooler tube off it would not run after and I never found out why. Here is what I did. Start the car and give it the gas and hold it to about 3 grand. It bucks and fights to run but keep it running. It will smooth out in no time and run perfect again. It happend twice to me. Its something about the car it self? It might not be the case this time but it cant hurt. Before you do this though take off your belts and check to see that everything is turning free.
Mark
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I'm beginning to think it's cursed :D:p
Nah, it seems everytime I bump a wire the car acts up, so the sooner I rebuild that harness I have, the better.
But yeah, on my way out there now.
 
Checked tensioners, atleast the ones that apply and they are all good. They are new anyways, so I wasn't much worried there. SC pulley is fine. Compressor spins freely, as does alternator and every other pulley.
Alright. Wrote all that and then decided to try starting it after resealing the top. I noticed the two front bolts for the top are kinda ******. Anyways, no luck as the same exact thing happens. If I give it gas it just sits there and misfires. If I hold the gas steady it just prolongs the inevitable dying of the car. The thing won't make above 10in vaccum. I did notice one time it tried dying, dropped to about 300rpm and then shot up to about 2000, followed by a quick dying.

It honestly sounds like a belt is too tight but they are all fine.


Screw it, this thing is coming back apart, again. I just can't believe it's a leak of any kind, but with it only making 10in vaccuum, and misfiring, it can't be a belt.
 
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almost sounds like your getting weak spark. Or possible the harness has a short or is corroded witch leads to higher resistance. just a thought.
 
1990XR7SC said:
almost sounds like your getting weak spark. Or possible the harness has a short or is corroded witch leads to higher resistance. just a thought.
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good point. but what the hell is the noise?

Update: The dying problem is definitely associated with a vacuum leak. TB is leaking an insanely large amount. As in, sucked my finger in type leak. Somehow the threads on the MP inlet are stripped, so two bolts barely have any pressure on the TB so there is a nice leak. Depending on how thick the wall is, I'm just going to tap to an M10 bolt.
As far as the sound is concerned, could that be the infamous IAC going bad?
 
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If you have un metered air that will cause havac. When the IAC goes bad it sounds like a dieing goose only when you go to shut it off. Sorry to hear shes not running right, Always loved that car. I have a black 96 LX right now that reminds me of 94 SC. The V8 needs alot more go though:rolleyes: Thats a picture of the 94 in my sig
 
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scbird1 said:
If you have un metered air that will cause havac. When the IAC goes bad it sounds like a dieing goose only when you go to shut it off. Sorry to hear shes not running right, Always loved that car. I have a black 96 LX right now that reminds me of 94 SC. The V8 needs alot more go though:rolleyes: Thats a picture of the 94 in my sig
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Yeah, how big of a leak would it take to kill the motor though?
To recap. I used Copper RTV on Intake Manifold - to- Inlet piece. I slowly tightened down all three bolts and slowly torqued them to specs to make a nice seal. I let that sit and started work on the vacuum hoses. Reconnected the ones I could and then went ahead and re-torqued the three bolts. Meanwhile, I also had torqued the MP inlet to the M90, using Copper RTV as well. I used the same process as before. I also undid every brass connection and resealed them with plumbers tape because a few had been leaking. After cleaning everything up, I bolted the SC in place making sure to attach the PVC hose, and all the vaccuum hoses. Torqued the SC in place.

I used Copper RTV on the SC top aswell.

Now, anyone see any problems with what I did, or could this TB leak be it? It's a shame I can't use some ether to find out myself, but the two seconds it takes for it to die just isn't ample enough time.

scbird1 said:
Sorry to hear shes not running right, Always loved that car. I have a black 96 LX right now that reminds me of 94 SC. The V8 needs alot more go though:rolleyes: Thats a picture of the 94 in my sig
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It's quite alright. It's just the small stuff that eats at me and then I create bigger problems:p
Yeah, the V8's are kinda slow. A nice PI swap fixes that.
I'm surprised I never noticed that before.
 
Just a thought...

Have you checked the starter? While not causing any vacuum leaks, it could cause a noise like that if it were not disengaging.

stigs
 
Can't see the video at work, but if it wont stay running, is surging, dropping rpm, it sounds like a vacuum leak I experienced. Mark would know all about that.If it sounds like the blower is making noise, could be explained by tight belts+spring coupler in blower snout+sudden increase/decrease in engine rpm. Make sure all SC top bolts are still good, they have a tendencey of getting stripped and not tightening down completely. Fix the TB leak and make sure your spark plug wires are correct too.
Phil
 
Phillio99 said:
Can't see the video at work, but if it wont stay running, is surging, dropping rpm, it sounds like a vacuum leak I experienced. Mark would know all about that.If it sounds like the blower is making noise, could be explained by tight belts+spring coupler in blower snout+sudden increase/decrease in engine rpm. Make sure all SC top bolts are still good, they have a tendencey of getting stripped and not tightening down completely. Fix the TB leak and make sure your spark plug wires are correct too.
Phil
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Ha, I thought of the top bolts awhile ago and checked them. They are stripped out so I'm debating on tapping to an M10 bolt. I shouldn't have any problems with this hopefully. Gonan do the same with the TB as well.

As for the noise, I'm actually wondering if it isn't the leak. I noticed when my brother somewhat sealed it, the car still died but the noise went away.
 
best bet is to fix the known problems, and see where you are at/go from there. Who knows, hopefully the blower noise will dissappear.
Phil
 
Fixed the problem guys. Used a 8mmx1.25 tap and tapped the holes for the TB-MP inlet and SC top to M90. I ended up going to a longer bolt as well to take advantage of a few more threads.

Hah, now I'm dealing with damage done to the car by bambi. This is never ending. Anyways, the thread is in Non-Tech.
 
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