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Old 01-17-2008   #41
XfireZ51
 
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Default Re: Exhaust changes causes problems

And?
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Old 01-17-2008   #42
Pete
 
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Default Re: Exhaust changes causes problems

Quote:
Originally Posted by rogerzr1
I did what you said Pete(pretty cool btw). The car didn't shut off at 75. I decided to take it for a drive with the power key off. It drove like sh**. When I applied the gas, the car shuttered and vibrated for a couple of seconds then smoothed out. My question is even though the car didn't shut off at 75, can the primary fuel pump still not be preforming correctly. Just wanted to see if this rang a bell with anyone. I plan on getting a guage tomorrow and trying what Jeff said to do.

BTW I appreciate everyone's help trying to educate my ignorant a**.
Yes,the primary could be performing poorly,you also have to remember the secondary Feul Pump will kick on at a certain throttle point.
I would then also try what Jeff said,take the secondary FP fuse out and try again,should have the stumble all the time if it's the primary.
If it turns out you do need FP just get one from a 1996 Chevy Truck 2500 the one with 454ci big block.
Pete
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Last edited by Pete; 01-17-2008 at 06:02 PM.
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Old 01-17-2008   #43
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Default Re: Exhaust changes causes problems

Quote:
Originally Posted by XfireZ51
And?
I'l add to this some injectors can Ohm out good but could leak like a fire hose.
To check this without a pressure gauge turn ignition to the on position and do a visual or have someone else keep an eye on the injectors while you turn ignition on.


Pete
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'91 #1635 PoloGreen 350 LT5
11.09 @ 129.27
11.04 @ 128.86
474RWHP 400RWTQ
http://www.youtube.com/watch?v=SFNFOhGGlR4
http://www.youtube.com/watch?v=ZlRIOMwaDYY
https://sites.google.com/site/peteszr1garage
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Old 01-17-2008   #44
XfireZ51
 
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Default Re: Exhaust changes causes problems

Pete,

That was my point. Having replaced injectors in August doesn't eliminate them as a problem. Thanks for clarifying that even ohming out injectors may not be enough. Wouldn't there be a gas smell if the injectors were leaking or plugs showing raw fuel?
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Old 01-17-2008   #45
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Default Re: Exhaust changes causes problems

Quote:
Originally Posted by XfireZ51
Pete,

That was my point. Having replaced injectors in August doesn't eliminate them as a problem. Thanks for clarifying that even ohming out injectors may not be enough. Wouldn't there be a gas smell if the injectors were leaking or plugs showing raw fuel?
I haven't smelled any gas smells. I am in no position to not listen to all of you all's sugestions. I was hoping that I could elimenate the injectors as a possible problem being they are new, but obviously I can't. I just want to get this thing figured out.
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Old 01-17-2008   #46
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Default Re: Exhaust changes causes problems

Quote:
Originally Posted by Pete
I'l add to this some injectors can Ohm out good but could leak like a fire hose.
To check this without a pressure gauge turn ignition to the on position and do a visual or have someone else keep an eye on the injectors while you turn ignition on.


Pete
Correct, just because they spec out in ohms, does not mean there is a issue with them being stuck open or closed or dribbling. I've had a few like that.
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Old 01-17-2008   #47
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Default Re: Exhaust changes causes problems

Quote:
Originally Posted by rogerzr1
I just replaced the stock exhaust with B&B and X pipe. The car seems to stumble in low rpm and hesitates a little during acceleration. The car acts like it wants to backfire, but doesn't. Any ideas?
Roger,have you done anything else to the car recently besides exhaust.

The symptoms you describe sound like bad spark plug wires,spark plugs or injectors.

You know what's funny is half the guys on here, had the car in front of them or took it for a test drive would figure it out in a second.

Pete
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'91 #1635 PoloGreen 350 LT5
11.09 @ 129.27
11.04 @ 128.86
474RWHP 400RWTQ
http://www.youtube.com/watch?v=SFNFOhGGlR4
http://www.youtube.com/watch?v=ZlRIOMwaDYY
https://sites.google.com/site/peteszr1garage
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Old 01-17-2008   #48
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Default Re: Exhaust changes causes problems

Quote:
Originally Posted by Pete
Roger,have you done anything else to the car recently besides exhaust.

The symptoms you describe sound like bad spark plug wires,spark plugs or injectors.

You know what's funny is half the guys on here, had the car in front of them or took it for a test drive would figure it out in a second.

Pete
I know, that's what is killing me. The injectors and spark plugs were changed in August. The spark plug wires were not changed.

The best I can describe it is:

As I step on the gas there is a little hesitation.
As the car speeds up it seems to catch back up and perform correctly until 3rd gear around 4500rpms it jerks (like there is no fuel) then continues to accelerate.

I don't know how better to describe it. When the power key is off, the car shakes and hesitates as I step on the gas. It seems like when the key is on, it makes the car drive better but it seems its just masking the real problem.

I don't know, now I am confusing myself.
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Old 01-17-2008   #49
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Default Re: Exhaust changes causes problems

Were the injectors replaced or were they cleaned?
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Old 01-17-2008   #50
rogerzr1
 
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Default Re: Exhaust changes causes problems

Quote:
Originally Posted by Jeffvette
Were the injectors replaced or were they cleaned?
I had them replaced with the Accel injectors.
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