quote:

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Originally posted by Tyrant89:
ok, we just replaced a head gasket, and now the car has small "stumble" at around 1800-2000 RPM. It's very slight, but when cruising within this rpm the surging is very annoying.

When slowly given throttls, I can feel thehesitation, but as the rpm's climb, the engine feels great.

Any sugestions?
89 LX w Novi 2K
42# injects,fuel ressure at about 39 psi. Heads, intake, cam.

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I have the same problem with my SC 96 cobra, but at around 3krpm. I think I need a retune. I wish that apex would do it for free. I already payed them for thier employees break time.
 

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Posted by Tyrant89 (Member # 1033) on :
 
Timing is around 9 deg, any less it drives like crap, any more, & it pings (on a hot day).

It has a chip from Byron, but still pings alot if I dont watch it, or if i try & run pump gas. I'm running about 95-96 octane usually
 

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Posted by st5150 (Member # 51) on :
 
Bump down initial timing another degree and check for vacuum leaks?
 

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Posted by st5150 (Member # 51) on :
 
Anyone know what the bleeder type screw on the side of a paxton fuel pressure regulator does?
 

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Posted by Tyrant89 (Member # 1033) on :
 
Thanks for the bleeder question, ST, I will ask around this week and try & find out if that's effecting my idle. I should have my pressure test and verify my timing by Thursday.
 

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Posted by Tyrant89 (Member # 1033) on :
 
OK, well, i havent found any vac. leaks yet.. but I'm still looking. I'm also going to change the plugs this weekend.

Paxton claim that the extra crew on my FP regulator is for auxiluary(sp?) reasons, say forrunning a gauge or whatever and is not for any kind of adjusting.
 

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Posted by st5150 (Member # 51) on :
 
Okay then, that makes sense. I'm willing to bet you're running both too much timing and too much fuel pressure. Even the slightest pinging on a blower car means you're running too much timing and risking popping a head gasket or worse.
 

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Posted by Jdub07 (Member # 2728) on :
 

quote:

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Originally posted by Tyrant89:
ok, we just replaced a head gasket, and now the car has small "stumble" at around 1800-2000 RPM. It's very slight, but when cruising within this rpm the surging is very annoying.

When slowly given throttls, I can feel thehesitation, but as the rpm's climb, the engine feels great.

Any sugestions?
89 LX w Novi 2K
42# injects,fuel ressure at about 39 psi. Heads, intake, cam.

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