[sasilverbullet]

Need to know if anyone else experiences this problem...



When accelerating at almost full throttle or full throttle, in second gear, as it winds up, everything is smooth as glass except there's a little "burp" at around 3,800 rpm. This also happens in third gear. Haven't tested it out in fourth yet! <img src="/forum/images/smilies/968/tongue.gif" class="smilie" alt="" /> Can't find enough road!!



Anyone else experience this? If not, anyone have any ideas what might be wrong? Plugs, wires, fuel injection? Any ideas?

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[Greimann]

Can you define "burp" more accurately. Is is hesitation? Backfire, Surge?

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[sasilverbullet]

Definitely not backfire or surge. So that leaves hesitation...

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[Anchorman]

All I can contribute is that - whatever it is - I don't have it, so you're right to ask and search for the cause.

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[sasilverbullet]

I'll check the records and see when it had plugs last - that's what it feels like to me.

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[sasilverbullet]

Had new plugs back in Aug of 01 - looks like I'll be picking up a set on the way home tonight and putting them in.



My shop says to use NGK 7333, not the Bosch ones. Anyone else heard this?

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[Greimann]

Some of us run the NGK Iridium BPR6EIX or also stock # 6637.

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[Cloud9...68]

[quote name='sasilverbullet' date='May 11 2005, 09:15 AM']Need to know if anyone else experiences this problem...



When accelerating at almost full throttle or full throttle, in second gear, as it winds up, everything is smooth as glass except there's a little "burp" at around 3,800 rpm.  This also happens in third gear. [/quote]

Does it smooth out after the "burp" is done? Mine has a similar symptom at the same rpm, only under full throttle, and it never smoothes out, just keeps hesitating. I'm going to have it checked out this weekend. I suspect dirty injectors, but it could be one of a number of things. The distributor cap and rotor look fine visually. Somehow, it feels more like fuel delivery to me than ignition, but it's hard to tell for sure. I'll let everybody know what we find.

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[sasilverbullet]

It smooths out after the little burp.



You're problem sounds like fuel delivery, but don't rule out ignition wires, plugs cap or rotor. I've seen those items fail under heavy load.



Is there black smoke when you accelerate?



btw, I didn't do the plugs last night - I'll pick them up today...

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[Greimann]

Something that is plug related should be present at other RPM regions as well, but your approach is good. Cover the basics first before going to more complex causes.



It sounds like a lean hesitation to me. Maybe try some fuel injector cleaner too. That is pretty inexpensive fix.

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[sasilverbullet]

After 6 years of discussions on many a Porsche forum, might I recommend putting a can of Techron in and filling up with Chevron Premium?



Run that through and see if the problem goes away...

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[Cloud9...68]

[quote name='sasilverbullet' date='May 12 2005, 09:10 AM']After 6 years of discussions on many a Porsche forum, might I recommend putting a can of Techron in and filling up with Chevron Premium? 



Run that through and see if the problem goes away...

[right][post="4668"]<{POST_SNAPBACK}>[/post][/right][/quote]



I had about half a can of 44K, which I added to just under half a tank of gas, but it didn't help my problem at all. I'm not ruling out dirty fuel injectors, though. I'm going to take it to a mechanic I trust this weekend to get his take on it, and go from there. As I said, distributor cap and rotor look very good. It also got new plug wires recently, and I think it got new plugs then, too. I'm leaning toward the injectors, fuel pressure regulator, fuel pump, or maybe a sensor (throttle position sensor?). The fuel filter was also replaced not too long ago.

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[rustech]

I've had a few mechanics swear by Berryman's B-12 for FI cleaner. It is one of the best cleaners and doesn't do damage to the rubber in the fuel system like some others do. Might be worth a try.

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[sasilverbullet]

Burp gone, it was the plugs (and they were soaked in oil!) so I also resealed the cam cover.

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