Stumble at 3000rpm...

[mike_b_svt]

Hey Fellahs,

I've been searching around here and not finding what I'm looking for, so I'm posting.

I'm getting what feels like a loss of power / "flat spot" at around 3k rpm. Only seems to happen when i'm gettin on it. When I do a non-WOT, modest but aggressive acceleration it seems normal.

No mods. Only a K&N filter with a basic Diablosport Predator tune installed.

Recent work;
- Replaced Fuel Filter
- Cleaned & re-Oiled K&N Filter (careful not to go crazy with the oil).

So I'm thinking it is one of 2 things: dirty MAF Sensor and / or Vacuum leak.

What is the recommended cleaning agent for the MAF Sensor? I've seen a few writeups saying Carb Cleaner, and others saying not to use Carb Cleaner.

As for the Vacuum Leak. How the heck do you track one down? How do I tell if that is possibly my issue? Any info will be much appreciated!

Thanks in advance!

 

[Mineral_01']

Well as far as vaccum leaks, you can use the old school trick of soap and water sprayed onto the suspected trouble area. The soap and water solution will bubble on an area with a vaccum leak, this should only be done on a cold motor or one not hot enough to evaporate the water instantly.

 

[mike_b_svt]

Will it actually bubble for vacuum? Wouldnt' the vacuum suck the soap solution IN instead of blowing bubbles?

 

[Jimmysidecarr]

Well as far as vaccum leaks, you can use the old school trick of soap and water sprayed onto the suspected trouble area. The soap and water solution will bubble on an area with a vaccum leak, this should only be done on a cold motor or one not hot enough to evaporate the water instantly.

I don't think so.:dw::nonono:

Have you ever actually tried this? I would love to see the video proof.
How is a vauum leak going to bubble when the air is going in and not out?

Detecting natural gas leaks sure, but not vacuum leaks.:nonono:

Use choke or brake cleaner with the engine running, the idle will pick up when you spray near the leak.

Or use an unlit propane torch, the propane will make the idle pick up.

 

[Jimmysidecarr]

- Cleaned & re-Oiled K&N Filter (careful not to go crazy with the oil).

[ame=http://www.amazon.com/CRC-Industries-Sensor-Cleaner-05110-C/dp/B000EPQ2PS]Amazon.com: CRC Industries - CRC Mass Air Flow Sensor Cleaner, 11 oz., CASE OF 6 (05110-C): Automotive[/ame]

 

[mike_b_svt]

Thanks Jimmy, thats the next thing on my "to do" list. Just wanted to get some feedback on the possible Vac leak too while I was at it.

 

[Mineral_01']

Yes, I have actualy tried the soap and water methed on an older 302 based block. The intake manifold gasket was leaking and it bubbled just like I said. It was a large leak so I dont know if this will work with smaller leaks. As Jimmy has said, carb cleaner works as well. Hope this helps, good luck.