Author Topic: Help with loss of power (Read 32618 times)

KappaSky · « **on:** January 17, 2021, 08:57:36 AM »

2007 Redline. Problem just started at the end of last year. No changes for the year. So it?s been running great up to this point.

The problem is a sudden loss of power, bog when into boost around 5k RPM.

Air filter clean, MAF appears fine, cleaned, checked all hoses for leaks - turbo to intercooler to throttle body. No apparent leaks in vac lines.

Runs perfect otherwise. Can add boost, just not mash the gas up to 5k. No Codes...ever.

It has a few aftermarket parts, CAI, charge tubes, HFC, Solo Exhaust. Trifecta tuned.

Even tried swapping the factory cat back to make it less free flowing.

Could this be a HPFP slowly failing?

Out of things to check. Any thoughts would be appreciated.

Sly Bob · « **Reply #1 on:** January 17, 2021, 06:00:56 PM »

My first thought was the cat but you've eliminated that.

That said, I had a similar issue a few years ago. I generally always buy top teir fuel and only Shell V-Power NiTRO+ Premium I was on a road trip and found myself just about out of fuel. I stopped at the first gas station along the hwy at the first exit and filled up. It was an Exxon station but as it was a little out of the way, a few miles off the hwy, I was sceptical but needed gas.

After a fill up it ran fine for about 45 minutes to my destination and around town when I was there. Spent a few days there and then headed home, it was about a 5 hour drive. About 3 hours or so from home I was starting to have issues as you describe, the car was bogging at higher revs but like you, I had no codes set at all.

The LNF seems to be very particular about fuel. Now I have to add that my car is tuned and was tuned on Shell premium with no ethanol. Took a few tanks of gas for it to settle down and after that, I never had an issue with it again.

Have you bought fuel from somewhere you haven't before? As you've eliminated pretty well everything else it could well be a fuel issue.

LatinVenom · « **Reply #2 on:** January 17, 2021, 06:25:56 PM »

Who makes the CAI? We know the only one that works well is the GM anything else and you have issues.

Sly Bob · « **Reply #3 on:** January 17, 2021, 06:43:23 PM »

You state that you checked all the hoses for leaks on the charge side? Did you pressure test it or just check it visually? Generally with any sort of boost leak I believe a code is set but it might be something to check after a few tanks of good top tier fuel.

KappaSky · « **Reply #4 on:** January 17, 2021, 06:55:40 PM »

CAI is a GMPP

All hoses and connection visually and mechanically checked, tightened 4 times now.
Tried disconnecting the power for a day as well, in hopes of resetting anything.

I?m at a loss. I guess I can start randomly swapping parts, but a little upsetting as there is nothing readily apparent to me. At least if it had a code, there would be a starting point:(

Sly Bob · « **Reply #5 on:** January 17, 2021, 07:04:04 PM »

Which is why I suspect it's a fuel issue, could you have bought some bad fuel? Do you ALWAYS buy from the same place?

KappaSky · « **Reply #6 on:** January 17, 2021, 07:22:50 PM »

Yes same place for fuel all the time. Limited places to get 94.
To be fair, that could have been a bad tank. I?ll see if I can get a few tanks of gas through it next year.

Sol Asylum · « **Reply #7 on:** January 18, 2021, 01:32:26 AM »

How many miles are on it? Are you seeing it make the same boost pressure or has that dropped?

Gentleman Jack · « **Reply #8 on:** January 18, 2021, 02:18:04 AM »

Try putting stock tune back in and running it. If same problem persists, you can eliminate the tune. I realize you have likely had that tune for a while, but glitches happen. Reloading the trifecta tune from a clean copy also good.

Resetting fuel trims might also help, the battery disconnect or two cable tap would work.

KappaSky · « **Reply #9 on:** January 18, 2021, 08:15:59 AM »

Quote from: Sol Asylum on January 18, 2021, 01:32:26 AM

How many miles are on it? Are you seeing it make the same boost pressure or has that dropped?

56,000 kms or 35,000 Miles.
Yes it build boost smoothly and steadily until about 21psi, where if almost sounds like a backfire and looses all power. I release the accelerator and all is ?normal? again. No codes.

KappaSky · « **Reply #10 on:** January 18, 2021, 08:17:02 AM »

Quote from: Gentleman Jack on January 18, 2021, 02:18:04 AM

Try putting stock tune back in and running it. If same problem persists, you can eliminate the tune. I realize you have likely had that tune for a while, but glitches happen. Reloading the trifecta tune from a clean copy also good.

Resetting fuel trims might also help, the battery disconnect or two cable tap would work.

I can certainly reflash the original factory tune in the spring.
What is the two cable tap?

Thanks all

Gentleman Jack · « **Reply #11 on:** January 18, 2021, 06:51:49 PM »

Quote from: KappaSky on January 18, 2021, 08:17:02 AM

I can certainly reflash the original factory tune in the spring.
What is the two cable tap?

Thanks all

Two cable tap- disconnect both cables from battery and tap them together This will wipe any memory of fuel trims, radio stations etc. I think it should be understood- but- make sure these cables a completely disconnected from battery.

Pulling fuse for ecu has similar effect.

With that- your recent description really makes me think boost leak. Several of us have had that with no codes.

KappaSky · « **Reply #12 on:** January 18, 2021, 07:09:42 PM »

Interesting two wire tap process.

I?m at a loss of where next to look. I?ll check the intercooler to see if there is any ballooning on the intercooler. Is there a way to pressurize the system?

Sol Asylum · « **Reply #13 on:** January 18, 2021, 08:18:34 PM »

I know there is a thread on pressure testing here some place. It might even be one that GJ started.

KappaSky · « **Reply #14 on:** January 18, 2021, 08:39:50 PM »

I think I found it....

http://www.kappaperformance.com/forum/index.php/topic,5000.msg68111.html#msg68111

Sly Bob · « **Reply #15 on:** January 18, 2021, 08:48:31 PM »

Yeah that's it, really easy to check for leaks, I did mine just like that two years ago and I was actually quite surprised how many small leaks I had when I had thought I had it buttoned up tight. I used 25 psi if I remember and it you have the OEM intercooler I wouldn't go much higher. Why chance it and maybe swell the intercooler as a result.

KappaSky · « **Reply #16 on:** January 18, 2021, 09:24:50 PM »

Do you still have the cap Bob?

Sol Asylum · « **Reply #17 on:** January 19, 2021, 12:16:51 AM »

Yep that's the one I was thinking of.

I wonder how the professor is doing these days.

DeepBlueGXP · « **Reply #18 on:** January 19, 2021, 12:02:43 PM »

If you suspect it is fuel, you can pull the line off the fuel rail, put a hose in it to a bucket and turn the key on (not to start) and it will drain the tank.

Sly Bob · « **Reply #19 on:** January 19, 2021, 12:42:29 PM »

Quote from: DeepBlueGXP on January 19, 2021, 12:02:43 PM

If you suspect it is fuel, you can pull the line off the fuel rail, put a hose in it to a bucket and turn the key on (not to start) and it will drain the tank.

I almost did that by accident one time some years ago. I had a DDM inline fuel filter to install and didn't realize that the flared fittings on either side of the filter itself were loose and didn't catch it before I drove away. Went for a short drive and smelled gas after pulling in the garage.

Lots of gas in places where it shouldn't have been but fortunately all on the cool side of the engine. Fixed that pretty quick I'll tell ya'!

KappaSky · « **Reply #20 on:** January 19, 2021, 01:50:22 PM »

I have the DDM inline as well. Thought that could be the issue. Removing it yielded no change. Nice looking filter though.

Sol Asylum · « **Reply #21 on:** January 19, 2021, 02:19:34 PM »

It's possible you could have a partially blocked fuel injector that won't flow as well as it should. With the direct injection the injector is in the cylinder and you could get carbon build up on the injector.

KappaSky · « **Reply #22 on:** January 19, 2021, 03:25:31 PM »

Thanks sol asylum, certainly possible.
Will try to get a few tanks of gas through t when back out in the spring, with a good dose of injector cleaner. Part of the ?problem? is it doesn?t get used that much. Last year was even worse as there was nowhere to go from the pandemic.

KappaSky · « **Reply #23 on:** January 19, 2021, 03:27:28 PM »

DeepBlueGxp, I am not totally convinced it?s the fuel. So I?ll just go easy on it to burn up the tank of fuel in the spring and get some fresh fuel in. Fingers crossed!

Steelmesh · « **Reply #24 on:** January 19, 2021, 04:15:27 PM »

Just throwing it out here, worn plugs (opened gap) will cause spark blowout in high boost cars. Are you feeling torque dips and seems like the engine tune is "breaking up" at 5,000 WOT?

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Author Topic: Help with loss of power (Read 32618 times)