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Alot of hesitation / light thuds under medium and hard accelleration [UPDATE: Solved]

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Old 03-05-2018, 10:48 PM
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Very true.

Anyhow lets begin with the small stuff first. This Wednesday Im going to order a MAF. Should I just go with one of those $35 eBay replacements?
https://www.ebay.com/itm/Mass-Air-Fl...BYYH-K&vxp=mtr

a Delco from Autozone?

Or should I go ahead and get a larger MAF right now? I'm thinking the $35 eBay replacement wont be a huge financial risk and should atleast tell me if the problem is the MAF or not while not being a huge loss if / when I upgrade later versus spending nearly $200 for a Delco replacement only to throw it away later.. The only thing Im slightly worried about is compatibility. What do you think?

---

After I address the MAF, I'm probably going to just collect the exhaust parts and not drive it, then later pull the motor and begin building it as well.
Old 03-05-2018, 11:18 PM
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For sensors, I am a big fan of using the original Delco stuff. I have had lots of trouble with knock off stuff. Either way you will need to get it tuned. If you were in my neck of the woods, I'd charge you $100 and a case of beer. But unfortunately, I can't help you with that. MAF's always need to be tuned. You might get lucky, but it doesn't have to be huge to make huge power. Bigger isn't always better on LS engines. It just depends on your goals.

You should start with that first. Set a power goal, come up with a budget, and take your time. That's the first thing a lot of guys fail to do when building an engine. Build it with the end in mind, and what you want it to be in the end. Then deciding on parts starts to get easier.

Consider if you are planning on adding a blower or nitrous, or just sticking N/A. You really don't want to waste money on parts that won't work well with your result in mind, if that makes sense.

You can try the knock off sensor and see if it works. I mean you never know, but $35 bucks is still $35 bucks that could of been used towards a proper Delco replacement. Look for them online, they are generally cheaper than at autozone or other parts stores. Summit sells all that stuff too. And if you're military you get a discount too. Fwiw.

You know, I have a stock MAF laying in the garage somewhere...
Old 03-05-2018, 11:37 PM
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Originally Posted by wssix99
Does it open and then go straight to full-geyser on you?
Originally Posted by ChopperDoc
For sensors, I am a big fan of using the original Delco stuff. I have had lots of trouble with knock off stuff. Either way you will need to get it tuned. If you were in my neck of the woods, I'd charge you $100 and a case of beer. But unfortunately, I can't help you with that. MAF's always need to be tuned. You might get lucky, but it doesn't have to be huge to make huge power. Bigger isn't always better on LS engines. It just depends on your goals.

You should start with that first. Set a power goal, come up with a budget, and take your time. That's the first thing a lot of guys fail to do when building an engine. Build it with the end in mind, and what you want it to be in the end. Then deciding on parts starts to get easier.

Consider if you are planning on adding a blower or nitrous, or just sticking N/A. You really don't want to waste money on parts that won't work well with your result in mind, if that makes sense.

You can try the knock off sensor and see if it works. I mean you never know, but $35 bucks is still $35 bucks that could of been used towards a proper Delco replacement. Look for them online, they are generally cheaper than at autozone or other parts stores. Summit sells all that stuff too. And if you're military you get a discount too. Fwiw.

You know, I have a stock MAF laying in the garage somewhere...
If even a stock Delco will need a tune, I should probably just go ahead and upgrade fully to what I'm going to need. I intend on about 600 WHP and 700 at the crank on a super charged setup. I was thinking I would need a bigger MAF for that.

If thats the case should I just get a SLP 85mm and tune it, or a TSP 100mm and their LID?

For the motor I havent fully decided what Im going to go with but I'm thinking I'm going to need a forged LQ4.

Last edited by Need4Camaro; 03-05-2018 at 11:44 PM.
Old 03-06-2018, 12:50 AM
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The size of the MAF isn't the limiting factor. It's actually in the tune. On the 4th gens PCM (gen III PCM) the limit is 512 grams/sec. this can be scaled, but at some point you'll run out of frequency. If you're going to supercharge it, then I don't see why it's going to make much of a difference as to the physical size of the MAF or housing. You're going to push air through, not drag it in naturally. I could be wrong there, but there are lots of guys running smaller than 100mm making big power with blowers.
Old 03-06-2018, 01:18 AM
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Originally Posted by ChopperDoc
Bottom line, unless you get something super rare, cars are always a terrible financial investment.
I'd go a step further and say that a rare car is *still* usually a bad investment, from a growth perspective. Once you consider insurance, any storage costs, maintenance/upkeep, any registration fees/taxes, etc., it's very rare to make a long term profit above and beyond what you'd make in a more traditional form of investment. Unless you can buy a car for a steal and flip it quickly, and/or you're a professional in the automotive business, then forget about owning any car with the likelihood of making a respectable net profit.

Originally Posted by ChopperDoc
For sensors, I am a big fan of using the original Delco stuff.
I definitely agree here.

Originally Posted by Need4Camaro
If even a stock Delco will need a tune, I should probably just go ahead and upgrade fully to what I'm going to need.
I don't see any reason why a stock/GM, application-correct MAF would require tuning for proper operation on a stock example of said application. Of course, there's always some optimization to be found when tuning even a stock car, but they didn't roll off the assembly line needing a custom tune just to run right.
Old 03-06-2018, 06:22 AM
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Originally Posted by Need4Camaro
Not IMMEDIATELY, it is more like you watch the fluid in the radiator begin to bubble, alot, then it starts chugging out the sides of the fill neck, then it starts getting violent and shoots UP to the hood and won't stop unless I shut it down. So it kind of like builds up over time but its a fairly short period of time.
This sounds like normal thermostat and flow activity but just that the gasses (and maybe also the design of the radiator inlet) are causing the problems.

Originally Posted by Need4Camaro
I'm honestly beginning to believe you're right considering the missing coolant and no leaks. I haven't been driving it since. I personally feel comfortable replacing the head gaskets on my own but I feel like if Im going to go that far I may as well just address the motor before anything else...
Maybe I missed it earlier, but did you do a pressure test? That should tell you for sure if you have a head gasket problem.

If you pressure test good, you could have a problem with the water pump. It's designed with an air chamber right next to the water inlet and there are conditions where it can suck in air and pump it into the system. (This happened to me and it was a real bugger to isolate.)

Old 03-06-2018, 12:39 PM
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I might under the assumption that this car has already been tuned at some point, and if so will require a tune for even a stock MAF. The other thing is, you need to get the exact stock replacement, since this can vary from one sensor to another.

In any case a Delco replacement will probably run much better than the one you have, and you might not need a tune. I just don't want you to think that any replacement is plug and play.

As far as the water pump goes, that is an interesting issue, and I can't say I've ever seen that. Maybe that's the problem... hard to tell without further investigation.

I'd at least pull the plugs and have a look.
Old 03-07-2018, 04:37 AM
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Car hasn't ever been tuned. Going to order a Delco today. The Water Pump is a Duralast replacement, actually its my second Duralast, the first one had a bad bearing right out the box.
That was a BRAND new water pump.

The one I'm using now I've been using for about 2 years. (It's not whining like the first one in the video.) If it has to be replaced, I'm going with a LS3 Delco Pump.

I'll see about pulling the plugs. I really hate doing that on this car because that usually results in breaking the wires.
Old 03-08-2018, 04:42 PM
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UPDATE:

I replaced my MAF and that fixed the issue. No more hesitation or bogging under a load or misfires. SES also went off but we'll see how long that lasts. I'm am wondering if the air/fuel mixture was throwing off the O2's causing them to throw a code...

ALSO, LOOK WHAT I FOUND:






That's my SLP lid at the neck where the MAF goes. The crack extended past the neck and I am believing over time moisture and water was inhaled and destroyed my MAF which is why it died fairly new.


OLD MAF below:





Also regarding the coolant / possible head gasket issues. I know someone said one of the symptoms is overhearing. This is a photo of my PLX Digital OLED reading somewhere around 219 while on the interstate. (It's connected to my OBDII port) That's about where it stays. Temp gauge shows it's much lower than that but what do you think.

Old 03-09-2018, 11:29 AM
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that tear in the MAF/TB coupler would cause a significant vac leak post MAF and 02's would read lean and command PCM to dump fuel which would cause you to run rich
Old 03-09-2018, 05:27 PM
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Originally Posted by ******
that tear in the MAF/TB coupler would cause a significant vac leak post MAF and 02's would read lean and command PCM to dump fuel which would cause you to run rich
Is there a good possibility my old MAF isn't even bad?

Also what should I do with the LID? replace with another SLP? try to have it repaired? go for another LID? (and which one would you recommend that I wouldnt need to worry about cracking?)

Last edited by Need4Camaro; 03-09-2018 at 05:33 PM.
Old 03-10-2018, 07:38 AM
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Originally Posted by Need4Camaro
Is there a good possibility my old MAF isn't even bad?
Dunno. Is the tear in the connector after the MAF or in the lid before the MAF?

If the tear is after the MAF, that very well could have been the problem. (The MAF would not have been measuring all the air getting into the engine.)

If its before the MAF, then it's a maybe. A pre-MAF tear could have been causing turbulent air to go over the MAF elements, which could fool the engine. A pre-MAF tear could also "stuff" to bypass the air filter and do damage to the MAF, but you would probably see visual evidence of that. (if it happened)
Old 03-10-2018, 12:23 PM
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Originally Posted by wssix99
Dunno. Is the tear in the connector after the MAF or in the lid before the MAF?

If the tear is after the MAF, that very well could have been the problem. (The MAF would not have been measuring all the air getting into the engine.)

If its before the MAF, then it's a maybe. A pre-MAF tear could have been causing turbulent air to go over the MAF elements, which could fool the engine. A pre-MAF tear could also "stuff" to bypass the air filter and do damage to the MAF, but you would probably see visual evidence of that. (if it happened)
Tear was before the MAF, the actual wires in the MAF look fine.
Old 03-10-2018, 07:07 PM
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Putting the old MAF back on would be an interesting test. Maybe that tear was upsetting the laminar flow over the wires? (If such a thing happened and a "stale" pocket of air developed around a wire, it would under-measure the amount of air going into the engine.)
Old 03-15-2018, 12:41 PM
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Originally Posted by wssix99
Putting the old MAF back on would be an interesting test. Maybe that tear was upsetting the laminar flow over the wires? (If such a thing happened and a "stale" pocket of air developed around a wire, it would under-measure the amount of air going into the engine.)
I may try this later as I still have the old MAF.

I replaced the LID with a FTP 76mm LID. I don't have the larger MAF so didn't go with the 98mm, maybe down the road I'll do that. Anyway... I feel a BIG difference between the FTP 76mm and the SLP, its so much more responsive and feels stronger than I've ever felt it before. Also I haven't gotten an SES for my cats again either.

So at this point its a night and day difference as to how it was acting before... No more hesitation, pulling stronger than it did even before it was hesitating.

I guess if I don't get an SES for my cats Im going to continue with my original plan and get my MWC 9" Rear, then I'll do exhaust.



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