Guys I need to get some input from some of you that have probably been in my position.

The belt on my SC shreaded. I replaced the stock belt. During the process of replacing my stock belt I believe the MAF was damaged.

Moving along....... I got another MAF and installed it. Pulled codes and I am no longer getting MAF code, but i am still getting knock sensor code (0304).


The problem is this... The car CHOKES above 3.5 K. It runs semi strong from 0 RPM - about 3500 RPM then it BOGS!!! I mean seriously... It STRUGGLES to get to redline, and the power is all but gone!

For you S/C guys who ran with the supercharger piping intact while the supercharger wasn't running, did you experience anything similar?

I am really hoping that its just that piping choking the car for AIR, but I can't be sure right now.

Everynight i come home from work it starts to rain so I haven't gotten a chance to maybe extract an pop charger from my other car to test on it.

 

That shouldnt be that much of a problem. I ran my car with ALL the IC piping and pulling through the TC while the TC wasnt hooked to the exhaust during my testing.

Dixit

 

So you don't think the TC setup is a little different?

Anyway if the piping is not my problem, what else could it be?

 

Yes a TC setup is vastly different but I was trying to prove that it cant be piping because a TC setup can have as much as 3-4x more length of piping.

I think your problem is Knock Sensor related. If its really bad I can see it throwing very incorrect data to the ECU on if it is knocking or not. And the ECU can be retarded the timing to max levels.

Dixit

 

Knock sensor is becoming my only lead, but I thought everyone said at WOT the ECU goes into a mode that disregards information from the knock sensor?

This problem occurs strongest at WOT.

 

Just a shot in the dark, but you might check for a rag or something that could have gotten sucked up into the intake. Like Dixit says, just the presence of the additional piping shouldn't cause any driveability problems, and I think the blower not turning shouldn't cause that much restriction. Try removing the pipe directly connected to the maf and see if that changes anything.

 

Yeah i removed all the pipping up to the maf, and it still hesistates. I don't know what to do next but check the knock sensor. I am just a little reluctant because I've never heard of a knock sensor problem manifesting itself like this.

 

I very seriously doubt it's your knock sensor. Sounds more like a maf problem.

Did you buy a new or used maf?

 

A used MAF. I don't get the MAF code, So I have no reason to believe the MAF is the culprit.

I thought once i got the replacement it would be all good, but I was mistaken.

 

The reason to suspect the maf is the symptom you're getting. The maf will throw a code if the ecu sees a either a very high or very low voltage from the maf, indicating a short circuit or a broken circuit. If the maf is operating in a flaky way, then it may be that no code will be thrown.

Can you substitute a maf from a friend's or fellow orger's car?

 

i was having the same hesitation problem after 3,500 the car would not boost it would just go flat. i found two things. my purge valve wasnt operating correctly and i also had a vacuum leak. check by your fpr and make sure all the connectors are intact and and that the hoses are not cut or splitor crimped. check all of them.

 

Great C MAX............. Good to find someone who had the same problem.

Regarding Purge valve, did that throw an ecu code?

Second what is FPR? Third how can I check for a vacuum leak.

I will check the faq to see if any of these questions have already been answered.

 

yes it did eventually. but when mine would act up i could reset it by turning off the car and starting it again. but it didnt throw a code until
i continously drove the code while it hesitated then it finally came on.
so if you cant make it restart, then thats probably not it. i think it only comes on cali spec cars also. as far as your fuel pressure regulator it is located under the throttlebody. its a sort of round ufo looking object with a vacuum hose coming off of it(end of fuel rail). also there will be a adaptor with about four conectors that connect all the vaccum hoses to it. check to make sure all of those hoses are connected properly and there are no leaks. then check the same lines running to the aux fuel pump and aux fuel pressure regulator

 

Now when you say check, you're just refering to a visual check? No voltage/meter readings or anything like that?

I do remember the small adapter that the BOV runs too. If i remember correctly they were all hooked up properly. I will remove them and double check.

I do wonder however how those little tiny tubes could cause the car to have such major hesistation.

 

yes the adapter is where you want to start and check all the hoses to make sure they are on and not crimped or damaged in anyway. those hoses are very important because without the proper vacuum the car cant see boost and you wont get the fuel needed to run properly. also you can spray some starter fluid around the hoses if there is a vacuum leak the car will hesitate.

 

when you took all the piping and what not off...did you put all the hoses and connectors back in place? its possible you forgot to put one back on, or by accident knocked a hose or connector off something else near the piping. just a thought.

--Paul

 

I spend about 30 mins + looking over the engine bay almost everyday for the past two weeks.

As far as i can see everything is connected. Every hose, every sensor, every wire.

I spent my last hour overlooking the engine today. The problem is beyond me.

I am left with two things!

A. Knock Sensor
B. MAF/ECU learn: Because I don't drive the car on the road, it hasn't had time to learn the new MAF. I ran the car for like 25 - 30 mins in park, and i swear it ran a little better. It still had hesistation but i felt a little more powerful! I really can't tell if its just my imagination or if it really got a tiny bit stronger.

I can't drive the car around on the street right now, so warm up in park, and drive around the block is all i can manage.

I won't touch the car again until the knock sensor arrives (hopefully this week). Once the car is streetable I will then ask Paul for some of his time, to help me diagnose and repair the car.

I will definitely need your help on this one bud!

 

Well guys here it goes.

I tested my theory, and in some way shape or form it seems I was right.

I drove the Max to work today, which is about 25 + miles from where I live.

The whole way hoping the ECU would adjust to the new maf or whatever was causing the problem. I figured if it wasn't fixed after a 25 Mile highway trip, then something else was definitely wrong.

Anyway, I drove 25 miles to work and the hesitation did not go away. It continued to die at WOT or above 4k.

I was depressed, and just felt like I was back at square one.

Well to my DELIGHT when I was leaving work, and started up the car BOOOMMMM! The hesitation was GONE!

Now I am ripping and running again (S/C still not running).

Besides running the car the only other thing I did was fill the tank up with gas (Thank was almost on E before)

So its either the system learned the new MAF or I had some bad gas that got burned up on my trip over.

Anyway I am happy right now. Time to get SUPERCHARGED again hehe.

 

Glad your up and running. Did you replace the knock sensor as well?

 

glad everything is ok

 

Yes its running good. No I have not replaced the knock sensor yet. I am still waiting on it to come in the mail. Doesn't look like yoshi(Ebay seller) shipped when he claimed he would.

Hopefully I can work with Requin6 to get the SCer back on this weekend!