MAXIN

iTrader: (5)

Im getting horrible hesitation in upper rpms. (not sure if this is 'missing' or not)

I had some debre in the MAF that I blew out with a can of compressed air. (cleared the MAF code) But I did drive home that day (about 15-20 blocks) with the MAF unplugged as it wouldnt run with the bad MAF.

After I fixed the MAF problem I got codes 0210 (front bank lean) and 0304 Knock sensor and this hesitation/(missing?) after 4000 rpms. Cleared codes again, havent got back the 0210 but the 0304 came back again.


Knock sensor resistance is about 5 M ohms. Vacuum seems ok, about 22hg, what would a reading be if there is a vacuum leak? Fuel psi is normal.

Car idles normal, and drives normal under low to medium throttle and in the lower rpms.

Any this else I should check before replacing the knock sensor?

IceY2K1

iTrader: (3)

By hesitation do you mean it stops accelerating, ie bogs?

If so, does it begin to accelerate as you back off the throttle slowly?

MAXIN

iTrader: (5)

Yea, I guess you can call it bog.... I can drive the car at part throttle and not notice a thing - moderate to full throttle is when it bogs.

I just tried something else, at idle, in neutral, if I rev the car but keep it under 4000 rpms it revs fine. Once I try to pump the peddle (release and hit it again) at any rpm above 4000 it 'studders' on a slow climb to redline. Am I describing 'missing?'


I was told me to check my coils. (any one have a howto link?)

IceY2K1

iTrader: (3)

I could be WAY way off here, but if you drive and floor it and it "bogs", then start slowly backing off the throttle and it picks up immediately, it could be a sign of a weak fuel pump or maybe a clogged fuel filter/injectors.

DonSupreme

iTrader: (1)

Maxim,
What you described is EXACTLY what my car is doing. The only thing is my supercharger belt is not hooked up right now. Chances are if i hooked the belt back up I would probably still have this problem.

Have you found a solution to this problem yet?

I used to get the MAF code, and I replaced the MAF and cleared the code. Now I am getting the 0304 code (Knock Sensor).

What else have you tried since making this post?

IceY2K1

iTrader: (3)

Could it be the SC belt slipping maybe?

DonSupreme

iTrader: (1)

Well in my case my supercharger belt is totally disconnected. I am running on stock belts for the time being. I was wondering if the SC piping was choking the system, but if his supercharger is still running with hesistation then maybe I should be looking else where?

Have faulty knock sensors been known to cause hesistation? If so I have never seen that mentioned before.

IceY2K1

iTrader: (3)

So, your SC is still installed and the engine is drawing through a non-turning SC?

DonSupreme

iTrader: (1)

Thats is correct......... Why the suprised face? Is that super bad or something? I know the engine can't get the air it wants, but I really need to know if it could choke the engine that badly!

IceY2K1

iTrader: (3)

Honestly, I don't know.

However, I can't imagine that's not a *HUGE* restriction in the intake causing major pressure drop. I mean in a turbo system, the air filter alone can be a 0.5-1.0+psi pressure loss, so what would that mean for a non-turning or at least slowly turning SC compressor? I'd say at least 10% less air is entering the engine.

I'd say it's not "bad", but you're probably missing some serious HP over stock levels.

I know it's temporary, but I'd guess that's why you're feeling the hesitation and don't go chasing other gremlins until you get that removed.

Why don't you just install the stock intake?

iansw

iTrader: (7)

I ran for 3 months drawing through the SC and didn't notice any ill effect.

Car ran fine - albeit way slower than I'm used to.

DonSupreme

iTrader: (1)

Yes i am 100% sure its not the piping. I took all the piping off up to the MAF and it still had major hesistation!!!

Isn't there some kind of temporary way to trick the system that the knock sensor is working? Some kind of resistor or something? I am going to check the FAQs. Hopefully i can find that information there.

MAXIN

iTrader: (5)

No solution yet. So far I checked the front bank plugs (good), swapped out front back coilpacks (with spare used packs), tested them with some methods I found, (test method worked reverse for me) and did the 'listen' test on the injectors (good). I also ran the car down to E and put a fuel system cleaner in. I did the knock sensor bypass, cleared the knock sensor code but still hesitates/studders horribly in upper rpm range. Still gotta check the rear bank plugs/injectors/coilpacks, and the connectors for all the coilpacks/injectors.

I just wish the ECU would spit out a code or something, with the knock sensor bypass I get 0505, and the problem remains.

DonSupreme

iTrader: (1)

Thank you for posting your progress. I ordered a replacement knock sensor, but i fear it will not fix my problem....

I am suprised that no one else on the .org has experienced this problem.

Please keep me informed on your progress.