Tupp

I hope I put this in the right place. If I made a mistake please do move or let me know where it should go…

so I just picked up a 2000 Z28 LS1 M6 car. It has 146001 miles when I picked it up. From what I can tell it has a large air element instead of the box and a flow master exhaust. Other than that it appears very stock.

when I drive it the car hesitates and stutters between 2000-3000 rpm. Once I get over that it’s fine.

it appears to stutter using heavy throttle and light throttle.

i intend on doing new plugs, wires, fluids and such just as a tune up/precaution but is there other things I should be worried about?

i searched “Boggs” “Stutters” “Heaitation” but yielded no results except one guy saying he cleaned his MAF for a completely different issue, which is a good idea either way.

thanks in advance.

jdperk-86elco

It sounds to me like a fuel issue. I suggest the following:
- Purchase BG-44K fuel cleaner to clean the injectors.
- Either try and clean the MAF sensor with a special cleaner or replace it with a new one. Don't buy a cheap Chinese version buy an OEM it will be worth the money. Most of the time, the cheap versions cause other issues you will be fighting.
- Check your fuel pressure. If it is below 58 PSI (if I am not mistaken), then it could be a weak fuel pump.
- Change any fuel filter.
- Ensure your air cleaner is not clogged by changing or cleaning the filter.
- It could be the transmission slipping. One easy fix that works often is by dropping the transmission pan and changing the filter and new fluid. One would be surprised how this simple filter and fluid change does wonders for a transmission.

You should get a scanner and check for any codes. The codes will point you in the right direction. You can borrow a scanner from a parts store to read the codes.

Good luck, I hope these suggestions help.

Tupp

All very good info. I will check it all.

It’s a manual car so idk about it slipping. The clutch holds and doesn’t appear to slip.

i have a cheap AutoZone kind of code puller. Would that provide raw fuel pressure data or do I have to hook up a gauge and stick it on the windshield?

Biebs

Air filter problem!!

Does it have a large Oiled air filter Like a K&N style?? Ditch that $hit!!!
Will put oil on the MaP sensor.

You can get a fuel pressure gauge that mounts on the fuel rail under the hood should show 58 to 60 PSI at idle.

Tupp

It has this with the Volant badging

01CamaroSSTx

iTrader: (3)

Sharp looking car and I'm digging the stripes!

Could very well be a fueling issue, bad gas and/or clogged injectors. Start it up in the dark and look closely at the wires to see if you notice any arcing indicating a bad plug wire. Clean up of the air filter and MAF sensor, PCV valve and add a fresh set of plugs and wires.

Tupp

So I added the BG-44K fuel cleaner. The car was on 1/4 tank when I added it and I filled it up with good ol 93 octane.

i bought the fuel filter and a legit MAF cleaner spray.

i haven’t been able to do the MAF cleaning or fuel filter but I’ll check back when I have that handled.

i also ordered a cheapo fuel pressure gauge.

thanks everyone so far

SteveC

Not if you oil it properly, You wash the filter from the top down, and oil from the bottom up applying very little oil on the pleats only.
I have been using this method for over 20 years with an occasional MAF cleaning with no problems whatsoever. My MAF has never been gunked up. Love your SOM car

Tupp

So I put the fuel pressure gauge on the rail (haven’t done a thing but the fuel system treatment) with just the key on , NOT running, and I got 52lbs but the fitting was kinda leaking.

im gonna find another gauge that doesn’t leak and try again.

does the car need to be running or should it have 57lbs at all times with the key on??

Tupp

UPDATE :

so my gauge came and straight away I checked. I have perfect fuel pressure.

Since I bought it as a summer car and there is salt and yuck out I’m not gonna be able to drive it enough to work the fuel system treatment through. Unfortunately I’ll have to wait till it warms up outside to let that run its course.

hopefully it’s a mix of bad gas, fuel filter will be changed and clean the MAF.

does anyone have any other potential things I can check out in the car for that hesitation?

01CamaroSSTx

iTrader: (3)

It should maintain 58psi with running engine. Bad or dirty injectors, fouling spark plugs and burnt wires will cause rough idle and a loss of power.

Tupp

Car runs starts up great all the time. Idles perfectly. Drives well under light throttle.

under load between like 2250-3250 RPM it hesitates. Once it’s over that it’s fine.

when the car is cold it doesn’t have the hesitation.

i think it’s the injectors needing cleaning or the MAF.

Tupp

*** Small Update ***

so I’ve run about a half tank through the car with the fuel system cleaner. It’s kinda better.

i confirmed I have proper fuel pressure and the fuel filter is changed.

I have not cleaned the MAF because it’s still cold and the plastic is still to cold and brittle to remove.


however… when the car is cold it doesn’t have the hesitation anymore. When it warms up it does hesitate under lighter throttle but under full throttle it is fine.

does that further make it look like it’s the MAF or could it be something else?

Tupp

New plugs, new wires, cleaned MAF (boy was it dirty) and new fuel filter.

under moderate to full acceleration there is no hesitation or stutters but under light throttle acceleration it does still hesitate.

any other ideas without getting crazy.

Y2K_Frenzy

Small vacuum leak maybe that is “over come” when there’s enough RPM. It idles steady when the motor is warm?
If the MAF was real dirty then the TB will be as well. Probably not the fix to your problem but cleaning it wouldn’t be a bad idea if you haven’t.

Tupp

Any guesses to where I might look for this vacuum leak?

Edit : pretty bone stock minus the. Vollant cone intake and axel back exhaust.

sjsingle1

iTrader: (1)

does your car still have the stock PCV system ? the hoses from the drivers side valve cover to the pass side rear valve cover....then to the front of the car leading to to the PCV valve itself to the manifold? as old as it is and if it has never been replaced...its a VACUUM LEAKFEST
get a new hose or convert to LS6 valley cover

Y2K_Frenzy

I think I’d smoke test it first. Then I’d probably find a way to splice new hose if I could before replacing the entire hose and or getting as financially and physically involved with a new valley cover. Mods are cool but at the end of the day it’s an expensive and hard way to fix a vacuum leak.

Tupp

I’ll dig in to it.

i don’t own a smoke testing machine. So I’ll have to look in to that too.

i appreciate the help.

wssix99

iTrader: (5)

I'd stay on this a bit longer. Your symptoms are classic dirty MAF and by the looks of the bangles your P.O. installed under your snot, you must have a lot of build up.

Many of us have been through this before and a simple spray wasn't enough to get the MAF clean. If you disassemble the MAF, you can us a magnifier to see if any black streaks are still on the wires. IF you do this, you need to be super careful as the screens protect the wires. They are extremely fragile and if you break one, then you'll need a new MAF. I ended up having to clean mine with a Q-tip, but that is definitely recommended due to the risk - but others have done it successfully. (with a light touch) You'll want to clean until all the black deposits are off the sensor wires.

When this problem was first reported in the early 2000's, GM also claimed that the O2 sensors were getting fouled. I have never seen a technical explanation why this would happen, but I also changed mine under the advise of a dealer. (I took mine in for a warranty complaint and they gave me the finger since I put a K&N filter on the car - but they shared "advice" for free.) The combination of a deep MAF cleaning and new O2 sensors (and going back to a paper air filter) made the problem go away for good.

If you can really tell the difference between a paper filter and an oiled one, you are a better person than I am. Personally, I think the oil filters should be for sale on the shelf next to snake oil. The best compromise I've seen on this site is to run a paper air filter and then put a K&N sticker on the bumper so everyone thinks that you have an expensive air filter. (No fuss that way.)