KGSloan

ok, here's the deal. i went to the bank earlier and the car was running fine on the way there. i then sat in the bank line for a few minutes and then when i left the car started missing. at first it just felt like a fouled plug, but then it kept getting worse and worse. by the time i got home (about 1 mile away) the car was running horrible! it seems like it wasn't firing any of the cylinders at the right time at all. it was running really rough, sputtering bad, and was way down on power.

what do you guys think this is and how do i go about fixing it? it seems to me like the cam or crank sensor maybe went out??? i don't really know what kind of sensors we have on the motor or where they are. i'm pretty good mechanically. i put the cam in myself and have done all of my other car work myself so i feel confident i can fix it, i just don't know what i need to do or where to start. thanks for you help

minivette

SES light? if so scan it.

KGSloan

nope, no ses light.

Pro Stock John

iTrader: (34)

What springs? Could be a broken valvespring.

KGSloan

i just pulled off the valve covers and all the springs and rockers look fine. the are rev 1116's. what else mechanically could it be or should i check? if there isn't anything else mechanical, is it the cam position sensor?? it didn't throw an SES code on the drive home (although it was short). maybe they turned the code off when i got my tune done ? although the SES light did come on for a little while at the track when i turned on my high fans, so i don't think they just turned the light completely off. where is this sensor and how do you go about changing it?

MOBE

Sounds like exactly what my car is doing right now. I havn't figured out whats wrong yet. I too have REV 1116s.

KGSloan

keep me posted on what you find out

soundengineer

iTrader: (16)

sounds to me like maybe the knock sensor is going bad...it would cause some serious timing issues and wouldn't necessarily throw any codes....and with a different cam the pcm might not be to good at correcting it??? have you gone to a shop and had them do a diagnostic??? maybe a buddy with autotap??

MOBE

KG,

Get it auto tapped and see whats happening. Mine wasn't throwing any codes either, but they (tuners) typically take out the P0300 code (misfire code) for larger cams. After I ran atap, I found out that cyl. #4 was missing like crazy.

This all happened to me last Thursday on my way home from work, under normal driving conditions. I havn't been getting on it at all lately, or missed any shifts ever. I baby my car. It just happened for no apparent reason.

I have checked all the obvious... plug wires, changed out plugs, swapped around coil packs, checked for broken spring(s), bad rocker arm... I'm gonna check the springs again, do a compression test, and a leakdown test on #4.

When I pulled the plugs out to swap them, the #4 plug was black. The others were not. After putting new plugs in, I took it for a spin around the block to see if that helped. It did not. I pulled the new plug out, and it was already black, after 5 minutes of driving it. This leads me to believe that the exhaust valve is not opening.

Blue02Ws6

iTrader: (3)

Mine did that too and it was a bad ground on my O2 sensor wires knocking out the ENGSENSOR fuse under the hood. It is a 20amp fuse and it will screw alot of crap up. Check that first, and if that isn't the prob I don't know what it is.

KGSloan

i don't have autotap or access to it. can i goto the dealer to have the computer scaned to figure out what it is? will it show what i need to know? will they charge me an arm and a leg? i've been wanting to get autotap for a while now and was seriously considering it recently. maybe i should just get that so i can figure it out and have you guys help me out with it. what do you think

MOBE

Since its not throwing any codes, the dealer will most likely tell you there is nothing wrong. You really need to use atap or efi live to log it while you are driving. My car idles fine, but once its under load, it runs like ***.

Blue02Ws6

iTrader: (3)

Have ya'll checked that fuse?

Pro Stock John

iTrader: (34)

I would check that fuse and other fuses.

I'm thinking also it could be a burned 02 sensor wire.

MOBE

I'll check that fuse, but my situation seems to be focused on the #4 cylinder only.

Blue02Ws6

iTrader: (3)

Yeah, that is what I thought also, mine was burned by my headers and my car act like it was haunted....

witout post count, my opinion means nothing though...lol

KGSloan

i checked that fuse, it was fine. blue02ws6, your opinion counts and is much appreciated. i checked that fuse before psj said anything about the o2 wires. i havn't ran over the entire wire yet because i don't feel like going outside and doing anything on it right now (it's hot here).

mobe, my car seems to act the same. it idles fine (not right, but ok) and then as soon as i give it any gas it won't hardly run.

i'll check the o2 sensor wires tomorow just to make sure that's not it, although i havn't touched them since i put the headers on 8 months ago and i havn't had any problems so that seems wierd to me, but we'll see.

i'm going to go ahead and get autotap. i've been meaning to get it for a little while and now i really see the benifit of it.

anyone else's opinion is welcome

MOBE

SOLVED MY PROBLEM!

Broken spring on #4 exhaust valve. I suggest you check your REV springs.

KGSloan

i checked the valve springs allready. they all look fine. was it the outside spring that was broken or the inside or both?

MOBE

The outside spring. The inner spring is okay, and appears to have saved my engine.

I checked mine once befor too. But I obviously missed it the first time.

Did you take the rockers off when you checked?