somZ2801

iTrader: (8)

o2 sensors cause bad fuel mileage also ck to see if the plunger on your egr valve is working. if it is stuck open or closed thats bad it should move freely . You need to defenitly fix the egr leak that will cause issues with the o2's to read the exhaust wrong and then tell the pcm to dump more fuel in, like 3 other people have pointed out.

The Mighty Texan

iTrader: (4)

Yeah thats been fixed for a while now, wasnt the problem either. After spring break is over im just going to be getting a full scan and it should should enough readings to pinpoint where the problem is, just wanted to get my car running right before then if i could, now its up to the scan and i just gotta wait

zed28camaro

iTrader: (1)

Don't pull the IAC off, itll just cause your car to go to redline.

The Mighty Texan

iTrader: (4)

Well guys, my car isn't going to be able to get into the shop until the earliest opening 2 to 3 weeks from today. I asked the guy what he would advise for diagnosing it and he said the shop will want to start out by fixing whatever is throwing an engine code. Well, secondary air should never cause this correct? I'm assuming now it's the pump and I'm going to pull all of that before I get a frost anyways so I don't want them throwing money there. The engine temperature sensor code has been thrown intermittent (twice) but when checked it seems fine, so maybe the wiring needs checked and or replaced.

I asked him why a full scan wouldn't pinpoint what's wrong and he said te engine codes can throw the engine into a "cold state" causing compensation in areas and this and that, bad sensor management or w/e you will. He said it alot better than me but I understand what he's saying.

What do you guys suggest I do? I hadn't been throwing new parts (engine temp, iac, front o2's yet) considering I'm at 94k maybe I should though. Anyhow, I've tried avoiding spending more than I have to by checking I stead of replacing.

Also, it just seems really weak at idle. Normal rmps but I don't feel or hear the normal kick in the *** strong running v8. Feels more like a tame v6 or something, but that could be a mind thing.

Thanks for all the help so far guys!

ccrook19

the maf is always "calculating air flow" and "engine load", its not just ONLY used for cold starts and WOT...

ccrook19

You can pull of the IAC, just dont mess with the "pintle" and just spray it off with "brake clean"

The Mighty Texan

iTrader: (4)

I replaced the iac valve today and I went for a long enought drive to check, I think it's back to normal now after my first check it showed I had gotten 30.703 mpg. Well see if it stays but I think it's fixed now!

ccrook19

Did u clean up the throttle body while you were at it? i wana say that the # 1 reason these get replaced is because of carbon gets in there gets sticky..

The Mighty Texan

iTrader: (4)

Update: replacing iac didn't do anything, I had miscalculated my mpg by forgetting I had put gas in 1 or 2 times and not recorded it, showing that I had gone far but not according to how much I had put in. Since then, I have taken it into a shop to get it on an engine analyzer and finally see what's going on. However, I used the school's shop because it's cheap and easily accessible, but the senior they put on the job had to leave and won't be back till Tuesday in which I will go find out what he found. The head of the department said they found a misfire. I went ahead and pulled the car out and payed them in advance because at least I can work on it when it's in my driveway, however it will probably go back in on Tuesday.

I looked up causes of misfires and there are multiple reasons. I started by ordering new plug wires like I should have in the first place. Although I tested my stock wires and they seemed good, they need replacing cause my car is at 94k now, and also I did not test them bent just in a natural position. There old and need replacing. Next I've checked the resistance on each injector an there all at 130 ohms, working fine it seems (electronically that is). I want to still check the coils (accurately), get the wires on, and cover the ignition aspect of a misfire, then go from there an see how many things I can knock out before it goes back in. I want to find out what's wrong but I also want to post up what was wrong on here in case anyone has a similar problem and can follow this thread, lots of threads people ask then find the solution and never post it, (what I have found looking through). I've also had a many pm's of people having similar issues so I'm trying to say everything I have been doing so far.

The Mighty Texan

iTrader: (4)

Oh and yes i defiantly cleaned that. I believe somewhere earlier i hopefully stated that, but good point.

The Mighty Texan

iTrader: (4)

Follow up: Although this problem could have been a multitude of these things, eventually it came down the the electrical wiring in either the harness and or the pcm that was causing a misfire and other random things.