marlyman

starting a new post /continueing old thread. Running lean wont smog - I've done tons of research, getting codes 41 & 91. So i did base idle reset, so idles good/fine, set tps to like 8.5, bought new 02s(both), new egr valve, checked / ran new vacuum lines, checked 02s ground an actually ran an entire new ground wire from #49 on harness to the back of head tested resistance an i get 5.5ohms (supposed to be under 5ohms?) new act an coolant temp sensor guess im about to check fuel pressure but man i just cant seem to figure this out!?! any input??

mattdel

crack in the intake tube past the maf, intake gasket leak, TB gasket leak, clogged injectors, clogged fuel filter, bad fuel pump

marlyman

Ok cool i already got a new fuel pump and fuel filter so i might aswell throw them on intake piping is a o k so ill process of elimination..i was on sbftech an someone wrote how they took vacuum line off of the fpr an it made the motor run better well i pulled the vacuum off mine an it didnt change anything that i could tell or hear..would that be an issue? i mean its definetly getting vacuum from the line.. fuel pressure issue was my first thought an i got this bbk fpr but smog guy says he wouldnt pass it with aftermarket adjustable fpr..bah if mines bad ill just go buy stock new one..

marlyman

would an exhaust leak at the headers give me 41 & 91? pretty sure got a mean exhaust leak on the pass side header just got nice new gaskets an bout to switch em out when its cooled off..i got some carb cleaner an tried to find vacuum leaks / leaks around intake/throttlebody/maf but i get nothing and i just put in new fuel filter old one wasnt that bad..that fuel pressure regulator thing is kinda bugging me tho beause when i pulled off the vacuum line nothing changed doesnt that mean somethin is obviously wrong?

mattdel

By ear, you probably wouldn't notice a change in anything by taking the vacuum off the regulator. In any case I'd rather be sure, though. You can hookup a manual vacuum pump to it and see if it will hold a vacuum, this will tell you whether the regulator is working or not.

With the exhaust leak, I'd expect to only see 1 code if only 1 side was leaking, but it's not entirely impossible to have both.

Fix the simple stuff like the exhaust leak and check the regulator, then go from there.

marlyman

Ok so i tightened up the exhaust everywhere so no leaks been messin around with base idle reset to get that perfect an messin wit my tps sensor to get that dialed in how i want it..think im running like .775 on tps ive read 7-9 is ok but i also read that people want it bout .9 but when i put it to that when i give any throttle it takes forever to drop back to an idle...while doin the base idle reset i think my iac started whining or whistling could that mean it needs to be replaced ? would the iac cause a lean condition? and since i dont have a vucumm or anything to give the fpr vacuum i had got this bbk adjustable fpr an ima right now go put it on to see if i can balance out this damn lean...thought i had blown head gasket or rings but did compression all where fine an held the compression good...iac tho?

mattdel

Contrary to popular belief, the theory of "setting" your TPS is impossible. The computer automatically adjusts its upper-end expected values based on where the closed throttle position voltage is, giving you no benefit. Joel5.0 is the guy with the crazy in-depth knowledge of that stuff. He mod's sbftech.com. Check it out if you wanna get intricate knowledge. Basically, if your closed position is 0.775, your wide open position would be 4.775. If you go to 0.9, open would be 4.9. Makes no difference.

IAC could cause a lean condition, but it would be rather temporary. The computer, again, would adjust itself quickly to the problem and most likely end up a bit rich.

#1 culprit, by the way, of engines that take forever to return to idle: vacuum leaks.

marlyman

uhg ok well, got new iac but did not change anything and im surging a bit at idle so..i got some new vaccuum lines just to make sure an i have a routing diagram so ill jus do that then ima do base idle reset for last time make sure everythings good... everything has been passing the emissions except for my nox where high got a new egr valve an it lowerred the nox a bit but just not enough 41 an 91 are ego sensor failing to switch..uhg still havent done the fpr thing yet i mean is that a likely reason for lean condition i mean my fpr looks pretty old..i should jsut put the bbk one in to see wtf...

RAP66

Check your TAB & TAD sensors on the passenger side shock tower.

I didnt even know these existed until I swapped the motor, when I pulled them both were cracked causing a pretty large vacuum leak. Had I found this before the engine swap, it could have save me alot of headaches.

marlyman

Yeah i know of them : ) an u r probably right they im sure need replacing because i've tried everything else lol like everything!! uhg just put in new stock fpr an nothin no change uhg new iac nothin no change base timing reset no change fixed exhaust leaks no change made sure tps sensor .7-.9 no changedid compression check all good pulled valve covers off an made sure rocker assembly was at proper torque spec an nothing!@#$ uhg i ran a whole new ground for the 02s nothing even put all new vacuum lines an still!@#$@ so must be tad / tab sensors...im lookin right now an autozone/kragen dont have them where would i go to get new ones???