ok still trying to resolve lean issue
- Thread starter Alexo1us
- Start date
High Voltage
Member
- Nov 18, 2011
- 462
IllogicTC
Member
- Dec 30, 2013
- 3,452
Alexo1us said:
It certainly shouldn't.
Does the 5.3 have a system to push fresh air into the exhaust like the I6 does? If you can read live data, how does the upstream O2 sensor look? Does it fluctuate between 0.1 and 0.9 volts, or does it stay bottom lined at <=0.1?
Texan
Member
- Jan 14, 2014
- 622
I do not have the V8, but wonder what you did to check for vacuum leak.
I am going to include a link to your original post. Did you use propane
or carb cleaner to check for intake manifold leak?
http://gmtnation.com/f26/p0171-4-oh-boy-fun-starts-9655/
I am going to include a link to your original post. Did you use propane
or carb cleaner to check for intake manifold leak?
http://gmtnation.com/f26/p0171-4-oh-boy-fun-starts-9655/
- Feb 1, 2014
- 38
yes my sensors operate correctly.
For leak i checked with propane had some handy.
I would expect it to rev abit and some change in lean to more normal or rich even depending on how bad leak.
plugs are fine, and since its both sides and i dont really think fuel is issue i should do test.
changing gaskets seem easy enough book is 1.5 to 2 so i should be able to get in few hrs
For leak i checked with propane had some handy.
I would expect it to rev abit and some change in lean to more normal or rich even depending on how bad leak.
plugs are fine, and since its both sides and i dont really think fuel is issue i should do test.
changing gaskets seem easy enough book is 1.5 to 2 so i should be able to get in few hrs
IllogicTC
Member
- Dec 30, 2013
- 3,452
What does the MAP sensor read? I've found a thread in another forum where the guy says he's at around sea level, and 10.6 or so is low for his area. It adjusts with altitude of course, what that sensor reads.
Have you tried examining closely under the hood and listening for any sort of hissing sound? At this rate my suggestion would be to go with what one respondent said: hook it up to a smoke machine and block off the air intake tube. If nothing shows up... use better gas. The guy took it to a shop, did all the tests including smoke machine, and ended up telling him to switch to a Top Tier brand. They showed him a sample of the gas in the tank, looked like "red kool aid." It may just be their dyes but it generally doesn't look like that.
He never explains whether or not he followed this instruction before going on to say he thinks the shop was doing the job half-hearted, so I have no idea if the solution was ever found. I'll look around more tomorrow, it's my bed time.
Have you tried examining closely under the hood and listening for any sort of hissing sound? At this rate my suggestion would be to go with what one respondent said: hook it up to a smoke machine and block off the air intake tube. If nothing shows up... use better gas. The guy took it to a shop, did all the tests including smoke machine, and ended up telling him to switch to a Top Tier brand. They showed him a sample of the gas in the tank, looked like "red kool aid." It may just be their dyes but it generally doesn't look like that.
He never explains whether or not he followed this instruction before going on to say he thinks the shop was doing the job half-hearted, so I have no idea if the solution was ever found. I'll look around more tomorrow, it's my bed time.
High Voltage
Member
- Nov 18, 2011
- 462
- Feb 1, 2014
- 38
I have been working on my lean issue haven't changed the gaskets yet. I took off the tb found air leak at top dont think the shade tree wannabe took the time to make sure he had it flat cleaned up the Mass air and tb.
I reset pcm and checked it got it much better it runs around +9 at idle and just off idle drops down to almost 0 stays there til idle then slowing goes up to + 9 since the PCM is still learning I may see the drop again at idle we best news no more codes. I may try running a torque wrench around the intake to make sure its still tight but I suspect now it may have been tb not set right and some bad gas put some ultra in made difference.
anythoughts ??
- Feb 1, 2014
- 38
for sure the tb was a problem but still at idle ltft is high but drops when movin to near 0, all the hoses look fine the map sensor feels bit loose but dont think its leaking. i know it still has bit learning to do maby she will settle next day or 2. What normal for 5.3?
For example i know my wifes 3.5 v6 idle usually around +1 with stft near 0. But now i need to look at logs again but in typing i think with the stft it would be dam near 0 which is good thing.
For example i know my wifes 3.5 v6 idle usually around +1 with stft near 0. But now i need to look at logs again but in typing i think with the stft it would be dam near 0 which is good thing.
- Feb 1, 2014
- 38
ok so i got her working alot better going for etest no codes and all test passed so shouldnt be issue
but im going to change intake gaskets this weekend.
should i go with felpro set of gaskets or new GM style? also i have read u should never reuse the bolts i have originals installed currently. should i get new ones or is there a better replacement?
thanx for all the insight in this issue u guys rock...
but im going to change intake gaskets this weekend.
should i go with felpro set of gaskets or new GM style? also i have read u should never reuse the bolts i have originals installed currently. should i get new ones or is there a better replacement?
thanx for all the insight in this issue u guys rock...
I've never ever read that about intake manifold bolts. Are you sure?Alexo1us said:
Don't re-use exhaust manifold and head bolts.
- Feb 1, 2014
- 38
The_Roadie said:I've never ever read that about intake manifold bolts. Are you sure?
Don't re-use exhaust manifold and head bolts.
i would never reuse head bolts going that far into engine not too be counter productive imlo.
the bolts have a rubber and sleave designed to compress during torque process makes sense to replace them I will try and refind the tsb i read on this..
heres link http://www.autorepairinstructions.com/?p=224
Thanx