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Old 07-24-2014, 10:42 PM   #1
chevyman70
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5.3l 4l60e issues NEED HELP!

I started to have transmission issues (recently rebuild), late downshift almost coming to a stop. Now, it shuffles out of lock-up on 4th gear between 40-50mph. Took it to the transmission guy, and he replaced the valve body and solenoids, but to no avail. In addition to the transmission problems, I started getting p0171, and p0174. Long Trim is at 25%, even during idle. Short trim isolates between 0-6%. O2s isolate between .100 - 800. MAF is a bit erratic when I graph it on the actron reader. When I to read the hertz on the MAF, multimeter reads 0.00. reference voltage is 2.2 during idle. There is 12v going to the MAF, as well as good ground. I replaced the intake gasket, but the intake runners seem warped. I'll add it pictures. With new intake gaskets, the problem did not improve. Fuel pump read 52psi, jumps up to 60 when I disconnect the vacuum regulator. Replaced fuel filter.
Please take a look at the pictures and let me know what you think of the intake manifold. The intake runners have a dip near the bolt opening. All this is happening at the same time. I need your help!
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Old 07-25-2014, 01:08 AM   #2
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Re: 5.3l 4l60e issues NEED HELP!

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Now, it shuffles out of lock-up on 4th gear between 40-50mph. Took it to the transmission guy, and he replaced the valve body and solenoids, but to no avail.

lockup related issues have multiple causes, but an easy one to check is that the brake switch is functioning and wired properly. depending on your cam, you may or may not be hitting the Misfire counter, and causing the ecm to disallow lockup. That part is a function of the tune, and you can't do much mechanically.

In addition to the transmission problems, I started getting p0171, and p0174. Long Trim is at 25%, even during idle. Short trim isolates between 0-6%. O2s isolate between .100 - 800. MAF is a bit erratic when I graph it on the actron reader. When I to read the hertz on the MAF, multimeter reads 0.00. reference voltage is 2.2 during idle.

This makes me think either the MAF is junk, mounted improperly, or has a damaged/loose wire. If you have a K&N type air cleaner, and oiled it, you may have also gunked up the maf. Unplug it, clean it with MAF spray and check its wiring harness. When you toss it back in, make sure its got a relatively straight shot to work on, and that its mounted in the upper 1/3 of the pipe. Its also possible there is a tune issue. At 0hz it would me MAF failure, which puts the engine into speed density using VE tables. A well tuned ve table should still idle and run OK without maf input.


I replaced the intake gasket, but the intake runners seem warped. I'll add it pictures. With new intake gaskets, the problem did not improve. Fuel pump read 52psi, jumps up to 60 when I disconnect the vacuum regulator. Replaced fuel filter.

Regulated pressure should be right at about 58psi, which is about what your getting when you unplug the vacuum line. That tells me the regulator is probably ok, but the vacuum source is not. Either your leaking out of the runners, of the plastic intake itself is cracked (or there is a tiny leak somewhere else that we aren't looking at). Have you tried carb-spraying for leaks while its running?
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Old 07-25-2014, 02:51 AM   #3
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Re: 5.3l 4l60e issues NEED HELP!

Originally Posted by chevyman70
Now, it shuffles out of lock-up on 4th gear between 40-50mph. Took it to the transmission guy, and he replaced the valve body and solenoids, but to no avail.

lockup related issues have multiple causes, but an easy one to check is that the brake switch is functioning and wired properly. depending on your cam, you may or may not be hitting the Misfire counter, and causing the ecm to disallow lockup. That part is a function of the tune, and you can't do much mechanically.

thank you for responding!
I did check brake switch to see if it's working properly, and it is. Bank 1 seems to have a miss, and I am able to hear it on the exhaust pipe. Perhaps it's due to the lean condition. I check wires, coils, plugs, power, ground, and they check out okay.


In addition to the transmission problems, I started getting p0171, and p0174. Long Trim is at 25%, even during idle. Short trim isolates between 0-6%. O2s isolate between .100 - 800. MAF is a bit erratic when I graph it on the actron reader. When I to read the hertz on the MAF, multimeter reads 0.00. reference voltage is 2.2 during idle.

This makes me think either the MAF is junk, mounted improperly, or has a damaged/loose wire. If you have a K&N type air cleaner, and oiled it, you may have also gunked up the maf. Unplug it, clean it with MAF spray and check its wiring harness. When you toss it back in, make sure its got a relatively straight shot to work on, and that its mounted in the upper 1/3 of the pipe. Its also possible there is a tune issue. At 0hz it would me MAF failure, which puts the engine into speed density using VE tables. A well tuned ve table should still idle and run OK without maf input.
I cleaned the maf, and still have the same result. I briefly got p0102 but cleared.

I replaced the intake gasket, but the intake runners seem warped. I'll add it pictures. With new intake gaskets, the problem did not improve. Fuel pump read 52psi, jumps up to 60 when I disconnect the vacuum regulator. Replaced fuel filter.

Regulated pressure should be right at about 58psi, which is about what your getting when you unplug the vacuum line. That tells me the regulator is probably ok, but the vacuum source is not. Either your leaking out of the runners, of the plastic intake itself is cracked (or there is a tiny leak somewhere else that we aren't looking at). Have you tried carb-spraying for leaks while its running?

I sprayed carb-cleaner around each of the ports and no rpm change. The intake ports have a dip next to the bolts. I am not sure if this is normal. Hopefully is viewable on the pics.
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Old 07-25-2014, 10:46 AM   #4
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Re: 5.3l 4l60e issues NEED HELP!

that dip is a pretty normal mold defect, should seal just fine with the proper gasket
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Old 07-25-2014, 11:18 AM   #5
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Re: 5.3l 4l60e issues NEED HELP!

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that dip is a pretty normal mold defect, should seal just fine with the proper gasket
So, if a new gasket is not fixing the lean condition, then is it the MAF?
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Old 07-25-2014, 11:21 AM   #6
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Re: 5.3l 4l60e issues NEED HELP!

could be MAF but it could also be something in your tune.

will it idle at +/- 5 with the MAF unplugged?
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Old 07-25-2014, 11:51 AM   #7
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Re: 5.3l 4l60e issues NEED HELP!

could be MAF but it could also be something in your tune.

will it idle at +/- 5 with the MAF unplugged?

I had the PCM reflashed to see if it had anything to do with the tranny shifting erratically. When I unplugg the MAF, it idles okay. What do you mean +\- 5?
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Old 07-25-2014, 12:52 PM   #8
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Re: 5.3l 4l60e issues NEED HELP!

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could be MAF but it could also be something in your tune.

will it idle at +/- 5 with the MAF unplugged?

I had the PCM reflashed to see if it had anything to do with the tranny shifting erratically. When I unplugg the MAF, it idles okay. What do you mean +\- 5?
LTFT %

If it idles better unplugged, that means the VE tables being used are at least "ok". That points back in the direction of the MAF or its related wiring. While its possible there is a tune issue, I don't want to suggest that if there is a diagnosable MAF failure.

If I need to test a MAF, I call in a favor at the parts store and grab another brand new maf. Clear codes (or pull battery), connect the new maf, let it idle up and see if any of the problems self-clear. If so, you can either keep the new MAF, or return it and find a junkyard/used replacement. A little ghetto, but works when you don't have easy access to a salvage yard on a weekend.
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Old 07-25-2014, 08:27 PM   #9
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Re: 5.3l 4l60e issues NEED HELP!

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LTFT %

If it idles better unplugged, that means the VE tables being used are at least "ok". That points back in the direction of the MAF or its related wiring. While its possible there is a tune issue, I don't want to suggest that if there is a diagnosable MAF failure.

If I need to test a MAF, I call in a favor at the parts store and grab another brand new maf. Clear codes (or pull battery), connect the new maf, let it idle up and see if any of the problems self-clear. If so, you can either keep the new MAF, or return it and find a junkyard/used replacement. A little ghetto, but works when you don't have easy access to a salvage yard on a weekend.
So I disconnected the MAF, and the LTFT% went from 25% to 8%. I drove it around and it ran just as if it was plugged. The LTFT% isolated from 8% to 22% depending on how I was driving. STFT% isolated from 0% to 6%. Once I plugged it back on, it jump to 25%. Sprayed carb cleaner all around and no RPM increase. The MIL light did not turn-on while it was unplugged.
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Old 07-25-2014, 10:56 PM   #10
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Re: 5.3l 4l60e issues NEED HELP!

did you do your harness yourself? might need to trace out the maf wires to the pins.
i did like Jay said when I was hunting down a ltft problem. tried a new maf from autozone it didnt fix it and they let me return it.
mine turned out to be bad injectors though.
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Old 07-26-2014, 01:32 AM   #11
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Re: 5.3l 4l60e issues NEED HELP!

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did you do your harness yourself? might need to trace out the maf wires to the pins.
i did like Jay said when I was hunting down a ltft problem. tried a new maf from autozone it didnt fix it and they let me return it.
mine turned out to be bad injectors though.

The MAF is not jumpy after I cleaned the MAF. It is stable during idle. However, I still get P0174 and P0171. Now, I am getting a p0116 code. I did do my own harness, and I did check the wires and they turned out okay. I drove it today to see what it does. I noticed the MAF would go from reading 10lb/g at 2300 rpms to 1.3lb/g still at same RPMs. I also noticed ignition timing go from 45 degrees, to 20 degrees at same 2300 RPMs. I also rev the engine to 3000 rpms, and the ignition timing went from 50 degrees to 34, 20, 40 degrees at same RPMs. I believe I saw the timing go as low as -45 during deceleration. I didn't pay much attention since I was driving, and I thought I must have read it wrong. I also drove the truck in 3rd gear to see if the shuffling between 40-50 mph would stop, and it did the same thing. I noticed the rpms would fluctuate from 1600 to 1800 rpms at same speed. I checked the tps and the MAF to see if it fluctuated when this happened and it did not. Also bank 1 seems to have a miss during the RPM range 1500-2000, well really anything above 1500.
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Old 07-26-2014, 02:04 AM   #12
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Re: 5.3l 4l60e issues NEED HELP!

I also noticed that the intake runners has a lot of oil in them. The gaskets were wet as well. Is it sucking oil?
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Old 07-26-2014, 02:29 AM   #13
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Re: 5.3l 4l60e issues NEED HELP!

Ok, we gotta take a step back here. We are no longer dealing with 1 small problem, but instead a handful of stuff stacked up. Your problems are confusing each other, we gotta try to eliminate one to see if the others change.

I still haven't seen you try a new maf yet, its plug-n-play, in 5 minutes you can put one in and see how much changes. We can't keep putting ideas out if you don't go through the process w/ us.

The timing thing is scaring me, so please put as little mileage on as you can. 45 degrees + is enough to pop your motor VERY quickly. If you see that kinda timing, your risking massive detonation. LS motors, especially truck motors, NEVER want more than MAYBE 32* (this is pertaining to basic swaps, but even specialty stuff doesn't want that much timing). That much timing WILL cause misfire and knock, and that is probably why the trans is shuffling and ignoring lockup. The p0116 is coolant temp, which means either a problem with the temp circuit, or overheating.

There may be a much greater problem in either the tune or the harness, but there is too much going on to pinpoint it. Get a new MAF to test that so we can rule it out. Can your scanner read misfire and knock counts? if so, tell me what it logs.

Who did the tune for this again?
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Old 07-26-2014, 11:53 AM   #14
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Re: 5.3l 4l60e issues NEED HELP!

to answer your oil in the intake question, these motors seem like they pull a lot of oil through the PCV into the intake. I had a bunch of oil in mine and ended up adding a catch can.

also agree with brew. establish a baseline with a good MAF.

the timing jumping around. i'll see +45* at light cruise..but generally 22 at idle and 32 at WOT

I would also double check your grounds to the back of the head, and head to frame or body. I ended up with 3 engine to frame grounds before all my weird little issues stopped.
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Old 07-26-2014, 12:17 PM   #15
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Re: 5.3l 4l60e issues NEED HELP!

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the timing jumping around. i'll see +45* at light cruise..but generally 22 at idle and 32 at WOT
Not to get off the OP's topic, but I'm curious in your case; was this light-throttle cruise with light/med load? Thats one of the places in your tune thats the most likely to be erratic due to its potential to knock. Do you have a wideband yet? Whats your AFR when you see that much timing?
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Old 07-26-2014, 12:24 PM   #16
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Re: 5.3l 4l60e issues NEED HELP!

well I've been playing with OLSD so currently my AFR is like 16.5 at cruise, low load and the total advance is around 40*. yes it is jumpy. the truck computer uses a bunch of different factors to create a "final spark" number if you will.

At the time I first noticed that the timing would go way out to 45* at highway cruise I was basically stock, closed loop with MAF. maybe a few basic VE edits (in addition to new injectors) to get my LTFTs in line.
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Old 07-26-2014, 12:36 PM   #17
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Re: 5.3l 4l60e issues NEED HELP!

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Ok, we gotta take a step back here. We are no longer dealing with 1 small problem, but instead a handful of stuff stacked up. Your problems are confusing each other, we gotta try to eliminate one to see if the others change.

I still haven't seen you try a new maf yet, its plug-n-play, in 5 minutes you can put one in and see how much changes. We can't keep putting ideas out if you don't go through the process w/ us.

The timing thing is scaring me, so please put as little mileage on as you can. 45 degrees + is enough to pop your motor VERY quickly. If you see that kinda timing, your risking massive detonation. LS motors, especially truck motors, NEVER want more than MAYBE 32* (this is pertaining to basic swaps, but even specialty stuff doesn't want that much timing). That much timing WILL cause misfire and knock, and that is probably why the trans is shuffling and ignoring lockup. The p0116 is coolant temp, which means either a problem with the temp circuit, or overheating.

There may be a much greater problem in either the tune or the harness, but there is too much going on to pinpoint it. Get a new MAF to test that so we can rule it out. Can your scanner read misfire and knock counts? if so, tell me what it logs.

Who did the tune for this again?
Alright, new MAF it is. I'll also do a continuity test on all my lead wires to make sure I don't have a break in any of them. I'll post my results.
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Old 07-26-2014, 12:56 PM   #18
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Re: 5.3l 4l60e issues NEED HELP!

My reader does not read misfires. I had PCM reflashed at PSI. Since I had it reflashed, all these problems have occurred. Now, even my tach only reads half of the rpms.
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Old 07-26-2014, 02:09 PM   #19
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Re: 5.3l 4l60e issues NEED HELP!

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My reader does not read misfires. I had PCM reflashed at PSI. Since I had it reflashed, all these problems have occurred. Now, even my tach only reads half of the rpms.
Try grounding the ECM case to the body temporarily and see if anything improves. The fact that you have a growing # of failures means you got gremlins in there somewhere.
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Old 07-26-2014, 02:14 PM   #20
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Re: 5.3l 4l60e issues NEED HELP!

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well I've been playing with OLSD so currently my AFR is like 16.5 at cruise, low load and the total advance is around 40*. yes it is jumpy. the truck computer uses a bunch of different factors to create a "final spark" number if you will.

At the time I first noticed that the timing would go way out to 45* at highway cruise I was basically stock, closed loop with MAF. maybe a few basic VE edits (in addition to new injectors) to get my LTFTs in line.
Yes, but they can all be manipulated. If your getting timing that you didn't add yourself (or whoever tuned it), you can take a look and see WHY. 16.5 is very lean at cruise, I barely go that lean on decel.

Under the condition you mentioned, you want to be a hair fat, as that particular range is prone to knock. 40* is still a large amount of timing IMO, spark tables shouldn't show much over 32.

What injector are you running? Did you rely just on VE, or was PE used also?
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Old 07-30-2014, 03:03 AM   #21
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Re: 5.3l 4l60e issues NEED HELP!

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Yes, but they can all be manipulated. If your getting timing that you didn't add yourself (or whoever tuned it), you can take a look and see WHY. 16.5 is very lean at cruise, I barely go that lean on decel.

Under the condition you mentioned, you want to be a hair fat, as that particular range is prone to knock. 40* is still a large amount of timing IMO, spark tables shouldn't show much over 32.

What injector are you running? Did you rely just on VE, or was PE used also?
Okay, finally I got the MAF sensor installed. It took me awhile since I ordered the MAF that had lifetime warranty, rather than one year. Just a few dollars more. Anyhow, after installing the MAF, the truck idles much better. After a few drive cycles, at idle, LTFT% is around 7% to 10%. At cruise, it varies between 16% to 21%. So far, no p0171, P0174 codes. It will read 25% while accelerating. I am not sure if that is normal.

What I do notice is that bank 1 reads higher LTFT% by 3% compared to bank 2. Bank 1 is where I hear it missing through the exhaust at rpms higher that 1500. That is when it shuffles between 1500 to 1700. I did check the ignition timing, at cruise speed and it does read 32 to 34 degrees, unless I drop it to 3rd gear, then ignition timing rises to 40 to 45 degrees.

I am using stock injectors that came with the engine. When I had the PCM reflashed, I just gave them the engines information, transmission information, rear end ratios, and tire size. Nothing more. Everything on the engine is stock. I do have a transmission question, but I'll take your advise and tackle one issue at a time.
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Old 02-09-2015, 01:49 AM   #22
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Re: 5.3l 4l60e issues NEED HELP!

So got a chance to play around with this continued issue. Ltft still at 25% at part throttle, 10 to 18 at idle. I get p0171 and p0174 codes. Replaced intake manifold gasket as well. Replaced fuel pump and fuel filter. What I did noticed is that when I plug the pcv the ltft drops to 0% during iddle and isolates from 0-10% during part throttle. The original pcv is the one that has a small hole on the pcv. I installed the one with the check valve to see if it made a difference and it worked the same as the original one. What could cause that vacuum leak through the pcv? I replaced the grommet as well, but to no avail. Any suggestions?
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