PCMforLess - my experience - long write up

[Guenther]

First off let me say that PCMforLess has fantastic customer service and Kelly answered questions for me via e-mail several times while they were shut down between Christmas and New Years. I also called in and talked to Marshall a couple times after they were back open and he was pleasant and helpful as well. They received my PCM and sent it back out on the same day so you can't ask for faster service than that. 7 days with shipping including New Years day to send off and receive back.

All of my maintenance has been done recently since I bought the truck 3 months ago (100,000 miles) and it is running in tip top shape. Here is the list of maintenance that I have done since purchasing:

seafoamed engine
ran Techron cleaner through 2 tanks of gas
cleaned throttle body after seafoamed engine
changed plugs using AC Delco
changed CPAS
replaced both front and rear O2 sensors after seafoaming engine
changed oil to synthetic
changed fuel filter
changed front and rear differential fluids
changed transfer case fluid
changed transmission fluid
changed brake fluid
changed power steering fluid
changed air filter
thermostat was changed 10,000 miles ago and shows straight up 210*

Since the tune of my PCM I have found that I am more sluggish from a stand still. I tested the 1/4 time using my Torque program and it is actually a 1/2 second slower than stock. It is a stock truck and my PCMforLess programing choices were #1 shift firmness, no towing (Kelly walked me through that in several e-mails), no speed limiter and tuner's choice on everything else. I tow a couple snowmobiles a few times a winter but that's all so I had several questions for Kelly in regards to torque management. She again was very helpful with this and said I didn't need towing which leaves in 20% torque management.

I have noticed an increase in power beginning at about 3500rpms (great for passing) but being more sluggish off the line really negates that in my eyes as a benefit. However, it's not going to be used for a drag truck so the 1/4 mile time is not the end of the world. The shifts seem to be a little firmer and I'm glad I did not choose #2 firmness since the #1 jumps into gear fast enough and you can definitely feel the difference from stock.

My goal in getting the tune was to increase fuel economy when my foot wasn't hard on the pedal. I've read lots of posts where people say they have noticed huge improvements in power but I haven't experienced that yet (off the line anyway) in the 400 miles of driving I've done so far since the tune. I can't speak on fuel economy difference yet but I'm hoping it will be better than stock. I e-mailed Kelly about my concerns the day after I install about the power and she was quick to respond saying I should give it some time or I could send my PCM back and they would refund the shipping back to me if they found something was wrong with the tune. I don't want to have the vehicle down for another week and end up paying for shipping once again if they say everything is set the way it should be. She also said that some people notice things more than others, which I agree with because I'm a little OCD when it comes to noticing changes in my vehicles. If it skips a beat, you can bet I notice it.

One thing I didn't have to do when installing my PCM is the security reset and I have read many others have had to do this with their tune. The truck is different than stock in some ways, but I guess I was just expecting it to be livelier from a stand still rather than more sluggish. If it was more powerful from the line I think I would be happy. If I end up getting better gas mileage I will be satisfied regardless of low end. If I don't get better mileage, I will feel like I have wasted my money. Just my honest review for those who are thinking of getting a tune. Others rave about it so maybe I'm just unlucky in that I lost low end power.

 

[havie22]

IM SORRY TO HEAR THAT! I HAD MINES TUNED AND WHEN I DID I WENT WITH LEVEL #3SHIFTS AND REMOVED THE SPEED LIMITER AND THE REV LIMITER AS WELL AND ITS BEEN WONDERFULL TO ME! THE TORQUE ITS ALL TRU THE POWER BAND AND THE SHIFTS ARE NOT AS BAD AS PEOPLE HAD STATED, THEY ARE PERFECT AND THE TRUCK RESPONDS A 100 TIMES BETTER AT LOW SPEED AND ON WOT!I CAN TAKE OFF THE LINE AND IT WILL LET LOOSE ALL THE POWER WITHOUT HESITATION,AND THE MPGS GOT BETTER, I HAD TO DRIVE MINES FOR A WHILE UNTIL IT RELEARNED MY DRIVING AGAIN BUT SO FAR I HAVE NO PROBLEMS,TALK TO KELLY AGAIN AND GIVE IT A LITTLE MORE DRIVING TIME!ON MINES I CAN FEEL THE TORQUE RIGHT AFTER 2500 RPMS AND IF I OPEN IT ALL THE WAY I DONT HAVE A ROAD BIG ENOUGH FOR IT HERE IN NY,BUT IM VERY HAPPY WITH MINES.ON WET WEATHER I HAVE TO USE MY 4WD MODE BECAUSE IT WILL SPIN LIKE CRAZY,AND ON DRY PAVEMENT I CAN MAKE IT SPIN NO PROBLEM,SOMETHING ITS MISSING ON YOUR TUNE I GUESS!

 

[Fire06]

post on the fuel economy when you are in the know..

 

[havie22]

OH! DO A EXHAUST COMPRESSION TEST TO MAKE SURE NOTHING IS CLOGGED UP FOR INSTANCE THE CAT!

 

[Guenther]

IM SORRY TO HEAR THAT! I HAD MINES TUNED AND WHEN I DID I WENT WITH LEVEL #3SHIFTS AND REMOVED THE SPEED LIMITER AND THE REV LIMITER AS WELL AND ITS BEEN WONDERFULL TO ME! THE TORQUE ITS ALL TRU THE POWER BAND AND THE SHIFTS ARE NOT AS BAD AS PEOPLE HAD STATED, THEY ARE PERFECT AND THE TRUCK RESPONDS A 100 TIMES BETTER AT LOW SPEED AND ON WOT!I CAN TAKE OFF THE LINE AND IT WILL LET LOOSE ALL THE POWER WITHOUT HESITATION,AND THE MPGS GOT BETTER, I HAD TO DRIVE MINES FOR A WHILE UNTIL IT RELEARNED MY DRIVING AGAIN BUT SO FAR I HAVE NO PROBLEMS,TALK TO KELLY AGAIN AND GIVE IT A LITTLE MORE DRIVING TIME!ON MINES I CAN FEEL THE TORQUE RIGHT AFTER 2500 RPMS AND IF I OPEN IT ALL THE WAY I DONT HAVE A ROAD BIG ENOUGH FOR IT HERE IN NY,BUT IM VERY HAPPY WITH MINES.ON WET WEATHER I HAVE TO USE MY 4WD MODE BECAUSE IT WILL SPIN LIKE CRAZY,AND ON DRY PAVEMENT I CAN MAKE IT SPIN NO PROBLEM,SOMETHING ITS MISSING ON YOUR TUNE I GUESS!

havie22, you are another person who has said they have great power on the low end and I just don't have it. I've got plenty of power 1/3 of the way to the top it's just more sluggish from the start like the throttle body isn't opening up fast enough (my guess of course after seeing the video on how the throttle body works with the tune). My throttle body is clean as a whistle, truck idles so smooth I don't even know it's on sometimes and transmission is not slipping at all. My only disappointment is the sluggishness off the line but hopefully it will improve or an increase in fuel economy will squash my concern.

OH! DO A EXHAUST COMPRESSION TEST TO MAKE SURE NOTHING IS CLOGGED UP FOR INSTANCE THE CAT!

I don't think it's clogged because it would have shown signs before the tune. As I was doing the seafoam treatment it threw a code that the rear O2 sensor was slow. I cleared it and it never came back but later replaced both O2 sensors because they had 100,000 miles on them and a little preventive maintenance never hurts. I have no codes and the thing runs like a raped ape, just not on the low end from a start.

post on the fuel economy when you are in the know..

Before the tune I was getting about 14 city and 17-18 highway with the winter fuel here in Iowa. Once I drive it some more and get some figures I'll post them up.

 

[havie22]

I see! It most be something wrong with the tune then!on mines with 1/4 throttle it will go like bat out of hell!i will send it back and have them fix the problem!i have the same truck!

Also on mines right after the tune i had to replace the cat because it got clogged!i mean that may not be the issue for yours but thats why i asked about the exhaust!

 

[fadyasha]

I guess it differs from one to another depending on the different tunes u got. For me one of the biggest improvements were off the start line! Smaller cars with 2.4 - 2.8 engines would be neck to neck when taking off but just today on my way home i was the first to take off and a Camry with a 2.4 engine couldn't keep up. A few days earlier with the new Kia optima. When u compare the weight and the age Difference between cars I find it Impressive. Shifting is a plus went with level 2.

You may wanna check ur exhaust system like havie22 mentioned and also make sure your barrels r in good shape. If theyre clogged up your start will be sluggish, throttle body as well, air filter too. Battery connections r good and not rusted, a whole bunch of possibilities.

This is based on my experience and may be wrong

 

[Guenther]

I guess it differs from one to another depending on the different tunes u got. For me one of the biggest improvements were off the start line! Smaller cars with 2.4 - 2.8 engines would be neck to neck when taking off but just today on my way home i was the first to take off and a Camry with a 2.4 engine couldn't keep up. A few days earlier with the new Kia optima. When u compare the weight and the age Difference between cars I find it Impressive. Shifting is a plus went with level 2.

You may wanna check ur exhaust system like havie22 mentioned and also make sure your barrels r in good shape. If theyre clogged up your start will be sluggish, throttle body as well, air filter too. Battery connections r good and not rusted, a whole bunch of possibilities.

This is based on my experience and may be wrong

As stated above all maintenance has been performed already. I have no issues other than it isn't a peppy off the line as it was before the tune. If anything was clogged I would imagine I would have issue other than it being a little slower than stock off the line. It doesn't pull hard until around 3500rpms but it never chugs, bogs, misses or skips at all.

 

[khill]

Gotta say, I'm another who noticed the increased low end. Led me to spinning my tires on a few takeoffs that I wasn't expecting. Took some getting used to.

Something about your maintenance: Did you unhook the battery or pull the PCM fuses while doing all the tasks you listed? You said you did all that since purchased, so you've been altering your performance tables with all of the maintenance you've been doing on your truck. Just for the heck of it, try disconnecting the PCM overnight and see what happens, it's always a good idea to do after doing maintenance on your truck, lets the PCM relearn how to drive with changed parameters.

 

[Guenther]

Gotta say, I'm another who noticed the increased low end. Led me to spinning my tires on a few takeoffs that I wasn't expecting. Took some getting used to.

Something about your maintenance: Did you unhook the battery or pull the PCM fuses while doing all the tasks you listed? You said you did all that since purchased, so you've been altering your performance tables with all of the maintenance you've been doing on your truck. Just for the heck of it, try disconnecting the PCM overnight and see what happens, it's always a good idea to do after doing maintenance on your truck, lets the PCM relearn how to drive with changed parameters.

All maintenance was done before the tune and battery was unhooked during maintenance for extended lengths of time when necessary. The truck obviously had the battery unhooked for a week until I reinstalled the PCM after getting it back. It was also unhooked a few days after the PCM install for a couple hours when I installed a small powered subwoofer. I'll give it another shot unhooking the battery though. There is no way mine would spin the tires unless it was a little wet out.

 

[khill]

Could it be the pedal sensor? Whatever the error is it is reducing the amount of power you get on low end. I found it very easy to break my nice expensive road tires loose on bone dry pavement, so I'm guessing something is wrong. If you have a live scan tool you can also check TPS values...

Again, this is all supposition. Checking the car for issues while hoping the PCM is flashed right is like taking a hypochondriac to a doctor. You don't know whether the problem is in the body or the brain.

Depending on how much budget shipping is, I would just ship it back to PCM4L and have them make sure it is not their fault. USPS has those nice "If it fits it ships for a low flat fee" boxes... Yeah the delay sucks, but I would do it just to know whether or not something is wrong with my TB. Then again, I don't need my TB on a day to day basis.

 

[khill]

also, just for the heck of it, this is straight out of the service manual, engine troubleshooting:

Problem
-Possible Cause :: Next Step

Poor Acceleration:
-Incorrect Ignition Timing :: Reset Timing
-Leaky Valves :: Check Compression
-Weak Fuel Pump :: Replace Pump
-Dirty Fuel Injectors :: Clean/Replace Injectors
-Excessive Intake Valve Deposits :: Clean Intake System

 

[Guenther]

Could it be the pedal sensor? Whatever the error is it is reducing the amount of power you get on low end. I found it very easy to break my nice expensive road tires loose on bone dry pavement, so I'm guessing something is wrong. If you have a live scan tool you can also check TPS values...

Just got done working out so I drove the Envoy and at idle the TPS read 14.1 (29.0 when the truck is off). When I hit the go fast pedal it instantly jumps and seems consistent with where I believe my foot is in the travel of the pedal. Excellent thought though.

 

[Guenther]

Thanks for the ideas. The responses are as follows:

also, just for the heck of it, this is straight out of the service manual, engine troubleshooting:

Problem
-Possible Cause :: Next Step

Poor Acceleration:
-Incorrect Ignition Timing :: Reset Timing - don't know how to do that one

-Leaky Valves :: Check Compression - I can do that if needed however it's running like a champ in every other way so I don't think there's a problem

-Weak Fuel Pump :: Replace Pump - Don't have a way to test if but I would think if it was bad I'd have an issue every time I put my foot in it at any rpm and it's only just at the low end.

-Dirty Fuel Injectors :: Clean/Replace Injectors - I've ran 2 big bottles of Techron through it at concentrated rate. It wasn't doing anything wrong I just thought I should probably do it as long as I was doing everything else. Not a hiccup, blip, jump, miss, stall, ect.

-Excessive Intake Valve Deposits :: Clean Intake System - Ran a bottle of seafoam through the brake booster to clean intake as well as cleaning the throttle body

 

[khill]

Ign timing would be via a PCM flash. Comp test and injectors don't seem necessary for your situation. That's just all the service manual says.

Then again sometimes it really is an oddball solution that fixes things.

 

[Guenther]

Ign timing would be via a PCM flash. Comp test and injectors don't seem necessary for your situation. That's just all the service manual says.

Then again sometimes it really is an oddball solution that fixes things.

I'm with ya brother. Maybe I just need to keep my sunglasses in the middle compartment instead of the sunglasses holder. Or leave a DVD playing all the time on the entertainment center. Gone in 60 Seconds might give me about 50hp

 

[khill]

You could always try a half dozen cans of seafoam, that appears to be fixing my random misfiring

 

[jimmyjam]

i'm not sure what you are using for data acquisition, if you can see knock count or knock retard. i'd check to see if at take off it is seeing knock and pulling timing. could be that the timing is more aggressive than stock, you are getting knock under load at low rpm and it is pulling timing to compensate, and the end result being less timing advance than stock

just a guess

 

[Guenther]

i'm not sure what you are using for data acquisition, if you can see knock count or knock retard. i'd check to see if at take off it is seeing knock and pulling timing. could be that the timing is more aggressive than stock, you are getting knock under load at low rpm and it is pulling timing to compensate, and the end result being less timing advance than stock

just a guess

Thanks jimmyjam. I have no knocks that I can hear or feel. The truck is quiet and smoooooth. I've got the Torque program using the ELM327 bluetooth but don't know what to use to find a knock count or knock retard. I drove it this morning after disconnecting the battery last night once again and I might have seen an improvement but we finally got some snow and ice here in Iowa last night so it's hard to tell.

 

[jimmyjam]

i think at the very least torque should show timing advance but you won't really know what you are comparing it to unless someone else with torque and a tune gets you some comparative data.

or find someone with hpt or efilive and do some logging, you'll know if there is an issue immediatly. otherwise you are just guessing. what you can "hear or feel" is irrelevant, you need to know what the computer thinks it is feeling and hearing

 

[Guenther]

Makes sense.

 

[Fire06]

This is sounding like a pain in the ass problem and I really hate those kind

 

[Guenther]

m

This is sounding like a pain in the ass problem and I really hate those kind

Me too. I let it set again unhook over night last night and today it seems to be better. Not tire burning power but it's not real sluggish anymore. Maybe 4th time was the charm.

 

[Fire06]

Remember the power of positive thinking