Secondary Air Injection Pump Failure on V8's! Important!

[Silver_midlife_t4r]

I just installed the AIP bypass from [MENTION=8828]slyfox75[/MENTION] . Easy to do, but I really took my time to get it right. I disconnected my battery while doing this just to make sure I didn't screw anything up. After the installation, the first time I started it, it cranked a few times (sounded normal), but didn't start. Second time started without issue. I tried to recreate the 'no start' issue by starting and stopping leaving it off for about 30 seconds at a time, and it started consistently on the first try. I waited about half an hour, and tried again. And again it didn't start on the first try. Did I do something wrong? Or is it related to the battery disconnect? Any thoughts?
Thanks

 

[slyfox75]

Others can chime in......but the battery disconnect is your culprit. The ECU is trying to figure out all your "stuff".....coil info.....spark plug gap(resistance)...blah blah......Blackworks can chime in but I think its pretty normal(mine rarely starts on first attempt after battery)......what's not normal is starting, stopping, starting, stopping.....Keep doing that and you'll need a new starter......and guess where its located

HAVE FAITH BROTHER! The bypass is bulletproof. Proven time and time again(as long as ya'll install them correctly

Your good, sleep tight tonight. Real test will be in the morning.

Still sell'um.(I get a lot of emails just asking) email [email protected] w questions $45 shipped......$50 if you want one autographed.....ok the wine is talking now I'll be in Gulf Shores,AL this week.....so none are shipping, but will be back Friday(7/22) and have some ready to ship if needed.

 

[Silver_midlife_t4r]

[MENTION=8828]slyfox75[/MENTION] Thank you so much! That's what I was hoping was the issue. I left it alone since just before my last post, and then headed out for dinner and no trouble at all. I didn't think it was the bypass. It was super easy, and your directions were great! Thanks again.

 

[mpyle]

Mine never starts on the first try after I have disconnected the battery. But it does Start immediately and consistently after the first crank.

Sent from my SAMSUNG-SM-N910A using Tapatalk

 

[07V8]

I just installed the AIP bypass from [MENTION=8828]slyfox75[/MENTION] . Easy to do, but I really took my time to get it right. I disconnected my battery while doing this just to make sure I didn't screw anything up. After the installation, the first time I started it, it cranked a few times (sounded normal), but didn't start. Second time started without issue. I tried to recreate the 'no start' issue by starting and stopping leaving it off for about 30 seconds at a time, and it started consistently on the first try. I waited about half an hour, and tried again. And again it didn't start on the first try. Did I do something wrong? Or is it related to the battery disconnect? Any thoughts?
Thanks

Mine has done this EVERY single time I disconnect the battery. You're fine.

 

[Billynath1988]

its the crank position sensor relearning process.. its fine

 

[thenuka]

Are there any members in Calgary that has the AIP bypass installed? I'd like to compare notes on the initial loud sound I get when I start on some days.

I installed the bypass but worried that it is not in properly. I did check it with a multimeter and looked ok.

Anyone in Calgary willing to meet up?


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[LordAbdullah]

04 v8

I have an 04' V8, it makes a sound awfully close to what's being described here. It lasts about 2-3 minutes, but from what I've read, it doesn't affect the older models. Any ideas as to what this may be?

 

[Billynath1988]

I have an 04' V8, it makes a sound awfully close to what's being described here. It lasts about 2-3 minutes, but from what I've read, it doesn't affect the older models. Any ideas as to what this may be?

probably this.. get the kit and be done with it

 

[07V8]

probably this.. get the kit and be done with it

Definitely not this. The system is only installed on 05 and later V8s.

 

[Billynath1988]

Definitely not this. The system is only installed on 05 and later V8s.

Is that fact? I thought tundras and sequoias from this year pre vvti had this issue too.

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[07V8]

Is that fact? I thought tundras and sequoias from this year pre vvti had this issue too.

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That is a fact. VVT-i V8s only.

 

[LordAbdullah]

That is a fact. VVT-i V8s only.

Thanks for the advice! I guess I'll record it and put a link up, see what people suggest. Kind of glad the 04 doesn't have this issue!

 

[CXS]

I just read this thread a bit ago and since I have an '05 with 207,000 on it w/o issues so I figured I shouldn't push my luck any longer and bought [MENTION=8828]slyfox75[/MENTION]'s $45.00 kit. I'm not the best when it comes to wiring but when the instructions started with "keys on the floor" I knew I could follow his directions. Very easy, maybe 10 minutes to install, the biggest problem I had was getting the Velcro adhesive protection off.

If you're hesitant to do this based on your skill level, go or it. My experience proves that even a wiring idiot can install it easily!

:reddance:

 

[CXS]

Following up on my own post. I'm not about to read through this thread to find where someone asked about emissions testing compatibility but someone in Denver asked IIRC.

The answer is 'yes' I went through a week or so ago, the popped the hood, looked around for a bit then tested. Even at 207,000 miles my truck passed with flying colors. So if you're in an emissions area I think it's safe for anyone to use this bypass.

 

[ben550]

Just got code 2445 (4.7 v8) and I'm in limp mode. Unfortunately I'm 200 miles away from home (I live in the Bay Area but am in Lake Tahoe).

I'd like to do the bypass fix but I have no tools so I'd like to get out of limp and at least get home where I have my tools.

Here's what I'm thinking:

1) Tomorrow morning, warm up the car while it is still in limp mode
2) Pull it in the garage and reset the ECU by disconnecting the battery
3) Start the car and drive home

Correct me if I'm wrong. But as long as I start the vehicle while it's still warm (after the battery reset), it shouldn't kick off the AIP system right?

I'm hoping this will be enough to get me home and I don't want to get stuck in limp mode in the mountains driving back.

You should be ok if the doors are stuck closed. If they are stuck open I think you'll still be out of luck.

 

[NeutronJon]

Secondary Air System Overview

I stumbled across this thread and wanted to do a bit of research on how the secondary air system works so that I could better understand the bypass. I found this page of the FSM describes the system, and helps understand why bypassing the temperature sensor on startup is the best solution.

If you look at the diagram on the bottom half of the page, you see that the flow path is from the air intake, through the pump, through two sets of valves, and out through the exhaust just after the cylinder exhaust valves.

The ECM appears to have 4 functions that check system health (based on the diagram, and what codes people have posted). The first checks the health of the air pump motor, likely by taking a resistance reading. The FSM states that this resistance should be 33-39 ohms at 20 C (68 F) if you check it manually. So, if your pump is failed, I suspect that adding a 36 ohm resistor (36 Ohm 1W Flameproof Resistor 10 Pcs.) should fool the ECU into believing that the motor is not open or shorted. The second diagnostic is verifying that the pump produces the required air pressure, and it may check that it shut off after startup. This is done by the pressure sensor between the pump and the first air switching valve. By installing the temperature bypass kits, the pump is never demanded to come on so we don't need to fool the pressure sensor.

Since measuring valve position is more difficult and more likely to fail (combined with the fact that there are no feedback arrows coming from the valves to the ECM) I suspect that the valve failure codes are driven by improper pressure signals from the pressure sensor. A failed open valve would be determined by pressure being present after startup (and overcome by installing the plates between the switching valves and the exhaust) and a failed closed valve would be sensed by too high of a discharge pressure when the air pump is expected to be running. Again, this is fixed by never requiring the pumps to run.

Overall, great job to the designers of the kit. I have an 05 V8 that just crossed 164k miles. I can say that I'm lucky since my truck has lived in new england and the mid atlantic region for its entire life, so I'm sure that my system has seen a fair amount of use.

NOTE: The resistor I proposed would need to be used in conjunction with the bypass kit from slyfox or hewitt. The resistor is only to fool the ECU into believing the fan motor is not open or shorted and should not be needed unless you are installing the kit after the fan motor has failed.

 

[07V8]

I stumbled across this thread and wanted to do a bit of research on how the secondary air system works so that I could better understand the bypass. I found this page of the FSM describes the system, and helps understand why bypassing the temperature sensor on startup is the best solution.

If you look at the diagram on the bottom half of the page, you see that the flow path is from the air intake, through the pump, through two sets of valves, and out through the exhaust just after the cylinder exhaust valves.

The ECM appears to have 4 functions that check system health (based on the diagram, and what codes people have posted). The first checks the health of the air pump motor, likely by taking a resistance reading. The FSM states that this resistance should be 33-39 ohms at 20 C (68 F) if you check it manually. So, if your pump is failed, I suspect that adding a 36 ohm resistor (36 Ohm 1W Flameproof Resistor 10 Pcs.) should fool the ECU into believing that the motor is not open or shorted. The second diagnostic is verifying that the pump produces the required air pressure, and it may check that it shut off after startup. This is done by the pressure sensor between the pump and the first air switching valve. By installing the temperature bypass kits, the pump is never demanded to come on so we don't need to fool the pressure sensor.

Since measuring valve position is more difficult and more likely to fail (combined with the fact that there are no feedback arrows coming from the valves to the ECM) I suspect that the valve failure codes are driven by improper pressure signals from the pressure sensor. A failed open valve would be determined by pressure being present after startup (and overcome by installing the plates between the switching valves and the exhaust) and a failed closed valve would be sensed by too high of a discharge pressure when the air pump is expected to be running. Again, this is fixed by never requiring the pumps to run.

Overall, great job to the designers of the kit. I have an 05 V8 that just crossed 164k miles. I can say that I'm lucky since my truck has lived in new england and the mid atlantic region for its entire life, so I'm sure that my system has seen a fair amount of use.

NOTE: The resistor I proposed would need to be used in conjunction with the bypass kit from slyfox or hewitt. The resistor is only to fool the ECU into believing the fan motor is not open or shorted and should not be needed unless you are installing the kit after the fan motor has failed.

I'm confused what the resistor does in addition to the bypass kit? The kits already disable the system completely. If the systems never activated, why would the valve position ever change?

 

[Awz]

Alright, so this is something that I've been fighting. I originally wanted to go the "correct" way and had the parts replaced. P2440 came back, limp mode. I bought the hewitt-tech bypass. Still getting the code. Bank1 valve open. The only thing I can think is that the sensor is bad. The block off plates are in place so they can't be getting a pressure spike. This is what Hewitt suggested but I wanted to get some other opinions, or see if anyone else has encountered this. I've spent $2000 so far on this POS and am tired of clearing the code all the time. The weird thing, at least to me, is that is only comes on after several short trips. 16 degrees on the way to work and no problem. Stop at the gas station, then the store, stop to get something to eat, I need to clear it a couple of times. (I have a basic scanner, no battery disconnect). Any other ideas? Are the sensors part of the valve assembly?

Thanks

 

[NeutronJon]

I'm confused what the resistor does in addition to the bypass kit? The kits already disable the system completely. If the systems never activated, why would the valve position ever change?

The resistor has nothing to do with the valves. This is if you get a code for a bad air pump with the bypass kit installed. I'm not sure that the ECM checks the resistance of the motor before attempting to use it, but if so, I think this would work.

This is a theoretical solution for people who are not as good with print reading, are still getting pump codes with the bypass, and really don't have anything else to lose before shelling out the money on a new pump.