X66P Upper Engine & F.I. Cleaner (88861803)

[rizzo20]

https://www.amazon.com/gp/product/B00BK7LR36/?tag=gmtnation-20

Anyone use this stuff? It can't be dumped into the fuel tank and has to be fed through a fuel injector cleaning device. I wonder if it could be introduced to the engine through the brake booster like Seafoam?

I have a P1174 code on my 4.2 that will not go away. Here's what I've done: replaced both Oxygen sensors, replaced all plugs, cleaned throttle body, ran several different brands of F.I. cleaner through gas tank, use 89 Octane, replaced thermostat (yellow sludge moisture was forming in intake resonator before this due to low temps) . I might try Seafoaming but this stuff looks like it is directly designed for my issue. Any thoughts?

 

[mrrsm]

You don't mention having replaced the Fuel Filter yet... but it might help doing that before trying any "Through the Tank" & "On the Vehicle" BG-44 Fuel System Cleaner and use the BIG Bottle of Chevron Techron EFI Cleaner as it is probably as the strongest of the lot. You've probably already tried most of these... but for the sake of your Readers who might want to know more about what is being suggested as good, this article provides a good background:

http://www.hcdmag.com/best-fuel-injector-cleaner/

Alternatively, after you change the Fuel Filter and before you decide to go through the complicated and mostly ineffective GM Top Engine "On The Vehicle" EFI Cleaning Procedures, consider filling the tank to the brim with Chevron High Octane Gasoline (also with Techron) at the very same time you dump in the Chevron Techron Additive and see if things improve. By the way... You should avoid using the GM TEC Additive through the Fuel Tank because in concentration settling to the bottom of the tank... it can dissolve the seals inside of the Fuel Pump :

GMT Nation's ever redoubtable and famous @MAY03LT has this excellent Youtube video on “How to Change the Fuel Filter on the Trailblazer, Envoy...”:

 

[gmcman]

First of all, If your PCM is stock, then I would stop using the 89 octane for now and try some 87

Reason is, to get 89, some pumps have to mix the 93 with the 87 and because of the prices, 93 very likely sits in the tank for awhile. Some stations have a tank for 89, some do not.

I have a bottle of what you have linked, and yes, it's not something you pour into your tank.

Let me verify the ratio but I'm pretty sure it needs to be mixed with 7 parts gasoline to one part cleaner. I use a spray bottle and spray into the throttle body while it's running around 1500-2000 RPM. Take a piece of 2x4 or similar and use the power seat to press against the gas pedal to hold the rpm.

Sounds like you may have an injector issue, but first thing I would do is verify ALL the intake manifold bolts are tight, even the one hidden under the molded vacuum hose between cyl 3 & 4. The bolts get loose quite often after the intake seal becomes flattened out.....be careful, only 89 INCH POUNDS of torque on the bolts... 1/4" drive, 10MM socket.

If that checks out, then I would get some of this and run it through your tank.


After that, follow up with some 44K.



Believe me that loose intake manifold bolts will cause a myriad of fuel issues.

Another option is a faulty fuel pressure regulator. Unfortunately it's one of those things that you cannot easily test or even test at all, sometimes it's just good to blindly change unknowing of it's condition but the end result is knowing it's good.

I changed mine awhile back chasing some lost MPG's and it did seem to smooth the acceleration out a little, after about 12 years I figured why not.

Aside from that, you may very well need to remove your injectors and have then professionally cleaned. Try the other options first.

 

[rizzo20]

You don't mention having replaced the Fuel Filter yet... but it might help doing that before trying any "Through the Tank" & "On the Vehicle" BG-44 Fuel System Cleaner and use the BIG Bottle of Chevron Techron EFI Cleaner as it is probably as the strongest of the lot. You've probably already tried most of these... but for the sake of your Readers who might want to know more about what is being suggested as good, this article provides a good background:

http://www.hcdmag.com/best-fuel-injector-cleaner/

Alternatively, after you change the Fuel Filter and before you decide to go through the complicated and mostly ineffective GM Top Engine "On The Vehicle" EFI Cleaning Procedures, consider filling the tank to the brim with Chevron High Octane Gasoline (also with Techron) at the very same time you dump in the Chevron Techron Additive and see if things improve. By the way... You should avoid using the GM TEC Additive through the Fuel Tank because in concentration settling to the bottom of the tank... it can dissolve the seals inside of the Fuel Pump :

GMT Nation's ever redoubtable and famous @MAY03LT has this excellent Youtube video on “How to Change the Fuel Filter on the Trailblazer, Envoy...”:

First of all, If your PCM is stock, then I would stop using the 89 octane for now and try some 87

Reason is, to get 89, some pumps have to mix the 93 with the 87 and because of the prices, 93 very likely sits in the tank for awhile. Some stations have a tank for 89, some do not.

I have a bottle of what you have linked, and yes, it's not something you pour into your tank.

Let me verify the ratio but I'm pretty sure it needs to be mixed with 7 parts gasoline to one part cleaner. I use a spray bottle and spray into the throttle body while it's running around 1500-2000 RPM. Take a piece of 2x4 or similar and use the power seat to press against the gas pedal to hold the rpm.

Sounds like you may have an injector issue, but first thing I would do is verify ALL the intake manifold bolts are tight, even the one hidden under the molded vacuum hose between cyl 3 & 4. The bolts get loose quite often after the intake seal becomes flattened out.....be careful, only 89 INCH POUNDS of torque on the bolts... 1/4" drive, 10MM socket.

If that checks out, then I would get some of this and run it through your tank.
View attachment 80475

After that, follow up with some 44K.

View attachment 80476

Believe me that loose intake manifold bolts will cause a myriad of fuel issues.

Another option is a faulty fuel pressure regulator. Unfortunately it's one of those things that you cannot easily test or even test at all, sometimes it's just good to blindly change unknowing of it's condition but the end result is knowing it's good.

I changed mine awhile back chasing some lost MPG's and it did seem to smooth the acceleration out a little, after about 12 years I figured why not.

Aside from that, you may very well need to remove your injectors and have then professionally cleaned. Try the other options first.

Thanks for the info guys! My PCM has been tuned for 89 (P1174 was coming up before PCM was tuned) I've never used any of those additives mentioned above. I've used Gumout and Berryman B-12. I have not changed the fuel filter and will do that next. I also will check those manifold bolts.

I'm selling this Envoy (Picking up another Envoy this evening) and I want this problem fixed before I sell it. I won't clear the code and pass this issue on to the next guy like what was done to me I believe. Thanks again for your input and I will report back once I've done these things.

 

[gmcman]

2008, I don't believe you have a replaceable fuel filter.

 

[TripleBuick]

I just had my GM dealer perform the fuel injection cleaning and it worked amazing. I had a P0171 code and it was a dirty injector causing it. Tried Gumout in the tank, it helped but didn't solve it. The product GM uses requires the mechanic to turn off the fuel pump, attach a cannister with the cleaner to the fuel line, pressurize it using an air compressor, then run the engine on 100% cleaner for about 10 to 15 minutes until the cleaner runs out. I paid $110 at GM. Worth every penny.

 

[Wooluf1952]

2008, I don't believe you have a replaceable fuel filter.

The only filter is the one in the tank.

 

[rizzo20]

Let me verify the ratio but I'm pretty sure it needs to be mixed with 7 parts gasoline to one part cleaner. I use a spray bottle and spray into the throttle body while it's running around 1500-2000 RPM. Take a piece of 2x4 or similar and use the power seat to press against the gas pedal to hold the rpm.

Sounds like you may have an injector issue, but first thing I would do is verify ALL the intake manifold bolts are tight, even the one hidden under the molded vacuum hose between cyl 3 & 4. The bolts get loose quite often after the intake seal becomes flattened out.....be careful, only 89 INCH POUNDS of torque on the bolts... 1/4" drive, 10MM socket.

If that checks out, then I would get some of this and run it through your tank.

@gmcman It's been awhile since I've messed with this but I tightened up the intake manifold bolts (they were somewhat loose) as suggested, reset the PCM and driven about 100 miles and the P1174 has come back. I searched everywhere I could think of for a vacuum leak with no luck.

I'd like to try those BG products but haven't been able to find them. Where have you purchased them?

 

[xavierny25]

@rizzo20 I get them through Amazon

 

[seanpooh]

Yeah, that GM stuff you do not put though the intake manifold. It is used with a pressurized tool connected directly to the fuel injector rail. I know, I work for the dealer now... :-(