fuel service

[elwesso]

I have heard that a rail flush is something that should be done, and that it is probably better to do it before you replace the plugs, as not to gum up the new plugs with all the gunk. Do most independant shops have the capability to do this, or am I going to have to go somewhere special?

[Q45tech]

The high pressure spray cleaning of the plenum and runners tends to dislodge more EGR/dirt than a rail flush since the fuel filter does a pretty good job. The plenum/ runners probably have a 1000 times more crud by weight than the rails/injectors. Plus the 4" passed the injectors is kept reasonably clean by the gasoline washing action......Build up on the intake valve top and stem is usually minor if the fuels additive package has enough detergents {?}.

The 94 and later use a different injector which seems more tolerant to build up...........not to say it wouldn't/couldn't be helped by 60k or 100k cleanings.

If the power balance test is within 12 rpms [1% variance at 1200 rpm] injector things are clean.........25-37 drop seems to be noticeable and more is a definite sign of work being required.

[bgilly]

Q45tech: In your experience, has the spray cleaning method ended up fouling the plugs from all the extra carbon/gunk being released in to the combustion chambers? I am thinking of doing this cleaning soon, but since my plugs are fairly new, I'd rather not have to change them.

[Q45tech]

When ever we do a plenum / TB cleaning we always excercise the engine in the short after service test drive. Floor it and run it to redline in 1st gear a few times to heat the crud up and blow it out the exhaust.

Only see fouling from drivers not reving the engine up enough in day to day driving.

[airman]

Should I do manual plenum/TB cleaning before getting 3-stage BG injection service at the dealer? Or this BG service fullfills that?

[bgilly]

When ever we do a plenum / TB cleaning we always excercise the engine in the short after service test drive. Floor it and run it to redline in 1st gear a few times to heat the crud up and blow it out the exhaust.

Only see fouling from drivers not reving the engine up enough in day to day driving.

I think I can handle that. :icesangel

[elwesso]

So you actually spray stuff right in to the TB?? Sounds like something that can be done at home. Should I get some regular TB cleaner (like NAPA brand) or get something special?

While im at it, how effectively can the plenum be cleaned on the car, with the TB off?

[Q45tech]

The BG high pressure [special system] sprays solvent into the air passage in front of TB while the engine is running for 15-20 minutes vs the manual clean with a spray can and tooth brush and lots of rags.

[bgilly]

I've used MCCC (Mopar Combustion Chamber Cleaner) on other cars, and it works very well. It's in an aerosol can.

[elwesso]

So for what its worth, is it almost more effective to take off the TB and clean it and reach inside the plenum? Or do the aerosol type things you spray in the TB work fine?

[bgilly]

Well, they kinda do 2 different things. The spray method cleans the valves too, along with parts of the intake runners that you can't reach. But as far as a thorough cleaning, doing it by hand is better, for the parts you can reach anyways.

[elwesso]

MKAY!!

So i guess ill take off the TB and clean it and reach inside the plenum, and then put it all back together and spray in the stuff after!

Sound like a plan?

[bgilly]

sounds great to me!

[Q45tech]

You have to understand that the BG induction system sprays 12 ounces in a very fine mist at 50 psi thru a special fogger s shaped attachment that slips between the TB and the induction hose while the engine is running vs spraying a stream from some can or sucking some liquid thru a vacuum hose.

Big drops will condense [and settle in the bottom of plenum] long before they get down the runners in conventional methods.

[elwesso]

Obviously the BG thing is going to be more effective, but for my benefits and purposes, will it work good enough, or should I pay the money to have the BG done.

Could you make some sort of apparatus to go all the way to the flapper thing inside the TB, so the spray wouldnt get into the vacuum lines?

[bgilly]

The MCCC has fine enough of a spray so that I've never had a problem with it condensing in the intake. Plus you have to have a friend rev the motor for you while you do it to keep the motor alive (since you have to spray it in to an open vacuum line, therefore creating a large vacuum leak), so that will cause enough suction to keep it out of any nearby vacuum lines and give the motor a good cleaning. In other words, don't worry about how close you are to the throttle plate, just spray it in anywhere after the MAS and you'll be fine. Have your friend hold the RPMs at about 3000-4000 while you spray it in, because every time you spray it the motor will drop rpms real quick.

[elwesso]

I assume it is OK to take off the intake hose and spray it right into the TB?

[DAEDALUS]

I dont' think it would have any more or less of a long-term impact on the car, but I wonder how the car would run without the MAF being in the airflow.

[bgilly]

elwesso: if the motor will run like that, then yes, its OK. Just spray in short bursts so you don't hydrolock the motor. I'd imagine you'll have a heck of a time keeping it running, but most cars will run without the MAF. Just not very well.

[elwesso]

Ok, if it wont run (or run good) without the MAF, what would be the alternative?

[DAEDALUS]

You can remove top of the airbox and spray the cleaner past the MAF sensor using the straw. Just be careful that 1) You don't damage the MAF, and 2) that the straw doesn't come off and get sucked into the intake. Alternatively, you can remove one of the small vacuum lines attached to the intake and spray the cleaner through the small opening.

[AZhitman]

Alternatively, you can remove one of the small vacuum lines attached to the intake and spray the cleaner through the small opening.

Better idea.

Third, you can drill a tiny hole in the plastic intake hose near TB, insert straw, and work the throttle yourself while introducing the cleaner. When done, patch hole w/silicone.

[elwesso]

I like that idea best. Best yet, no taking apart anything!

So how much should I induce? Less than or more than 1 can?

[bgilly]

At least one can.