Snowplow Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
748 Posts
Discussion Starter #1
I did a little work on my 97 GMC last weekend. With 135,000 miles, I thought I would give it some induction maintenance. I pulled the Mass Airflow Sensor and cleaned it with CRC MAF cleaner. Super easy job. Then I pulled the Throttle Body and cleaned it, along with the Idle Air Control. TB came off in just a few minutes. Two Torx screws for the IAC, two more for the Throttle Position Sensor. Took the TPS off so I wouldn't have to worry about damaging it with excess TB Cleaner. Sprayed some TB cleaner on the TB and used an old toothbrush and scrubbed it down. Cleaned the bore, throttle plate, and IAC port. Took a couple of passes, but it cleaned up very nicely. Gave the IAC a couple of quick squirts. Put everything back together, truck started right up. I reused the TB to intake gasket. Once she was running and warmed back up, I pulled the brake booster vacuum line. Poured a bottle of Sea Foam in very slowly (use a funnel). Had some pretty nasty crap coming out of the tailpipe. Put another can of Sea Foam in the tank. I have since run that tank down and filled back up.
There have been some very noticeable improvements since I did this. First of all, and immediately, the throttle response is much better. Truck feels much smarter off the line. The idle is smoother, the whole truck feels smoother. I didn't think it made much difference under a light load, but have noticed I have been speeding more often in places I go frequently. And yesterday I noticed the truck is holding OD longer before downshifting.

So, for an hours time and $25 bucks or so, made a great improvement in the truck.
TB Before1.jpg

TB Before2.jpg

TB After1.jpg
More results today . Put the truck to work hauling my dump trailer today filled with roofing. Truck and trailer combined at least 14K pounds, if not 15K. This thing seriously feels like a brand new truck. The mid range power is amazing. Hauling the trailer, I didn't even feel it on the flats. I was able to accelerate on hills that I could barely maintain speed on before, all in higher gears and lower RPMS. I didn't even have to go wide open on the big hill before my house. That used to be wide open, drop all the way to first, 30 mph. Was doing 45 in second with the TC locked up this time.

Six months ago I thought I would be changing motors. Ripping out the Bosch+4 late last winter and putting in the AC Delco's gapped at .040 made a big difference, the truck was at least driveable. The work last weekend really woke the truck up. Some time spent online really paid off.
 

·
Registered
Joined
·
748 Posts
Discussion Starter #2
Fuel Economy update: Went on a 180 or so mile trip today. Mix of rural roads 40-60 mph, interstate 60-75mph, and about a half hour in the city. Pulled 15MPG. That's about 7% better than my previous best, nothing to sneeze at. Could probably squeeze 16 or better on a long trip at moderate speeds.

I would recommend anyone with 50K or more on their truck to do this. Cheap, quick, and easy. Big returns.
 

·
Registered
Joined
·
17 Posts
It seem they get carbon fast when heavy on gas. How I know I clean throttle body on 89 F150 4.9L

one of my friend's Dad own 2002 Expedition 5.4L it have 280,000 miles first time he clean throttle body. Wow never see that much carbon fill in throttle body after that it run great and smooth.


you should add vacuum gauge on that. That mean you could gotten 18-20 mpg with vacuum gauge. How? they tell if you are heavy foot on gas. I gotten 14 mpg in 96 E350 15 passenger which weight 3,000 with 351W in city.
 

·
Registered
Joined
·
3,937 Posts
Ive had good luck shooting the intake full of seafoam,with the engine hot,the spray can,just hold throttle open and fill intake,let it sit at least a 1/2 hr.my 8.1 really liked it,got rid of some carbon,and did a good immitation of the Coal furnace upon start up after.
 

·
Registered
Joined
·
8,323 Posts
One thing that works as good,if not better than Seafoam,is Ford "Tune Up Cleaner".Part number is CXC-52B,and it's cheap.

It can be used for throttle body and air valve cleaning,and engine decarbonizing.Get er hot,and spray the whole can past the throttle plate while playing with the throttle enough to keep it running.As the can runs out,let it stall,then sit for 30 mins.Take er for a good drive,you will be suprised at what will come out the pipe.
 

·
Registered
Joined
·
69 Posts
Sounds like my 98 GMC needs this done.
Not a mechanic, parts changer at best. Where on the 98 would I spray?
Thanks in advance!!!
 

·
Registered
Joined
·
748 Posts
Discussion Starter #8
Sounds like my 98 GMC needs this done.
Not a mechanic, parts changer at best. Where on the 98 would I spray?
Thanks in advance!!!
To really get the TB clean, you need to pull it from the truck. There is one wingnut jig holder the air duct to the TB. And loosen the clamps on the air ducts to the filter box. You need to do this anyway to clean the MAF. After the duct is off, there is a bracket for the throttle/cc cables on the front of the TB you need to pull. 10 mm. Take that off, and remove the cables. Then three studs/bolts hold the TB down. 10 mm deep socket. Unplug your wiring, and you have it. The TPS and IAC valves are held on with Torx screws, mine were different sizes. Also pay attention to the clock position of the the TPS and IAC. You might want to scratch or draw marks to be sure. Just remember which screws held which item. All apart now, just spray with TB cleaner and a toothbrush. Really clean the IAC port too, and the IAC itself.

When I did the MAF, I pulled the four screws that sandwich the MAF between the duct adapters. Pay close attention to how everything is put together. It will only go one way, but save yourself some confusion. When you clean the MAF, use CRC MAF cleaner only. Just spray the wires, both sides. You can do each side a couple of times. Don't touch the wires with anything. No fingers, brushes, Qtips, nothing. No compressed air, and don't touch the spray tube to them. They're very delicate. Put everything together and start her up. Then you can pour the SeaFoam into the vacuum line.
 

·
Registered
Joined
·
69 Posts
Thanks. I am out of town for awhile, when I get home I''ll try it and you know how I did.
 
1 - 9 of 9 Posts
Top