Tune up day

Drcoffee

Drcoffee

Senior Member
This is a new to me 1999 SR5 with 158,000 miles on the clock. I had some time after pulling the rear drivers side axle because of a bad bearing causing gear oil to leak, so I decided to do a tune-up. I installed new NKG plugs and NGK wires, new O2 sensor, cleaned the throttle plate. Some joker had these plugs installed and used a totally different plug on #3. What gives with people. They go to all the trouble to change the plugs and can't even use the right parts.

These engines use a wasted sparked ignition and on 3 cylinders the spark is going in the reverse direction, from ground to electrode. These Quad Bosch are not even compatible for this system. I guess that could explain the poor gas mileage I was getting at around 14 mpg. Actually it felt more like 14 gpm.

ry%3D400
 
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The things some people will do just to get a vehicle to run. I bet it ran like crap before you took those out. Good luck!
 
Yikes!! :eek:

High Idle now. I started it up and it stayed around 1800 rpm. Then I shut it off and pulled the EFI relay (why that helps, I'm not quite sure) and disconnected the battery for 10 minutes. Started it up again and it idles near 1200 now. From what I have read it could be the IAC valve from when I sprayed the throttlebody valve with carb cleaner. I'll try again in the morning. Unfortunately, I can't drive it until I get the axle installed on Monday.
 
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Wow I just did the exact same thing. Pulled the plugs out and sure enough 5 Bosch platinum and one no name. It was yellow and I've never seen one like it before I Should of snapped a pic.
 
High Idle

I got the truck to idle again. I ended up pulling off the plastic intake tubing and gave a couple of squirts of MAF cleaner down the hole in front of the throttle plate. I left off the plastic intake tube and started the engine and it fired and then died. I did that 3 times. What I was hoping is that the cleaner would dissolve the carbon and then suck it past the IAC valve letting it function again and close. I was right. After reconnecting the plastic intake tube it fired up and the idle dropped to 750. I didn't have to remove the IAC either. Don't flood the hole, just two quick shots of MAF cleaner should dissolve any crud.

The reason I used MAF cleaner is it doesn't leave a residue and is less aggressive than carb cleaner.

I hope this proves to be an easier fix for this problem.
 
LittleCaesar said:
Did you clean the MAF?
Click to expand...

I sure did and it had no affect on the idle problem. I believe the problem happens when you spray the throttle plate with cleaner and the carbon flows right down into the hole to the IAC. In my case, I don't think the TB was ever cleaned, just by how much carbon had built up.

This problem acts just as if you had a massive vacuum leak
 
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Drcoffee said:
This is a new to me 1999 SR5 with 158,000 miles on the clock. I had some time after pulling the rear drivers side axle because of a bad bearing causing gear oil to leak, so I decided to do a tune-up. I installed new NKG plugs and NGK wires, new O2 sensor, cleaned the throttle plate. Some joker had these plugs installed and used a totally different plug on #3. What gives with people. They go to all the trouble to change the plugs and can't even use the right parts.

These engines use a wasted sparked ignition and on 3 cylinders the spark is going in the reverse direction, from ground to electrode. These Quad Bosch are not even compatible for this system. I guess that could explain the poor gas mileage I was getting at around 14 mpg. Actually it felt more like 14 gpm.

ry%3D400
Click to expand...

Thats freaking rediculous. Why wouldnt they just pull all the plugs?
 
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