HG/head milled .010/fuel injectors cleaned - done. (1 Viewer)

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Well, Bessie is back on the road in style! Finished bolting things together and we put the hood back on this afternoon. Put a flush in the cooling system and took her for a drive after retiming to 7 degrees of advance as I've been running for 5 years (stock is 3).

Unbelievably quiet and dead smooth at idle. I honestly don't think it idled like this when new, but I'm sure it did. The throttle body got a serious cleaning at the same time, so some of this is surely due to the clean throttle valve edges and seat.

As noted, I also had the fuel injectors professionally cleaned by a shop here that mirrors RC Engineering's offering. Graphed flow, cleaned, disassembled and the post flow - all on a chart for me. Now they all flow at 77 (not here to see what that volume is).

Since all the cables were off (cruise, tranny, throttle) I carefully felt them to see if I could feel what the roughness has been for years. I lubed the throttle (to gas pedal) cable once years ago with graphite with no success. Now I can clearly feel it's the tranny cable that's rough, so I lubed it as well.

The difference is substantial from the driver's seat. It starts instantly vs a revolution or three. It has notably more throttle response. But most significantly that 'sluggish' feeling this truck has had compared to the 97 I got it a year ago is gone. It now has the same light and crisp feel when accelerating from a roll, and it seems to need less throttle to get the same acceleration. Most of this would be expected from the throttle body cleaning and head work, so nothing earth shaking, but I'm grinning about it and very pleased.

I ran some errands with water and the cooling system flush in it, then came home and flushed it with hot water from the hose and refilled with Red and distilled water. Restarted and topped it off, then drove around the block and back into the garage for a hot drain of the oil and fresh filter along with crappy NAPA oil which I'll run for a couple months and drain. Makes me feel wierd - first non synthetic in this engine since it shipped from Araco in 1993!

Overall, I could not be happier with this improvement. I will post HG pictures here in this thread later.

I have a few additional tips that will go out in the tip sheet that goes with each DVD and I'll also post them here and email to folks who already have one.
 
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I bet the injector cleaning and mapping had to help out w/ starting issues and driveability. Definitely want to see some pics. How did the flow compare on paper to before?
 

scottm

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Good job, bro. I'm almost motivated to clean my intake. Tonight three of my four cars were all down with minor problems, I think I'll let it be for now.
 
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Cabron,

I don't know what the units of measure are (cc/min?) but here's the data:

No leaking injectors, all 13.8 or 13.7 OHMs, spray pattern Good (best), all internal screens clean. Flows are as follows by cylinder (before/after):

1 - 74/77
2 - 73/77
3 - 75/77
4 - 75/77
5 - 75/77
6 - 75/77

Scott - let me guess. The Subaru was the only one moving, right? My Legacy never needed anything and never stopped moving.

DougM
 

C6H12O6

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77 cc/min would be a buttload of gas. If that is the unit they're measuring in, there is no way that is the actual on-the-vehicle flow under normal load. Even at WOT, there's no way.

77 mL of gas pumping through each injector, every minute, would empty a 25 gal tank in about 16.75 minutes. These things get crappy mileage, but not THAT crappy.
 
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Steve,

I'm not sure that it's flowed in the same way it is flowed in actual use on your car. By that, I mean they could use some standard test pressure that's different from the vehicle, they could have the injector constantly open rather than pulsed as it is on the vehicle, etc. These would remove variables that occur on the car such as RPM, etc. Heck, they may not even use gasoline through them - could be something with a different viscosity.

At any rate, there are auto fuel injectors that flow over 1000 cc/min so it seems like a lot but remember this is likely some standardized flow test protocol not intended to duplicate conditions in the vehicle, but to provide enough variance in injector flow to make conclusions as to condition, etc.

DougM
 

C6H12O6

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Yeah, that's what I was trying to point out. Could very well be the test flow under bench conditions, but not on-the-truck flow.

Good point about it being full-open and not pulsed. That would make sense.

Cool write-ups on this project throughout. I'm thinking of doing the injectors this summer. Any tips on what to ask for when looking for a local shop to do the work?

Thanks,
Steve
 
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77 is probably the 15 second flow rate in cc. Stock fzj80 fuel injectors in spec can flow from 266 to 352 cc/minute. 6 injectors flowing 308 cc/minute would consume just a bit more than 29 gallons in an hour.
 
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C6H12O6

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Rich said:
77 is probably the 15 second flow rate in cc. Stock fzj80 fuel injectors in spec can flow from 266 to 352 cc/minute. 6 injectors flowing 308 cc/minute would consume just a bit more than 29 gallons in an hour.


Not that it's a big deal, but where are you getting the 29 gallons in an hour? 6 injectors flowing 308 cc would be 1848 cc (or mL) per minute. 25 gallons is roughly equal to 7571 mL. I only get 4 minutes at that flow.
 
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C6H12O6 said:
6 injectors flowing 308 cc would be 1848 cc (or mL) per minute.

C'mon Steve - I can't believe you let us down on the significant figures. Your students would give you a tongue lashing over this!:grinpimp:


:popcorn:
 
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C6H12O6

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My bad. I did what I tell kids not to do. I punched a number into the computer and didn't question what the answer was. I knew 1 gallon is about 3.78L. For some reason, my Mac OSX dashboard widget converter gave me the wrong conversion. 25 gallons converted to 7.57 liters. :doh:

With the correct conversion, MY calculations show that 25 gallons would only last a shade over 51 minutes, or, uh, um... just a bit more than 29 gallons in an hour.

I am such a moron. :rolleyes:

I salute you, Rich.
 

C6H12O6

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syrinxstar said:
C'mon Steve - I can't believe you let us down on the significant figures. Your students would give you a tongue lashing over this!:grinpimp:

My DREAM students would lash me for this. My REAL students can barely multiply. :crybaby:

Thanks, No Child Gets A Dime.
 
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I don't see why you can't blame Steve Jobs. I blame Bill Gates all the time.
 

C6H12O6

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Rich said:
I don't see why you can't blame Steve Jobs. I blame Bill Gates all the time.


For some reason, "25" converted to 7.5708, whereas 25.0 converted to 94.635. Go figure. Like I said, I should have noticed that 7.5708 was nowhere near what it should have been. Oh well. I'll do what I do for my kids when they catch me in a mistake: one extra credit point for you. :D
 
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Glad to see you guys have the math thing down - heh. As I've heard and try to heed "Never do math in public".

Well, I did the first cold start this morning and was downright blown away. My 93 has started and revved to 1300-1500 since new. I remember that mine always revved more than other 93 because I also drove them for work now and again.

But this morning, it went only to about 900 or so. I didn't notice the peak as I was too astonished by this next part. When I turned the key, it literally fired up instantly - like less than a second and it was running. Normally, it takes at least 3 times as long to start. I'm wondering how long this will go on, but hopeful.

DougM
 

cruiserdan

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The 900 sounds low and is indicitve of a vehicle that has not been through enough start cycles after having the battery disconnected. How's the hot idle?
 
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Hot idle's fine - spot on 650 like it has never been (generally 576-600). Absolutely rock steady. Good point on getting the cycles to fully redo the defaults. I'm liking this behavior, though. Very relaxing startup.

DougM
 
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Dan,

You're right. My truck's been starting in the 1800-1900 range and now it's starting in the 1400-1500 range from dead cold. Was just looking at my log and just got back from another cold start so I made a point of watching the peak RPM on startup. Those 400 RPM's make a huge difference in not only the ruckus of the startup, but also the shift shock when you have to put the truck in gear. Now feels more natural and unstressed.

DougM
 

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