Fuel injector utube videos

[Guest Mike_s]

While lurking over at a corvette forum I came across several positive references to a rbanner at the injector connection along with some utube videos he has of injector bench tests. Long story short, I wound up buying a set of the bosch 3 type replacesments, hopefully for better gas mileage. If I ever get them in I'll pass on any worthwile results.

At any point I thought some of you might find the videos interesting,even with his company plugs

[D-a-n-i-e-l]

Great info on the injectors, have you done any research on what if any cars use ones that fit our 3800?

[handmedownreatta]

how much were the new injecters?

[Guest Mike_s]

The rebuilt Bosch 3's I'm gettng are for my 88 Reatta, the Reatta wasn't listed here http://fuelinjectorconnection.com/shop/index.php?_a=viewDoc&docId=7 so I sent Jon an email asking what he would recommend for a 1988 Reatta 3.8L "C", and he replied that "they have been using the Bosch design 3 19lb injectors in these buicks for a few years. They are also a drop in. no mods needed. $25. ea."

According to Jon 19lbs is the oem spec. I wanted somethng for better economy and driveabilty. If you want something more performance oriented for your supercharged Reatta maybe a higher lb injector would be better, but I'd guess that the fuel regulator and fuel pump specs may need to be evaluated to see if they could meet the higher fuel demand. I'd give Jon a email or call to discuss what your needs are.

So, to answer your question, no I'm not aware of any other cars which would have the 19lb bosch 3 injectors which would work in the Reattas. It would be nice to know though.

[Guest Jim Piro]

I have an 89 and I had mine rebuilt. They took all six and ran a flow test and then cleaned them, added new sccreens etc and retested them and sent the test results and the injectors for $15 each. I don't remember who did them but it was out west. I sent the results to Barney for his info.

[padgett]

My faulty memory says the stock L-67 injectors are 27 lb/hr but have seen mention of 36, 42, and even 60 lb/hr on drag cars.

The ECM will adjust according to the O2 sensor within limits once in closed loop but would probably be overrich in open loop and require reprogramming.

Keep in mind that the whole throttle body on the "L" and later 3800s has a lot higher flow than the "C" (LN-3).

[handmedownreatta]

im averaging 28 mpg,but more would be even better.

[Guest Mike_s]

I wrote this a month or so ago, sorry for the delay but I wanted to post some pics also, but that part keeps getting delayed so FWIW here it is.

I finally got to put in those rebuilt bosch 3 injectors that were shown in that fuel injector connection video I linked to a while back. I have to give them a qualified probably the most worthwhile $150 I've put into the car, short of brakes, I have to say qualified because I changed the injectors and other parts, and the injectors are not externally the same so they do not use the clips to hold them to the fuel rail which may be an issue.

I got the car about 3 years ago with 80k miles on it and was never really satisfied with it's performance even after changing plugs, wires, occasionaly using some techron injector cleaner, new o2 sensors etc, padgett's ignition upgrade helped and I recommend it. The car now has 150k miles and after changing the injectors and the items below its running much smoother and stronger as I ever remember it running, feels like a new car or did until the @#$%^&*() ignition switch rack in the steering wheel broke

I had wanted to do a better controlled test but one day the car started running really rough which turned out to be a very oil fouled spark plug on a relativly new plug, which resulted in replacing the valve stem oil seals. I also replaced the plugs and wires (which all appeared fine, execpt for the one foulded plug), a one year old pvc valve and it's twenty year old grommets (replaced the pvc valve because I've heard of some problems with non acdelco pvc valves on buicks), and I also replaced the fuel pressure regulator. I said quailfied because all of those items could affect the engine operation, as well as that there looked to be 3 different models of old injectors, 2 variants of the acdelcos and a what I think is a bosch type 2.

The bosch 3's are shorter than the orginal and bosch 2? injectors, the install instructions said to seat all of the injectors into the intake manifold and then to install the fuel rail, and to not use the clips connnectng the injector to the fuel rail. I was concerend that because the injectors were shorter (1/4?") and that because the clips were not used the injector may back out of the intake manifold. After installation with the fuel rail tightened down I could not move the injector away from the intake manifold, so maybe the clips aren't needed.

The engine revs and runs much smoother, accelerates quicker with less pedal, feels like a new engine, puts a grin on my face.

Gas mileage seems to be up, a 30 mile trip on the eastern shore of Maryland between Annapolis and Easton which is relativly flat and with a cruse controlled 55mph, synthetic blend oil, no ac, windows up and headlights down averaged 29.8, on the really flat part of the trip near the Chesapeak Bay Bridge read an avg of 31. On the return trip with the cruse cntrl off, mostly @ 55 mph, headlights up, some intermittent rain, the avg dropped to 28mpg.

If you're leary of the bosch 3's because of the difference in size and lack of clips, I'd suggest considering using some bosch 2's as they have a similar 4 hole nozzle vs the single port oem type. I can't say for sure that had I used matched clean replacement oem style injectors that the results would have been much less impressive, but my gut is telling me so, which is why I'll probably end up eating the AC delco injectors I bought right before I saw the injector videos.

Your results may vary depending upon your car's condition, but I'd make the change again.

[Fox W.]

I used this Bosch gen3s when I was troubleshooting a problem (seen here) and I've found despite what the guys at fuelinjectorconnection assure, me, the MPG is no longer accurate.   The MPG I would think is calculated by the BCM based on a statically defined pulse width time = x volume value, and the ECM lets the BCM know in real time how often and at what duration (pulse width) these injectors are on for.   That is my guess.. and if I'm right I'd say these injectors putting out more fuel for an equal pulse-width compared to the stock ones, which throws off the averages since the BCM would equate that shorter pulse-width to a lower volume than stock, even though the actual volume is the same.  

My MPG average drastically went up, the real-time and long-term average are both roughtly 7 or 8MPG higher always than what they used to be.  I do not think the injectors are actually just that much more efficient.  Based on actual consumption the MPG didn't improve.

 

Also I'm dealing with an issue where my exhaust smells strongly of unburned fuel since the above issue I linked and these new injectors.. I thought my converter having gone bad from what happened (Intake valve on a cyl was stuck closed for awhile, dumping extra fuel from the plenum in to other cylinders) but I've changed that now and it didn't fix it.  So I have to investigate what else..  If I must I'll go back to stock injectors and see.

 

Padgett Mentioned it could run rich before closed loop, though I get this odor even after closed loop.

 

Thanks.

[Ronnie]

I used this Bosch gen3s when I was troubleshooting a problem (seen here) and I've found despite what the guys at fuelinjectorconnection assure, me, the MPG is no longer accurate.   The MPG I would think is calculated by the BCM based on a statically defined pulse width time = x volume value, and the ECM lets the BCM know in real time how often and at what duration (pulse width) these injectors are on for.   That is my guess.. and if I'm right I'd say these injectors putting out more fuel for an equal pulse-width compared to the stock ones, which throws off the averages since the BCM would equate that shorter pulse-width to a lower volume than stock, even though the actual volume is the same.  

My MPG average drastically went up, the real-time and long-term average are both roughtly 7 or 8MPG higher always than what they used to be.  I do not think the injectors are actually just that much more efficient.  Based on actual consumption the MPG didn't improve.

 

Also I'm dealing with an issue where my exhaust smells strongly of unburned fuel since the above issue I linked and these new injectors.. I thought my converter having gone bad from what happened (Intake valve on a cyl was stuck closed for awhile, dumping extra fuel from the plenum in to other cylinders) but I've changed that now and it didn't fix it.  So I have to investigate what else..  If I must I'll go back to stock injectors and see.

 

Padgett Mentioned it could run rich before closed loop, though I get this odor even after closed loop.

 

Thanks.

I might agree that the fuel mileage would be calculated incorrectly by the BCM due to injectors with more flow but I can't understand why a larger injector would cause an overly rich mixture in closed loop. When in closed loop the ECM should be getting constant feedback from the O2 sensor and adjusting the pulse width to keep the fuel mixture at the optimum ratio for best engine performance. If the injector is spraying extra fuel the ECM should compensate for that based on what the O2 sensor is reading from the exhaust by adjusting the pulse width. If you are certain the engine is going into closed loop, you should check closely to make sure you don't have a bad O2 sensor. Have you changed it since you had the problem with the intake valve? Do you have any trouble codes stored?

[Fox W.]

I might agree that the fuel mileage would be calculated incorrectly by the BCM due to injectors with more flow but I can't understand why a larger injector would cause an overly rich mixture in closed loop. When in closed loop the ECM should be getting constant feedback from the O2 sensor and adjusting the pulse width to keep the fuel mixture at the optimum ratio for best engine performance. If the injector is spraying extra fuel the ECM should compensate for that based on what the O2 sensor is reading from the exhaust by adjusting the pulse width. If you are certain the engine is going into closed loop, you should check closely to make sure you don't have a bad O2 sensor. Have you changed it since you had the problem with the intake valve? Do you have any trouble codes stored?

 

I agree with you and I was only pointing at the injectors as one of the variables since it was new. My thought was more on intake-wall/plenum 'wetting' which will drip some after, as they don't spray a stream as much as they mist, and for some intakes a steam can actually be better.  

 

The MPG calculation is mostly what I wanted to mention here, it's just a thing to be aware of when changing to these.  I wish I could get a certain answer somewhere.. The guys at injectorconnection say I am wrong.  The onboard calculations say these injectors work miracles for MPG, while paper says no.

 

Yeah new O2 sensor was the last thing I did before calling it done, last one was kileld in the process.  Cat converter also killed.   It is going in to closed loop normally and I've been monitoring the O2 cross counts and voltage.. It all seems to be fairly normal, hits in to the rich range a bit more than other people (.9v) but only for instantaneous moments, it is changing very quickly as it should from there to as low as .13v.   

 

After running it for a few days I'm no longer sure there is a real problem, the exhaust smells pretty normal now. Is there a break-in period for these things?  I think the OEM cat somehow was a bit more effective before it was up to 600f, this one smells pretty raw till then.   Anyway I'm just going to get my smog check and we'll see it.  Last time with the suspected bad cat it almost didn't pass, where normally it passes with flying colors. 

 

The only other symptom is it seems slightly down on power, I had hoped a new cat would help that, but it didn't at all.

 

Thanks Ronnie. 

Edited September 6, 2015 by Fox W. (see edit history)

[NTX5467]

The "mist" seen in the videos is an indication of how much better atomization the newer injectors offer in their design.  These things evolve and become better as time  progresses, the design, that is.  In the intake manifold air, it's going to be anything but "still", as in the injector test stand, but have much velocity to it, which with the improved atomization, should provide a more homogenous air/fuel mixture toward the center of the air flow columns.  There will be "laminar" flow near the inner walls of the manifold and port in the cylinder head.  It has to be there to lessen turbulence and to help increase total flow, kind of like a buffer zone of sorts.

 

When I was first researching the computer controls (when they debuted at GM), the "open loop" operation used what was termed "a value" which would let the engine run well enough, then when "closed loop/feedback mode" happened, the computer varied settings as was needed to achieve emissions compliance and improved driveability.  I never did discover what constituted "a value", but I suspected it was part of the original "map", but I also suspect there was some variability to it as a map for Denver would probably be different than a map for Miami Beach, in open loop mode.

 

Of course, injector flow rate would need to be somewhat matched to engine ultimate horsepower output.  A prior formula, from the carburetor days, was .5lb/horsepower/hour.  Might be that with more efficient manifolding and fuel control, it might be a little less with injectors.  The designers/calibrators can trim the injector flow to finely-match power output or they can figure in a little more for possible engine modifications, but we never know that for sure.  I suspect this is one reason that some engines seemed to "test" better when all of the expanded ethanol fuel "conversion tests" were going on a few years ago (as greater amounts of greater-ethanol'd fuels were needed for the engine to operate correctly).

 

With the better-atomized fuel mixture, I can see where the engine would run nicer (as noted), but ultimate mpg might not increase very much in itself . . . unless the "less throttle to achieve a given acceleration to road speed" means the more-enriched portion of the fuel map is not ventured into results in less total fuel needed.  Another thing might be that the more-atomized fuel mixture can also tend to cool the mixture itself, which might add a few more horsepower for the same amount of fuel . . . might, in normal driving.

 

On the trip computers of cars I rented in 1990s, the Buick V-6s would only go to 67mpg "instant economy" during coast-down from highway speed.  Similar Chevy engines would go to 99mg in the same situation.  Toward the end of the 1990s, the Buicks would do the 99mpg level, too.  Never did figure out why the earlier ones only went to 67mpg and everybody else's went to 99mpg.  Unless it was an emissions calibration to prevent too much "stuff" during coast-down/closed throttle conditions, out of the tail pipe.  What did they change in the later years, though?  More mysteries!

 

NTX5467

[Guest Corvanti]

Fox, not disagreeing with all said, but with what Ronnie has informed folks in the past, the MPG screen is not entirely accurate.

 

without going thru all the old posts, i'd suggest a cleaning of the MAF with a proper cleaner. and probably more important, doing the "Seafoam" procedure for the fuel system as shown here: http://reattaowner.com/roj/component/content/article/67-engine-a-drivetrain/fuel-system/241-cleaning-the-fuel-system-with-seafoam 

[Ronnie]

The MPG displayed on the CRT is routinely 3-4 MPG less than if I calculate it by hand when I fill the tank  I think that is a bug in the early proms used in the '88 models like I have in my car. Don't know if other years calculate MPG correctly or not.