Bosch 0 280 155 811 Injectors

[thismachine13]

In case you Thought no one was interested......I’m following this thread.

[lummert]

If the AMM is adjusted to 004 ohms (380 ohms starting point) with Bosch White Giant injectors and 2.5 Bar fuel pressure regulator do I need to do anything with the ignition timing? I'm thinking that I need an LH 2.2 AMM for a PRV V6.

[lummert]

Swapping back to the 0 280 150 934 white-top injectors didn't go as planned. One of the injectors was dead. Swapped back to the 0 280 155 811 white giants. Swapped back to the 3 bar fuel pressure regulator and set the AMM to 004 Ohms (which is where it was set for the 2.5 bar fpr). Started it up and the AMM adjustment was close enough to use the LED tool.

Was researching the 0 280 155 811 white giants. They replace the 0 280 150 911 red-top injectors for Porsche 911. Specs for 0 280 150 911 are:

32.55 lbs/hr @ 45 psi
342.1 cc/min @ 3.1 bar

Curiously the 0 280 150 934 white-top and 0 280 155 811 white giants have the same specs at 3 bar:

29.3 lbs/hr @ 43.5 psi
307.9 cc/min @ 3 bar

[lummert]

Figured out how to modify pintle caps to work on Bosch GEN III injectors with recessed tips. Use the lower barrel of a Pilot G-2 gel pen. Press the pintle cap onto the threaded part of the barrel. Place used injector 0-ring onto pintle cap. Use belt sander to take the tip off the pintle cap down to the o-ring. Clean up the edge of the pintle cap. It's now ready to use on GEN III injector. Takes about 15 minutes per pintle cap.

Yesterday I made a run in windy, rainy, 55 degree conditions with my 88 765 on these injectors with the AMM set to 24 ohms. Averaged 19 MPG. Today I purchased new injector 0-rings. Next up is pulling injectors to install the pintle caps and new o-rings.

Next question is this...As long as I still have adjustment on the LH2.2 AMM do I need to add a resistor between the AMM and the ECM?

[lummert]

I checked the AMM between pins 2 and 3 with my multimeter and came up with 4.5 ohms. According to LH2.2/2.4 Fuel Management Information **Updated** from Bentley Manual the resistance between pins 2 and three should be:

LH2.2 3.5-4.0 Ohms
LH2.4 2.5-4.0 Ohms

According to this info my AMM resistance between pins 2 and 3 is off by 12.5%. Is this correct?

[thismachine13]

You may have already seen this web page but found some of the info interesting and Volvo specific.

http://people.physics.anu.edu.au/~am..._028050403.htm

"Larger Injectors on a 740 Turbo ?
A number of people have tried larger (eg. 370 cc/min (std 300)) injectors with little success using the standard LH-Jet 2.2 Turbo factory fuel computer and separate EZK ignition. It seems the engine sensor / mapping parameters cannot compensate enough for the increased injector flow and the system runs very rich both during idle and running - Probable reason for rich running - the computer still delivers the same mapped injector pulse width, it doesn't know your using a 66% larger injector. Bill Watson reports that at 11 psi boost in his 87 745, he measured no more than 82% duty cycle. Juha in Finland reports no rich problems with his B230ET model, but the ET uses an early Motronic system where ignition and EFI talk to each other.

Peter Linssen writes: Bosch / Volvo LH 2.2 cannot deal with injectors larger than 310cc. Bad idle and poor drivability is the result.
LH 2.4 however will adapt for injectors up to 370cc and offer good performance. However because the LH 2.4 system is adaptive it will trim itself to compensate for the richer mixture it offer very little if any advantage. If you want to run larger injectors with the stock fuel system you have to modify the signal from the MAF sensor to compensate."

[lummert]

Originally Posted by thismachine13

You may have already seen this web page but found some of the info interesting and Volvo specific.

http://people.physics.anu.edu.au/~am..._028050403.htm

"Larger Injectors on a 740 Turbo ?
A number of people have tried larger (eg. 370 cc/min (std 300)) injectors with little success using the standard LH-Jet 2.2 Turbo factory fuel computer and separate EZK ignition. It seems the engine sensor / mapping parameters cannot compensate enough for the increased injector flow and the system runs very rich both during idle and running - Probable reason for rich running - the computer still delivers the same mapped injector pulse width, it doesn't know your using a 66% larger injector. Bill Watson reports that at 11 psi boost in his 87 745, he measured no more than 82% duty cycle. Juha in Finland reports no rich problems with his B230ET model, but the ET uses an early Motronic system where ignition and EFI talk to each other.

Peter Linssen writes: Bosch / Volvo LH 2.2 cannot deal with injectors larger than 310cc. Bad idle and poor drivability is the result.
LH 2.4 however will adapt for injectors up to 370cc and offer good performance. However because the LH 2.4 system is adaptive it will trim itself to compensate for the richer mixture it offer very little if any advantage. If you want to run larger injectors with the stock fuel system you have to modify the signal from the MAF sensor to compensate."

Yes, I've read this.

[lummert]

Not a good idea to install Bosch GEN III injector using pintle caps. The injectors are shorter requiring a yellow spacer leaving no possibility to install the pintle caps. Installing the injector without using the yellow spacer possibly allows the fuel pressure to push the injector further into the intake manifold resulting in a fuel leak at the rail. I learned this yesterday when I tried to push the injector further into the intake with the engine running. The result was fuel spraying from the top o-ring.

Today I pulled the injectors, removed the pintle caps, and installed the yellow spacers (which were included in the pintle cap kits) on the bottom of each injector using the same new o-rings that I installed yesterday. The injectors now have a snug fit. The yellow spacers are 2.05 mm thick. So the spacer is 1 mm thinner than installing a second o-ring on the bottom of the injector.

[lummert]

Today I swapped the BMW engine temperature sensor [0 280 130 023] back to the correct OE sensor [0 280 130 026]. The engine then ran so rich that I couldn't adjust the AMM baseline idle setting. But now there were no cold start issues with this temp sensor. So to compensate for the rich idle mixture I swapped in the BMW 326e 2.5 Bar FPR. I was then able to adjust the AMM baseline setting.

So it seems that LH 2.2 will not run correctly on bigger injectors without lowering the fuel pressure.

[lummert]

Specification for the BMW 325e FPR is 38 psi.

[lummert]

0 280 155 811 specs from Bosch...
3.5 bar operating pressure
282 grams/min @ 3.5 bar
261.1 grams/min @ 3 bar
373 cc/min @ 3 bar
15* spray angle
8*-24* spray area amount
92 Design type
Jetronic electrical connector
No locating lug
O-rings standard
60.3 mm between 0-rings
73 mm total length

Original injectors are 75 mm total length. This is why the 2 mm spacers were needed.

0 280 155 811 injectors would flow 32 lbs/hr at 38 psi (337 cc/min at 2.65 bar).

[lummert]

Yesterday I tried advancing the ignition timing a bit. The idle improved. I then adjusted the AMM baseline setting until the LED was almost constantly lit, but still blinking. I then hooked up a vacuum gauge and turned the AMM screw clockwise to get the highest vacuum reading. Resistance between pins 2 and 6 of the AMM ended up at 345 Ohms, which is good being the starting point should be 375 Ohms.

Engine is running leaner as the interior of the muffler is more gray in color than previously.

This is all with 0 280 155 811 injectors from Buick 3800 Supercharged V6 and 0 280 160 225 2.5 Bar (38 psi?) fuel pressure regulator from 1987(?) BMW 325e (e being economy model).

[lummert]

Finally got the Schrader valve hose replaced on my fuel pressure tester. 0 280 160 225 - 2.5 Bar fuel pressure regulator from BMW 325e pressure test results:

39 psi w/o vacuum hose connected
30 psi w/ vacuum hose connected

These test results indicate that this BMW FPR's pressure specification is similar to Ford specs.

[Canadan]

Ive been running these injectors for years. Stock amm too. Just got a cheap Ebay adjustable regulator and made some bracket and fitting to adapt it to the factory rail. I can check the pressure its set at but im pretty sure its higher than 38 (i set it for full boost @wot and the wideband shows its happy everywhere else too). For spacers i was lazy and just used extra orings.

Now you mention it my mpg isnt awesome but it never has been. No working odometer so the effort is too great to get actual mpg numbers. All i know is boost makes me happy so burning gas to get there dont bother me.

[lummert]

These are my calculations:

0 280 155 811 injectors:
34.3 lbs/hr @ 43.5 psi
360.5 cc/min @ 3.0 bar

32.48 lbs/hr @ 39 psi
341.36 cc/min @ 2.7 bar

Idle pressure with 2.7 bar fpr: 30 psi
28.49 lb/hr @ 30 psi
299.4 cc/min @ 2.0 bar

If LH 2.2 AMM baseline setting is 375 ohms between pins 3 and 6, my calculations indicate that I need to have a baseline of 300 ohms. 300 ohms is what my current setting is:

Fuel flow increase of 20% (360.5/300=1.20)(+20%)
341.3/2.7=126.43
300.0/3.0=100
100/126.43=.79 (21% increase)

375 ohms baseline setting with 300 cc/min injectors @ 3 bar
300 ohms baseline setting with 341.36 cc/min injectors @ 2.7 bar

375(ohms)x0.80=300 ohms

Someone let me know if this makes no sense.

[Canadan]

Do you have any info on making one of those led tools? I remember a thread years back but 15 min on google and i cant find anything about making one just using one.

Cause you have me wondering now... i havent touched my amm and we have the same injectors (well basically, mine are 363@3bar). All i did was adapt an adjustable fpr to the rail and set that. Idles fine and afrs are perfect in boost and cruising so i didnt think anything of it.

Also amm adjustment only effects (affects?) Idle right? Or am i mistaken

[lummert]

Originally Posted by Canadan

Do you have any info on making one of those led tools? I remember a thread years back but 15 min on google and i cant find anything about making one just using one.

Cause you have me wondering now... i havent touched my amm and we have the same injectors (well basically, mine are 363@3bar). All i did was adapt an adjustable fpr to the rail and set that. Idles fine and afrs are perfect in boost and cruising so i didnt think anything of it.

Also amm adjustment only effects (affects?) Idle right? Or am i mistaken

I made my LED tool with a large 12 volt LED from Radio Shack. This LED has a built in resistor, so addingbresistors isn't needed. It has been my experience that adjusting the AMM pot screw effects more than just the isle mixture. I think you can find info on making your LED test tool by searching for LH 2.2 setting baseline isle mixture.

[lummert]

I used a dwell meter to check for injector duty-cycle using the 6 Cyclinder scale. got 21 degrees or 35% duty-cycle at idle. This is with adjusting the AMM pot screw to just a hair rich (LED constantly lit, turn counter-clockwise just a hair and the LED is on more than off) on the LED tool. Adjusting the AMM pot screw in or out has no effect on the dwell meter with the exception that the meter dithers at the same time that the LED blinks. Is 35% anywhere in the ball park? 30 degrees would be 50%, 39 degrees would be 65%, and 60 degrees would be 100% duty-cycle.

Specs that I find indicate latency (dead time) at 12 volts: 0.605 ms; 14 volts: 0.305 ms.

Pulse width of 0.605 ms @ 12 volts calculates to 0.38% duty cycle.
Pulse width of 0.305 ms @ 14 volts calculates to 0.19% duty cycle.

Some specs for Bosch
0 280 155 737
0 280 155 811
0 280 155 868
36 lb/hr @ 43.5 psi
380 cc/min @ 3 Bar
Gain: 0.12 ms/MG
Offset: 0.055 ms
Turn on time @ 14 vdc: 1.14 ms
Turn off time: 0.85 ms @ 3 Bar
Amperage: 1.0 amps
Pressure: Minimum: 30 psig; Maximum: 100 psig
Accuracy: 2.5%

[Canadan]

Okay sounds good, thanks.

One other question though. Why did you check dwell on the 6cyl scale for a 4cyl engine?





Edit for another question. You do have a fresh o2 sensor in there right? Cause otherwise all this adjustment is for naught. And thanks for the search suggestion i used those terms and found a schematic. Now to build one and try it out myself to see if our results correlate

[lummert]

Originally Posted by Canadan

Okay sounds good, thanks.

One other question though. Why did you check dwell on the 6cyl scale for a 4cyl engine?

My old dwell meter only has 6 and 8 cylinder scales. The 6 cylinder scale is easier to read than the 8 cylinder scale. Duty cycle conversion charts are available for 2,3,4,6,and 8 cyl. 50% duty cycle is 45* on a 4 cyl scale, 30* on a 6 cyl scale, and 22.5* on an 8 cyl scale. 100% duty cycle is 90* on a 4 cyl scale, 60* on a 6 cyl scale, and 45* on an 8 cyl scale. How many cylinders the engine has has to bearing in this case.




Edit for another question. You do have a fresh o2 sensor in there right? Cause otherwise all this adjustment is for naught. And thanks for the search suggestion i used those terms and found a schematic. Now to build one and try it out myself to see if our results correlate

I don't have a fresh O2 sensor, but I have 2 spare OE O2 sensors, The O2 sensor is switching, I've checked for that.

[Canadan]

Oh okay i got ya, carry on lummert ill join you when i get the chance. Probably this weekend cause now that i think about it, i quit driving that car cause mpg sucked idling in traffic to work every day. I figured i was just used to my 30mpg 1.8t but now youve got me thinking the idle mixture is just wrong.

[lummert]

Went out in the cold ass weather to check duty cycle using a higher quality KarCheck Dwell Meter, Clark engine analyzer, and LED tester. All 3 connected between the ECU test lead and battery positive.

Engine off/key off:
LED tester steadily lit:
5 volts steady
73.8* on 4 cylinder scale (calculated) = 82% duty cycle
49.5* on 6 cylinder scale = 82% duty cycle
37.0* on 8 cylinder scale = 82% duty cycle

Engine warm and in closed loop:
LED on more than off
5 volts on more than off
60* on 4 cylinder scale (calculated) = 67% duty cycle
40* on 6 cylinder scale = 67% duty cycle
30* on 8 cylinder scale = 67% duty cycle

Is this too rich? Should I try running same tests with 3 Bar FPR installed?

[Canadan]

Whats the factory duty cycle speced at? Me thinks you could divide the DC into your actual injector flow rate and compare that to the same calculation done with factory specs.

Or just get a wideband and youll know for sure of its too rich instead of all this black magic math and guesstimation.

[lummert]

Today I swapped back to the BMW 0 280 130 023 ETC.

Lowered the Idle duty cycle to 61% (36.5* on 6 cylinder scale, 27.5* on 8 cylinder scale) from 67%.

The engine off/key off duty cycle increased to 85% (51.0* on 6 cylinder scale, 38.0* on 8 cylinder scale).

I read on a Corvette forum that increasing fuel pressure will lower injector duty cycle. Since I'm running lower pressure 2.7 Bar (39 psi) FPR, I'm wondering if swapping back to the 3 Bar (43.5) FPR will lower the idle duty cycle. My calculations show that increasing the fuel pressure back to 3 Bar should lower the idle duty cycle to 55%.

[lummert]

Swapped back to Bosch 0 280 160 237 3.0 Bar fuel pressure regulator from 1989 Pontiac Turbo Trans Am.

Fuel pressure test:
40 PSI w/ vacuum hose connected
44 PSI w/o vacuum hose connected and plugged

Duty cycle results at idle in closed loop are:
54* on 4 cylinder scale = 60% duty cycle
36* on 6 cylinder scale = 60% duty cycle
27* on 8 cylinder scale = 60% duty cycle

Duty cycle with engine off:
72* on 4 cylinder scale = 80% duty cycle
48* on 6 cylinder scale = 80% duty cycle
36* on 8 cylinder scale = 80% duty cycle

Now to run wire from test point into the car to check duty cycle at about 6000 RPM.