Alternative Fuel Injectors

[safe]

I have 6 injectors from a Suzuki bike with unknown flow rates.
Can I flow them myself to see what I have?

[scarceller]

Jon,

I would always suggest servicing your stock 158 injectors first, I sent mine here:

Motor Man Fuel Injection Supply
Howard & Debbie Haack
6000 W. Weidman Rd.
Weidman, MI 48893
989-644-2695
989-621-9965 cell
fuelinjectorman@aim.com
http://www.fuelinjector.citymaker.com

Howard did a great job on my stock 158s and I'm using these freshly serviced injectors to setup my AFR. It has been a long road to setting up the AFR in my car. First I had a faulty FuelPressureRequlator that had my FP at 3.5 bar rather than 2.5. I have replaced the FPR and am now at stock 2.5bar FP. But when I fixed the FP the custom chip in my car was way to lean! So this caused me to dig in and learn the Chip maps and howto tune them. I have been tunning my AFR by burning new chips. Right now I'm finishing my WideOpenThrottle (WOT) map fine tuning, I have the 1000-5000RPM range spot on at 13.0 AFR and am now working on tuning the 5000-6800RPM range. I moved my rev limit to 6800RPM via the chip maps.

In order to do all the AFR recording I installed a WideBand O2 sensor and monitoring system in the car that feeds live AFR data as well as several other signals (like RPM) to a laptop. This allows me to run test runs on the road at WOT in 2nd gear from 1000RPM right up to rev limit of 6800RPM. Then I review the log and fine tune the WOT map. Then back to the road for another spin. It is very time consuming process but in the end I can really notice the diffrence in the car. Actually the log also contains time so I see the 2nd gear run getting faster since the first early runs.

I intend to put the 360 injectors in but not till I have AFR properly set with the 158s as a baseline. I just need more time.

If you are intrested in the details for installing a WideBand O2 sensor and monitoring system into a Carrera then see my other post:
Wide Band O2 + data logger for 84-89 Carrera
I actualy installed the WBO2 by piggy backing it onto the DME, I did not alter any wire harness in the car to do the install. But I did heavily modify the DME.

Originally Posted by Javers

Was any more work every done on this? Sal did you ever get a chance to verify your AF ratios? I'm debating whether to send my stock injectors away for servicing, or replace with one of the alternatives.

Jon

[scarceller]

Dfink,

I agree that in order to test an optional injector we MUST HAVE a baseline for the performance of the stock 158. This is why I'm tuning my chip with known good 158 injectors first, the goal of the tune is to obtain a 13.0AFR at WOT across the 1000-6800RPM range. Once the tune is done and the graphs recorded via my WideBandO2 I will put in the 360 injectors and record a simular run.

As for the 360 tip design and reduced heat soak, I only passed along the information I received from the Injector supplier that serviced my stock 158s and then provided me with the 360s for trial purpose.

[QUOTE=dfink;3587574][QUOTE=scarceller;3423976]the tip was redesigned by Bosch to help solve a heat soak issue that exists with the old plastic tip injectors. The issue is that while the injector is running the fuel keeps it cool but once you shutdown a hot engine the injectors heat soak quickly and any fuel left in/on the tip orfice quickly evaporates and leaves behind a film/particles that result in clogging if the engine exposed to short driving cycles. The idea behind the new metal tip is that the tip was designed as a heat sink to help reduce this problem.

I hate to even get back into this one but. Above makes no sense. You turn off a hot engine and no fuel is going to remain on either one for very dang long. The different tip produces a different spray pattern that would have been designed for a particlular combustion chamber in what ever car it was made for. Not that it wouldn't put fuel in the cylinder and make the car run and maybe run fine. I just don't believe the explanation given. But I suppose stranger things have taken place.
I have since found several injectors that are close to the 158. Unless someone has access to the several different kinds and performs AF testing on each type in the same car we will probably never know the exact results of not using the original. I think there are probably more to the specs than just flow and Ohms. Things like the maximum cycle time for it to open and close. Time between failure. Resistance to tempurature. All items that have not been discussed in this thread. I however admit that modern injectors may very well out perform the 20 year old technology that was state of the art at the time.
We know the original works as intended.
We Know some replacements appear to work and are cheaper
We don't know the under lying reasons of why one injector is chosen over another for the original design. This is all great information and provides some options for the experimental types. Keep On Squirting

[Bill in OKC]

I replaced my injectors last weekend with the 159s from 5-O (thanks ianc) I was having a no-start problem and after 112K miles I thought what the heck. they probably need replacing anyway. I found the no-start problem but then immediately had a flat tire so I only got to drive ~40 miles.

[dfink]

scarceller;
sounds like a good plan. It will be interesting to see how they compare.

[scarceller]

Are your bike injectors Bosch? if so what number are they? I have large spec list for bosch injectors.

First they must be low impedance 2-3ohms coil resistance. They can not be the more popular 12ohm coils.

Originally Posted by safe

I have 6 injectors from a Suzuki bike with unknown flow rates.
Can I flow them myself to see what I have?

[84_Carrera]

I'm going to go through the thread & re-read all the details, but...

The V6 Taurus SHO (3.0L / 3.2L, 1989-1995) uses a 24 lb-hr low-impedance injector. I have sets of these sitting on the shelf, and they can be had used for about $20-$50 / set of six (not a for-sale, just stating what the typical market for a set runs in the SHO crowd)

I'll see if I can cross the specs in the Ford Shop Manual I have also. I know Bimmer guys have used the SHO injectors as an upgrade on certain models, FWIW.

There are pink tops (3.0L), which are slightly less than 24 lb/hr, and purples (3.2L) which are slightly more. The rail-side diameter is smaller than the generic Accels (which I used 48 lb-hr versions of for my 'charged SHO).

Attached is a photo, haven't pulled a 911 injector yet, so I don't know how it compares.

[safe]

Originally Posted by scarceller

Are your bike injectors Bosch? if so what number are they? I have large spec list for bosch injectors.

First they must be low impedance 2-3ohms coil resistance. They can not be the more popular 12ohm coils.

No, they are Denso and there is no partnumber or markings at all, exept the Denso.
They are going on a 3.2, but not a motronic.

[stlrj]

Originally Posted by scarceller

First they must be low impedance 2-3ohms coil resistance. They can not be the more popular 12ohm coils.

Not necessarily. The rule of thumb is that you can always use high impedance injectors in place of low impedance and it will not hurt the ECM but you cannot substitute low impedance injectors for a system designed for high impedance injectors.

I have experimented with many different saturated injectors with different flow rates and have come to the conclusion that the stock injectors are (believe it or not) too big for good throttle response and, in reality, tend to bog performance throughout the rpm range. So far the injectors that work best and really wake up my 86 3.2 are GM Multecs that are found on Chevy 3.1 V6 engines. The have a superior spray pattern than the stock pintel type Bosch injectors, so they idle much smoother and have more than enough flow on the top end to convince my seat dyno.






Which also happens to be the same injector design with a four hole director plate that is currently being used on the 996 M96/03 engine.


The only other modification needed to make the saturated injector work on the 3.2 engine is a start relay for additional fuel for warm starts.

Cheers,

Jose'

[alniki]

Jose,

Your comments are pretty interesting and makes me want to try out the GM Multecs.
Could you deliberate on the reason for a start relay and how to do it? Thanks!

[stlrj]

The purpose of the start relay is to compensate for the higher impedance of the GM injectors, because without the relay, the engine will not get enough fuel to start when warm.

I wired the relay by grounding #85, yellow (#50) ignition starter wire to #86, CHT input on #30, CHT output on #87a and a 1K resistor between #30 and #87a.

Meanwhile, I have replaced the GM Multecs with a set of injectors from a 3.3 V6 Dodge Grand Caravan and am finding that these injectors work even better than the Multecs.

Cheers,

Jose' ( orighinally from the Philippines )
74 911 w/86 3.2 & Mopar injectors

[Javers]

Interesting stuff Jose, do you have the ability to log your AFR's to see how the different injectors are affecting your mixtures?

Jon

[stlrj]

No, just my nose up the tailpipe which turns out quite accurrate along with a very sensitive seat dyno.

[alniki]

Jose, you seem to be an expert at this.

Is the 'start relay' just a modification of the DME relay without installing an additional relay?

[stlrj]

Originally Posted by alniki

Jose, you seem to be an expert at this.

Is the 'start relay' just a modification of the DME relay without installing an additional relay?

If an expert is one who has made more mistakes than someone else, then I might qualify.

The start relay is an additional relay that I mount on the left side fire wall near the fuel filter. I'll post a picture soon.

Jose

[scarceller]

Jose,

I have been toying with difrent injectors as well. But my car has a a Wide Band O2 sensor and complete monitoring system. It allows me to fully record AFR, RPM, Throttle Position Switch and Air Flow Meter signal and anylize all these against each other.

See this thread for my WBo2 setup:
Wide Band O2 + data logger for 84-89 Carrera

Bottom line is I have a well tuned Carrera EURO 3.2L that has a custom chip also has stock 159 injectors, I know exactly what my AFR curve looks like at WOT with the stock injectors. I also know what my AFR is at idle. This means I can install any injector and compare it against others. I have done a little of this so far with not excellent results.

But I'm very intrested in talking to you about your high impedance results and maybe even trying a set of high impedance injectors. I have a good source for injectors that I can obtain them on loan.

Please contact me via PM with phone number so we may chat.

Thanks.

Originally Posted by stlrj

Not necessarily. The rule of thumb is that you can always use high impedance injectors in place of low impedance and it will not hurt the ECM but you cannot substitute low impedance injectors for a system designed for high impedance injectors.

Jose'

[dfink]

Originally Posted by scarceller

Jose,

I have been toying with difrent injectors as well. But my car has a a Wide Band O2 sensor and complete monitoring system. It allows me to fully record AFR, RPM, Throttle Position Switch and Air Flow Meter signal and anylize all these against each other.

See this thread for my WBo2 setup:
Wide Band O2 + data logger for 84-89 Carrera

Bottom line is I have a well tuned Carrera EURO 3.2L that has a custom chip also has stock 159 injectors, I know exactly what my AFR curve looks like at WOT with the stock injectors. I also know what my AFR is at idle. This means I can install any injector and compare it against others. I have done a little of this so far with not excellent results.

But I'm very intrested in talking to you about your high impedance results and maybe even trying a set of high impedance injectors. I have a good source for injectors that I can obtain them on loan.

Please contact me via PM with phone number so we may chat.

Thanks.

Now we're gettin somewhere. Actual testing........

[scarceller]

Jose,

I just finished reviewing the drive circuitry that drives the injectors in the DME, turns out you are correct you can drive high impedance injectors without doing any harm to the DME.

The 6 injectors are ALL driven by one signal that is a pulsed duty cycle ground signal. This means all injectors have a constant 12volts on one wire and then the other wire is pulsed to ground and the pulse width varies to increase or decrease fuel spray.

The driver for this signal is a Darlington type NPN transistor part #RBDT65A and the device is good for 12amps current. So if low impeadance injectors at worse case are 2.3 ohms then 6 of them in parallel would equal 0.38 ohms for a total current draw of about 32amps at 12v or about 39 amps at 14.7V. But of course you would only draw that much current if you applied a solid ground to one side and 12v to the other. But these injectors are duty cycle driven and the current is never that high.

Now most high impedeance injectors are 12 ohms or above for a total of 2ohms if you have 6 in parallel. These would only draw 6 amps substatially less than the 39 amps of the low impeadance injectors.

For these reasons I agree that you run no risk of damaging the DME box with hi-impeadance injectors.

Do they run the same? I'm not sure, we would need to test the results with WBo2 monitor. But Jose already has confirmed that the car runs and seems to run well.

here is the injector drive circuit right from the DME schematics:


Jose, one other question: I'm a little confused about how you are using the relay you mention to drive the injectors during startup. Could you draw a schematic of this and post it.

Or try to explain what exactly this relay is doing to the injector drive line? These injectors already have 12V on one leg during crank and running. So what does this relay do?

Are you just trying to fool the DME to think the engine is cold by disconnecting the CHT sensor line? is that the idea?

Thanks.

[rvanderpyl]

Originally Posted by safe

I have 6 injectors from a Suzuki bike with unknown flow rates.
Can I flow them myself to see what I have?

Have a look here, ytou might find some info
http://www.msefi.com/viewtopic.php?t=2576

[dfink]

Originally Posted by scarceller

Jose,

I just finished reviewing the drive circuitry that drives the injectors in the DME, turns out you are correct you can drive high impedance injectors without doing any harm to the DME.

The 6 injectors are ALL driven by one signal that is a pulsed duty cycle ground signal. This means all injectors have a constant 12volts on one wire and then the other wire is pulsed to ground and the pulse width varies to increase or decrease fuel spray.

The driver for this signal is a Darlington type NPN transistor part #RBDT65A and the device is good for 12amps current. So if low impeadance injectors at worse case are 2.3 ohms then 6 of them in parallel would equal 0.38 ohms for a total current draw of about 32amps at 12v or about 39 amps at 14.7V. But of course you would only draw that much current if you applied a solid ground to one side and 12v to the other. But these injectors are duty cycle driven and the current is never that high.

Now most high impedeance injectors are 12 ohms or above for a total of 2ohms if you have 6 in parallel. These would only draw 6 amps substatially less than the 39 amps of the low impeadance injectors.

For these reasons I agree that you run no risk of damaging the DME box with hi-impeadance injectors.

Do they run the same? I'm not sure, we would need to test the results with WBo2 monitor. But Jose already has confirmed that the car runs and seems to run well.

here is the injector drive circuit right from the DME schematics:


Jose, one other question: I'm a little confused about how you are using the relay you mention to drive the injectors during startup. Could you draw a schematic of this and post it.

Or try to explain what exactly this relay is doing to the injector drive line? These injectors already have 12V on one leg during crank and running. So what does this relay do?

Are you just trying to fool the DME to think the engine is cold by disconnecting the CHT sensor line? is that the idea?

Thanks.

I have to disagree with your calculations. In this case you can not consider that there are 6 injectors in parallel because only one circuit at a time is being activated. Also because of the short frequency you would never see anywhere near that type of current draw. Granted the high impedance injectors are going to draw less current in a steady state. People say they work but have not tested with AFM. Keep in mind the original idea behind low impedance injectors. Hit the injector with a very high pulse to get it open quickly then back it off to modulate the correct flow. It all happens quickly but is still controlled. I doubt however that you would hurt the DME by installing the higher impedance injectors. Here looks to be a good look at current flow for different type injectors.

http://www.msdfuelinjection.com/ecu_compatibility.html