1999 Pantera 580 EFI Fueling Issue - Seeking Input

3448 Views 25 Replies 6 Participants Last post by 660catman, 8 d ago

tjjhdad

Discussion Starter · Sep 5, 2021

Hello - New here and seeking some options on what to checkout next, situation as follows:

1999 Pantera 580 EFI with 2,512 miles
Started and ran great last season
Now the battery is junk, will be getting replaced
Also now can only get it to start and run for a brief time by putting fuel into the spark plug holes / cylinders
Fuel pump checks out ok

I thought this would / should run without the battery for the EFI but please correct me if I am mistaken. Also, is there some screen or filters that are ahead of the injectors I should be checking for blockage of fuel flow to the injectors? Lastly, any suggestions on the best source for downloading a PDF copy of the service manual?

Thank you in advanced for any input on this one.

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660catman

· #2 · Sep 5, 2021

If you didn’t prep the gas for summer storage you could have an issue with the gas itself. Also the injectors could be stuck closed. Tap them with a screwdriver handle a bit. The “smart” valves on fuel line in the tank could also be stuck closed. The only way to check them is with a fuel pump removal. With the small gas cap you wouldn’t be able to check them from there.
Sources for 99 models are hard to find. Country Cat has service manuals for 2000 and newer. It’s worth it to look there.

tjjhdad

Discussion Starter · #3 · Sep 5, 2021

660catman - Thank you for the response. Fuel was treated last year prior to being put in storage so assuming, for now, the fuel itself was / is ok yet. I am narrowing in on the "smart valves" as the potential issue but going to do your injector test first.

Noted and agreed on this year manual being a slight challenge to locate, some many of my searches on line are resulting in combined year service manual, perhaps that is all Cat provided and I just need to get one of those; I had assumed there was a specific to year and model of this sled service manual but I am usually wrong.

660catman

· #4 · Sep 5, 2021

The service manuals are under technical information and are year specific starting with year 2000. Also, did you run the treated fuel throughout the system? If you didn’t, pull line off fuel rail and turn sled over to get fresh gas in line. I’ll run mine a good ten minutes before shutting it down. Of course, watch engine temps.

ejowrench

· #5 · Oct 13, 2021

tjjhdad said:
Hello - New here and seeking some options on what to checkout next, situation as follows:

1999 Pantera 580 EFI with 2,512 miles

Started and ran great last season

Now the battery is junk, will be getting replaced

Also now can only get it to start and run for a brief time by putting fuel into the spark plug holes / cylinders

Fuel pump checks out ok

I thought this would / should run without the battery for the EFI but please correct me if I am mistaken. Also, is there some screen or filters that are ahead of the injectors I should be checking for blockage of fuel flow to the injectors? Lastly, any suggestions on the best source for downloading a PDF copy of the service manual?

Thank you in advanced for any input on this one.

If you suspect the injectors are not being activated, use a mechanics stethoscope on the injector body while someone pulls it over. Should here a sharp click, click, click.

FeelTheThunder

· #6 · Oct 31, 2021

You need a battery, it is not batteryless EFI

660catman

· #7 · Oct 31, 2021

FeelTheThunder said:
You need a battery, it is not batteryless EFI

I’m pretty sure Batteryless EFI came out in 97 on the ZR580 and some models in 98. It was in all 99 models.

ejowrench

· #8 · Nov 10, 2021

660catman said:
I’m pretty sure Batteryless EFI came out in 97 on the ZR580 and some models in 98. It was in all 99 models.

Yup. I have a 1999 Pantera 580 batteryless EFI . It has a battery, but only for the electric start. Stator does everything else!

Reactions: 1

davidson310

· #9 · 20 d ago

Were you able to get anywhere with the injectors? i have a similar issue, great spark, it turns over well, but if i pull the rail ( and turn it over) i get no fuel from either injector. I do not have any blink codes (until i disconnect either injector then it starts flashing, so i am assuming that my wiring is good to the injectors, I just dont know how to properly test the injectors to rule them out? They are cheap(ish) online but i would feel better knowing that i am not just throwing parts at this old of a machine

ejowrench

· #10 · 20 d ago

davidson310 said:
Were you able to get anywhere with the injectors? i have a similar issue, great spark, it turns over well, but if i pull the rail ( and turn it over) i get no fuel from either injector. I do not have any blink codes (until i disconnect either injector then it starts flashing, so i am assuming that my wiring is good to the injectors, I just dont know how to properly test the injectors to rule them out? They are cheap(ish) online but i would feel better knowing that i am not just throwing parts at this old of a machine

If your wiring is good, are your injectors clicking under a mechanics stethoscope when turning over engine? Don't buy cheap imitation injectors, you are just setting up yourself with more problems...

davidson310

· #11 · 20 d ago

ejowrench said:
If your wiring is good, are your injectors clicking under a mechanics stethoscope when turning over engine? Don't buy cheap imitation injectors, you are just setting up yourself with more problems...

I guess i am just assuming that my wiring is good because it faults out when i disconnect the injector from the harness

I will get ahold of a mechanics steshoscope and see what i can hear

auburn6887

· #12 · 14 d ago

davidson you have a 580 batteryless efi also?
does the sled run if you pour gas down the spark plug holes and reinstall the plugs?
do not assume.

davidson310

· #13 · 13 d ago (Edited)

ejowrench said:
If your wiring is good, are your injectors clicking under a mechanics stethoscope when turning over engine? Don't buy cheap imitation injectors, you are just setting up yourself with more problems...

My wiring is good, I have 12v to the hot wire 100% of the time ( ignition on and off?), and I have continuity to the ground ECM pin on the opposite wire, on both injector plugs. I connected everything back up and then confirmed with a stethoscope that I have no clicking while my engine is turning over. Resistance on both of my injectors is 2.0 ( the manual that i have is stating that the magneto powered EFI injectors should be in 2.46-3.34 range, however it is also stating that the injectors should be labeled with a square, circle, or triangle... and i am not seeing any markings like that? however i am seeing that the injector heads/tops are "yellow" which i believe is the determining factor on a efi system powered by battery... if that is the case, then the manual states the correct resistance is 1.53-2.07... so either i am in range OR I have bad injectors... can someone tell me what i am missing?

UPDATE: I have confirmed with this manual that my system is the Battery powered system, the ECU is mounted above the battery, and my ECU is shiny/silver. This means that my Injector Resistance should be in range of 1.53-2.07, and because they both test out at 2.0 I am going to go out on a limb and say that they are both (atleast resistance wise) good to go... i will do some bench tests with them to confirm function and check back in later with results

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davidson310

· #14 · 13 d ago

4

auburn6887 said:
davidson you have a 580 batteryless efi also?
does the sled run if you pour gas down the spark plug holes and reinstall the plugs?
do not assume.

The sled runs if I put fuel into the spark plug hole or if I run brake cleaner into the air induction box, but when the fuel runs out, the engine stops

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davidson310

· #15 · 13 d ago

Injector Function Update: I ran 5V DC to each injector in an attempt to make them function. I placed 5V positive to one terminal, and then i tapped the ground to the other terminal. Both injectors functioned properly. I then upped the amperage to 12Vdc, and repeated the process... both functioned as needed. I believe that i have eliminated the injectors as being the problem. I think i am now questioning the ECM not sending a ground signal to the injectors themselves, i will reinstall the injectors, and i will double check the test by having everything connected, and "tap" grounding the pins entering the ECM that i tested and confirmed continuity on before. If this tests properly I am thinking that i have ran myself into a wall? does anyone know what sensor sends signal to the ECM for it to understand/translate when and how much ground signal to send to the injectors?

660catman

· #16 · 12 d ago

Any flash codes on the ECU?

davidson310

· #17 · 12 d ago

660catman said:
Any flash codes on the ECU?

No flash codes, it flashes once when I turn on the key to confirm that it is working properly, and then it turns off.

It will flash if i have a low battery and am still trying to crank ( which is good)

It will flash if i disconnect either injectors ( which is good, showing that it is recognizing a short/ disconnect in the line)

I also confirmed that the "injector timing sensor" is what sends the signal to the ECM , and IF that sensor is faulty it would not throw a code (necessarily)... but it also would not send a signal to the ECM for top dead center location on the crank... if i am incorrect PLEASE let me know!

Also after speaking with a buddy, he said that i should look into the throttle position sensor, and doing a bypass on that ... but for some reason i was thinking that the TPS (if failed/failing) would cause a "no spark" issue... not a no fuel issue? Am i incorrect in thinking that the ECM pulls spark when there is an issue that is senses? ( again if i am incorrect PLEASE let me know... everything that i am use to dealing with this small is jet skis... so i am out of my realm a little bit with this one...)

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660catman

· #18 · 12 d ago

davidson310 said:
No flash codes, it flashes once when I turn on the key to confirm that it is working properly, and then it turns off.

It will flash if i have a low battery and am still trying to crank ( which is good)

It will flash if i disconnect either injectors ( which is good, showing that it is recognizing a short/ disconnect in the line)

I also confirmed that the "injector timing sensor" is what sends the signal to the ECM , and IF that sensor is faulty it would not throw a code (necessarily)... but it also would not send a signal to the ECM for top dead center location on the crank... if i am incorrect PLEASE let me know!

Also after speaking with a buddy, he said that i should look into the throttle position sensor, and doing a bypass on that ... but for some reason i was thinking that the TPS (if failed/failing) would cause a "no spark" issue... not a no fuel issue? Am i incorrect in thinking that the ECM pulls spark when there is an issue that is senses? ( again if i am incorrect PLEASE let me know... everything that i am use to dealing with this small is jet skis... so i am out of my realm a little bit with this one...)

Flash code is good then. I can’t find it in the parts listing but there should be an ignition timing sensor and injector timing sensor beside each other on the top of the crankcase. I have ohm readings in my service manual for a 93 Pantera 550 EFI. They are the same from 1993-1998. There’s other EFI component tests but those are for the battery EFI system. Yours is different.
You don’t bypass the TPS. You bypass the throttle safety switch aka TSS. A failing TPS will have no throttle response. It failed on my Pantera years ago. Corrosion got to it.
One note in my manual is checking voltage in the injector circuit should result in battery voltage. I would think you would only see voltage when running or turning over. I have no idea what voltage should be turning it over, assuming it gets 12+ running.

davidson310

· #19 · 12 d ago

660catman said:
One note in my manual is checking voltage in the injector circuit should result in battery voltage. I would think you would only see voltage when running or turning over. I have no idea what voltage should be turning it over, assuming it gets 12+ running.

Ok specifically for your/the comment above, when i unplug the injectors and test voltage on the harness i receive battery voltage 100% of the time ( with or without the ignition turned to on) is this correct?

I will reference this snip from my manual, but it states that the dropping resistor REDUCES voltage? ( I would think it would bring it from battery voltage down to like 5 volts or something like that?) but i am not seeing that occurring being that i am showing battery voltage all the time?

ALSO: my ECM does not have 2 plugs, it only has one plug... so the pictures and the diagrams are not quite correct?

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660catman

· #20 · 11 d ago

Not 100% sure on voltage should be at for your sled. That plug in bottom right of diagram is identical to my 93 SM picture. Those are for testing injector ground circuit. Shorting these to ground separately and each injector clicks, all is working. As far as dropping resistor, wiring harness, fuse link and injector. Injector and ignition sensors should have resistance of 190 ohms +/- 20%.

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