I was wondering if anyone knows what the output voltage to the pumps is supposed to be coming out of a Zone 5 MDM jr? I only have 4.2 volts at idle, which might be fine, but I'm not sure how the returnless systems work. I have fuel pressure fluctuation issues at WOT and not sure if my pumps are getting enough voltage from the MDM. Any help would be great.
Zone 5 MDM jr. voltage issue
- Thread starter jldecke
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That voltage definitely doesn't sound right at all, but I'm sure more people with experience in this area will chime in. Lucky for you zone 5 is out of business now...:rollseyes Someone else posted very recently about one of these failing with very low mileage on the unit.
I thought it sounded a little low too, but I'm not a expert at Ford Returnless fuel systems. I've also been trying to find a good wiring diagram for the Zone 5, but all I seem to find is people who have had problems with them. Thanks for the input.:rockon:
As I understand MDMs, they just match the voltage output of stock FPDMs with increased current capabilities.
That said, 4.2V@idle sounds about right. My guess is that your duty cycle is about 40% (reads .20 on a programmer). Did you check your duty cycle at idle?
That said, 4.2V@idle sounds about right. My guess is that your duty cycle is about 40% (reads .20 on a programmer). Did you check your duty cycle at idle?
No way for me to check the duty cycle right now, as I sold my X3 with my last Cobra and I am now waiting for a new one to arrive.
I am not surprised. I have talked to some tuners and saw first hand that there is a little more time involved with dialing in WOT in higher rpm's. Which sounds similar to OP issue. I assume from your posts that you didn't have it tuned after installing the MDM?
Just had it tuned on Monday and that's when we found the fuel delivery issue. I don't think there is any issue with the tuner, just the fact that I am having a 20psi variance in fuel pressure every couple hundred rpm after 3500. It's like a fuel pump is not getting enough voltage after this point, which was making me think that it is the FPDM or the MDMjr.
Just to be sure of what I just read.
Am I mistaken or are you using both the FPDM and the MDM Jr.?
Because the MDM Jr. is a box with two higher capacity FPDMs in it. You use one or the other, not both.
You can, however, use a BAP with the MDM Jr., or with two FPDMs.
Am I mistaken or are you using both the FPDM and the MDM Jr.?
Because the MDM Jr. is a box with two higher capacity FPDMs in it. You use one or the other, not both.
You can, however, use a BAP with the MDM Jr., or with two FPDMs.
Sorry, but you have been misinformed. An MDM runs inline between an FPDM and pumps.
New Product: Fuel Pump "MEGA Driver Module"mjchip said:
And that's what I get for posting too late at night. And I even went out to the filing cabinet in the garage and re-read the instructions from MJ on it.
I knew I shouldn't have stopped at the fridge on the way back to the computer.:shrug:
Thanks!
Take the MDM and throw it in the ocean...better place for it than in your car...biggest POS i ever bought
What was wrong with the one you had?
OP if you decide to go another route, don't throw it in the ocean. Sell it to me. I'd like one for a spare since Zone 5 is out of business. Mine has worked flawlessly for about a year and five thousand miles, but you never know.
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It's possible that I might get rid of the MDM jr. just because I have no info on it and they are now out of business and there is no support for them. I'm sure that they made a good product, but without being able to have some written info on it for me to be able to troubleshoot with, it will be replaced by a dual FPDM setup with a BAP.:rockon:
I have Ford GT pumps, Fore hat, 60lb injectors, and the Zone 5 MDM jr. The car is a KB 2.2 with 19lbs of boost.
Well, it's been awhile since I started this thread, but I just finally had time to work on the car. I replaced the Zone 5 and installed the Lethal Dual FPDM setup, but this still didn't fix the problem. I have checked or replaced just about everything in the fuel system and still have not found the issue. I am now just thinking about going to a Return system and forgetting about the headaches of the returnless system. I just ordered a new FRPS from Tousley and we will give it one more try, but it looks like Lethal will be getting a call in the near future. :shrug:
Sorry for the delayed response, my tuner finally found the problem with the car after I was totally fed up with it and had changed to a return style fuel system. Turns out the problem all along was a bad connection on the inline fuse feeding the fuel pumps that had been installed by the previous owner. That little headache was the root of all my problems. Good luck with your install and thanks to everyone for the advice on my problem.:beer:
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