Resolved Testing Omni 4 bar to see if it's bad?

[TSI_too_slow]

Good morning all. I am terrible with DSMLink & electrical diagnosis but here we go.

I believe my Omni 4 Bar map sensor is bad. How can I test the sensor? I don't have a mechanical gauge to check the reading my 4bar shows on DSMLink vs what it truly is.

When cranking it reads -28.9. what should a good baseline be? What is the voltage the sensor should be putting out? (KOEO) and when cranking? I have my 5v reference at the sensor, it tests at .33v (KOEO) when cranking it stays near .3.

What is the voltage suppose to be at the sensor? How much voltage should I have at the connector to the sensor?

Thanks in advance everybody!

 

[MattHDSM]

I had a similar problem with an Omni 4 Bar awhile ago, here's a copy/paste of mine from a different thread for the sensor via pressure testing.

While connected to link, you’ll want to watch what kind of pressures it reads. Most easily you can check with engine off, key on, you should see atmospheric pressure (0.0 psi). If you see -29.8 inHg, link is seeing the sensor as disconnected. Make sure the connections are secure and fiddle with the sensor and wiring just to rule out a poor connection or bad wiring.

Going a little further than that, you can pressurize the system using a boost leak tester and compare the values. If you just want to do a quick check without disconnecting much, you can try to pressurize the sensor with just your mouth and watching on link what happens when you suck vs blow. For a GM-style, just use the vacuum line as if it’s a straw, for a Mitsu-style you’ll need to wrap your mouth around it it’s quick and dirty but it’ll let you know whether something is up.

 

[Mello]

OMNI doesn't make their sensors. They are GM/Delphi sensors. This link has all the info for the different MAP sensor data sheets.
http://www.robietherobot.com/storm/mapsensor.htm

MAP sensor should read atmosphere at key on before starting. You can use a vacuum pump to check below atmosphere & compressed air for above, remove it from the intake, add a piece of vacuum hose & connect it to a pressure &/or vacuum source while watching the sensor output.

OMNI sensors go bad a lot & have a terrible reliability problem. You should consider getting a better quality sensor.

 

[TSI_too_slow]

@Mello Thank you for your response. I was thinking Omni did make their own. I just ordered a GM 4 bar thinking that was an upgrade from the Omni due to seeing their poor quality reviews.

@MattHDSM thanks for the check. I'll comb through it in the next few days & see. I'm still new to DSMLink, I've got a good friend with a history of DSMs show me how to navigate it. So I'll relay that info to him & see what sprouts.

 

[92AWDHX40]

AEM MAP bar sensor, I'm going to run one but, for now I have a spare Omni just in case.

 

[Vegas Smith]

It's incredible how many people run those things with their failure rate.

 

[Mello]

I run an AEM 5-bar for the past 15 years never had a problem & installed it like this

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[jakk220]

Had the same issue before as have many others. The sensors fail for whatever reason. I have seemed to have more luck running the adapter and mounting the sensor on the firewall instead of directly on the intake manifold.

There was a bad batch that went out a while ago. I assume it was quite a few of them too.

I messaged Omni about my issue a while back and they said they fixed the issue and sent me a new one for free no questions asked. Shoot them a.message and im sure they won't have any issues replacing it for you.

 

[NOSLO2PT0]

I run an AEM 5-bar for the past 15 years never had a problem & installed it like this

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How much are the AEM 5 bar sensors? I like that mounting setup. Out of the way and solid.

 

[Mello]

How much are the AEM 5 bar sensors?

I don't sell these. Maybe search some of our supporting vendors listed below???

 

[TSI_too_slow]

@Vegas Smith I agree! That shocks me that many people that have had issues have said "I'll just buy another one" as if its a part with a regular life expectancy.

I'm going to try this GM I currently have on order & see about getting the Omni warrantied as a back up. I don't see too many GM 4 bars being ran, it'll be a trial & error I'm sure. Definitely ready to finally cruise this thing and enjoy.

@jakk220 Mine was mounted on the firewall as you stated. That does seem to be the ideal place for it.

While I have you knowledgeable folk here, before I post a newb question I couldn't find the answer for, anybody have a link or answer? If the new MAP corrects my issues I plan on driving the Talon for a month then installing my flex fuel sensor and switching to E85.

Q: What are the detailed parts I WANT/NEED to have to monitor the car while running E85?
I'm bumping my injectors up from 1050 FIC to 1650 FIC & having it retuned. I have my Wally 450, continental flex fuel sensor and harness. Is there a "best" option for the alcohol content gauge? I want to make sure I'm not missing anything when I make the switch.

 

[92AWDHX40]

I just use my ECMLink log to log the ethanol content. I just installed mine and I'm doing a new build so I can't log it yet but that's what works for me.

 

[TSI_too_slow]

@iugrad92turbo That's what a buddy of mine said to do as well. I don't have my own personal tablet or
anything to watch all the parameters. just my 3 main gages in the pillar. sounds like the most accurate way to go though. wish I could find a compatible double din to do everything right there on the display.

 

[TSI_too_slow]

After replacing the MAF based solely off of the .33 V it had vs the 1.15V spec I found. The car does run!

Problem solved. Thanks for the input & ideas guys!

 

[Red 1g talon]

After replacing the MAF based solely off of the .33 V it had vs the 1.15V spec I found. The car does run!

Problem solved. Thanks for the input & ideas guys!

Can you elaborate? What do you mean replaced the maf ?