Fuel issues, stumbling misfiring, 320hp Omni

[BoostedDrummer]

I have a 3bar MAP from Cindy, I decided to try to bypass the baro solenoid by connecting the MAP directly to manifold pressure/vacuum. The engine still bogs and starts/dies immediately..

[tryingbe]

What other diagnostic things have you try?
Plug a scanner in and read the map voltage?
Do a vacuum/boost leak check?
Do a fuel flow check?


Throwing parts in without diagnosis the problem first, is just that, throwing parts in.

[BoostedDrummer]

What scanner? All I have is a multi meter

Haven't checked boost or vac leak, I would try to test fuel flow but my fuel rail doesn't have a schrader valve to hook a guage up p to

[rx2mazda]

LOL, IDGAF!

What scanner? All I have is a multi meter

Haven't checked boost or vac leak, I would try to test fuel flow but my fuel rail doesn't have a schrader valve to hook a guage up p to

You don't need a schrader valve....http://www.harborfreight.com/fuel-in...ter-92699.html

[acannell]

fuel problems destroyed your O2 sensor? part-throttle = closed loop so bad O2 sensor = stumbling, full throttle = O2 sensor ignored so everything okay?

[BoostedDrummer]

Think I should unplug it to see? Btw, i saw that intake you built. Very nice!

[acannell]

Think I should unplug it to see? Btw, i saw that intake you built. Very nice!

Thanks!!

Is your setup using the stock O2 for the ECU or are you using your widebands narrow output for it?

I'd just scrutinize whatever the ECU is using for O2 feedback. If you have a multimeter you could put it across the O2 sensor output leads at idle once its warmed up and is using the O2 for feedback, and you should see it bouncing around. That probably indicates its okay at part throttle, even though you are just testing it at idle. Careful around the O2 sensor area..the power steering pulley is deceptively close and you dont want to end up one armed..maybe get your multimeter hooked up to the O2 sensor before you even start the car.

- - - Updated - - -

on the other hand..an obviously failing O2 sensor should trigger an ECU code

BUT

if the map sensor is failing (are you getting code 13?) then I dont see how it can maintain those normal AFR's at WOT

[BoostedDrummer]

I need to get used to this tapatalk app on my phone, I haven't figured out how to quote posts through it.

In response to rx2mazda: I feel like an idiot lol, I'm gonna have to go buy one

At acannell: I am pulling a code 13. I looked it up and it said on the mini mopar site that it could be the baro solenoid, so I bypassed it by hooking the map up directly to a vac source, no change to the way it runs. The o2 is a 4 wire setup and going through a wideband AEM guage.

I checked the grounds around the motor (passenger side at front of head to mount, intake to firewall, both grounds on the driver side of engine, etc) and they are all solid

[acannell]

The o2 is a 4 wire setup and going through a wideband AEM guage.

So you have the stock 4 wire O2 sensor connected directly to the ECU, and a second wideband O2 sensor for the wideband right? Or what did you mean by the above?

[tryingbe]

I would try to test fuel flow but my fuel rail doesn't have a schrader valve to hook a guage up p to

No gauge needed.

http://www.turbo-mopar.com/forums/sh...=1#post1052258

[BoostedDrummer]

I will take a video when I get home from work of the setup on the car all you can get a good visual on everything. I went to bed early since I had PT at 0400 this morning.. I'm tired! Lol

[glhs727]

I need to get used to this tapatalk app on my phone, I haven't figured out how to quote posts through it.

In response to rx2mazda: I feel like an idiot lol, I'm gonna have to go buy one

At acannell: I am pulling a code 13. I looked it up and it said on the mini mopar site that it could be the baro solenoid, so I bypassed it by hooking the map up directly to a vac source, no change to the way it runs. The o2 is a 4 wire setup and going through a wideband AEM guage.

I checked the grounds around the motor (passenger side at front of head to mount, intake to firewall, both grounds on the driver side of engine, etc) and they are all solid

code 13 is vacuum to map. it can also be a bad map, bad vacuum to map, (check to make sure the map is getting vacuum by checking lines etc...) Normally when you set a code 13, the car will run pig rich so it is a possibility that you also toasted the O2, but you won't know that until you fix the code 13

[BoostedDrummer]

I'll check all the lines running to the MAP once I'm off work. If it's bad, how much for another 3bar? I really am not fond of pulling the o2 sensor as it's a pain to get to, but I will pull it to see how bad it is. What am I looking for when it's out? Oiled down, burnt? I have been noticing in past weeks as well as from friends at the track that it smokes making WOT passes. They never say WHAT color, but I've noticed black and white smoke separately when on the throttle. Not billowing, just slight

[acannell]

I'll check all the lines running to the MAP once I'm off work. If it's bad, how much for another 3bar? I really am not fond of pulling the o2 sensor as it's a pain to get to, but I will pull it to see how bad it is. What am I looking for when it's out? Oiled down, burnt? I have been noticing in past weeks as well as from friends at the track that it smokes making WOT passes. They never say WHAT color, but I've noticed black and white smoke separately when on the throttle. Not billowing, just slight

STOP.

Do not remove the O2 sensor.

Test the O2 sensor for function using your multimeter.

Measure its output voltage with the multimeter.

Observe it at idle after the car warms up.

The voltage should swing several volts back and forth about once or twice a second.

My question for you, which is directly relevant to the idea your O2 sensor feedback is somehow involved in this problem is:

What O2 sensor is connected to your ECU, the options are:

A) Your stock O2 sensor

OR

B) The narrowband "simulated" O2 sensor of your wideband

ALSO. What is your AFR at idle after the car has warmed up?

[BoostedDrummer]

I just got off work and got home. Got to meet the Secretary of the Air Force today! Anyways, of the 2 options, probably the narrow band option you listed. I'm not exactly sure of which, so that's why I was going to do a video of what it's set up as to give everyone a visual. From what I recall, my idle is usually around 14-15 when it's warm. Right now it won't even warm up since it likes to die after start up. I'll give it a go when I had out there to take the video

[minigts]

Keep in mind, the narrow band O2 will only put out 0-1 volt, so be sure to use the meter based on that. Don't expect voltage to be all over the place. It will be from 0-1v, so measure accordingly.

With regards to the baro sensor, did you bypass it physically and by disconnecting it or via a tune? The only way to bypass it and sorta take it out of the equation is by disabling it in the tune and setting a default value. The good, you can get rid of it and take potential future problems out of the equation. The bad, if you change elevation a lot, your car won't know and you could run rich or lean depending on the the air density. I'm pretty sure that's how it is used.

[acannell]

Keep in mind, the narrow band O2 will only put out 0-1 volt, so be sure to use the meter based on that. Don't expect voltage to be all over the place. It will be from 0-1v, so measure accordingly.

With regards to the baro sensor, did you bypass it physically and by disconnecting it or via a tune? The only way to bypass it and sorta take it out of the equation is by disabling it in the tune and setting a default value. The good, you can get rid of it and take potential future problems out of the equation. The bad, if you change elevation a lot, your car won't know and you could run rich or lean depending on the the air density. I'm pretty sure that's how it is used.

yeah thats right I was thinking of my jeep which actually does swing a few volts

[BoostedDrummer]

Haven't had a chance to really look at the car for the past two days since I've been hanging out with my parents. But we took a glance at it today and my dad decided to look at the MAP sensor a little closer. So it was taken apart and it smelled like burnt electronics..

[BoostedDrummer]

Posting this from NAJ at turbododge related to code 13 diagnostics.

Fault Code 13/14...
No Change In Map Voltage From Key On To Engine Start or...
Map Voltage Does Not Equal Throttle Position.
Map Voltage Low
Map Voltage High

Map Wiring 85/86/87 SC Logic Module Mounted
BK Wire, Signal Return
WT
RD

Map Wiring 87 -94
VT/WT Wire, 5 Volt Reference
DG/RD, Map Signal
BK/LB, Signal Return

1)Verify Engine Vacuum from Manifold to Baro Solenoid and from Baro Solenoid to Map Sensor.

• Engine Vacuum needs to be 16" - 20" HG.

2)Verify 5 Volt Reference and Signal Return Line.

• Key On/Engine Off
• With Map Sensor Connector disconnected backprobe the 5 Volt Reference Line and Signal Return with a Digital Voltmeter.
• Voltage should read approx. 5.00 volts.

3)Checking Map Output Voltage KeyOnEngineOff.

• Backprobe the Map Signal Line and Signal Return Line with a Digital Voltmeter.
• With the Map Connector plugged in and the Key On/Engine Off read Map Output Voltage.
• You are now reading Barometric Pressure, Voltage should be approx. 2.40 Volts

4)Checking Map Output Voltage with KeyOnEngineRunning.

• With your Voltmeter Connected as in Step 3 and a Vacuum Gauge tee'd between the Baro Solenoid and Map Sensor start the car.
• Compare Map Voltage to Vacuum/Pressure.

5)Quickly snap throttle open.

• Vacuum should drop to 0 and then back to manifold vacuum(16-20" HG).
• If it does not repair restriction in Map vacuum supply line.

I didnt have a vacuum guage but i did have an old 30/20 boost guage. I tested the vac source from Manifold to Baro Solenoid and from Baro Solenoid to Map Sensor. It was pulling 17-18hg on the guage. Next step I disconnected the MAP sensor connector and verified that I have approx 5 volts from the signal line and reference line with a reading of around 4.87 on my multimeter. After that, I plugged the connector back into the MAP and stuck the probes of the multimeter through the back of the connector and turned the key on/engine off. I was supposed to get 2.40 volts and ended up getting 1.59 volts. On the above quote where its underlined and the letters are red is where i think the problem lays. On step 4, it says to check MAP output, but I dont have extra vac line or a vacuum tee, so I just checked the map voltage instead without the vacuum guage. I ended up getting a reading of 0.22volts after i had tried starting the car again and plugging the multimeter back into the plug(this was with the engine off/key off. With the key on and the engine off, the reading went down to 0.05volts. Upon starting the engine, the MAP output would read from 0.02volts to 0.60 colts. I will be loading video of the process in a second. What do you guys think?

[BoostedDrummer]