Galler

Yes, Fuel filter is next on my list, if I cant get my issues cleared up with down stream 02's

Will also be putting in new air filter this weekend as well.

Fuel filter will be next on the list. If this doesnt get cleared up, will probably get a fuel pressure gauge as well and check that.


Anyone have any suggestions for, my low voltage codes?

SoDiezl350

Replacing downstream O2 sensors won't do anything as they don't affect performance.

At WOT, the upstreams don't really do anything either.

Instead of throwing money at random possible root causes, I would run to Harbor Freight and pick up one of their fancy OBD readers. This will let you read a lot of useful parameters such as o2 voltage, MAF airflow, and fuel flow as well.

Just my 2 cents

SoDiezl350

As far as the low voltage is concerned, what kind of o2 sensors did you buy? Were they the kind that need to be spliced in?

Galler

I thought OBD readers only showed codes? Not parameters as you mentioned. And no the 02 sensors I got are Bosch replacements, plug and play.


On a side note, another code popped up on the way home. P0131. Bank 1 sensor 1 low voltage.

SoDiezl350

Some of the higher end readers can log quite a bit of data.

If you have brand new sensors and are getting low voltage it means you're probably running lean. Since the likelihood that both sides have the same issue is really low, this can eliminate things like wiring, catalytic converters, spark plugs, fuel injectors, and so on.

What it leaves is air meter and fuel supply. With the scanner I recommended you should be able to read MAF flow as well as fuel pressure.

Often times your can test the MAF by unplugging it. I would say this is more likely the cause than a fuel filter our pump but it can be both. You may also have a vacuum leak somewhere.

Galler

So I just wanted to update this for some additional info and in case anyone else is still experiencing this.

After replacing both upstream o2 sensors, the car initially was still throwing the low voltage o2 sensors for bank 2 sensors 1&2 and at one point through a code for bank 1 sensor 1. Without doing anything else the codes are no longer getting thrown. (Note: I live in Minnesota and our temperature has dropped 10-15 degrees over the last week or so. Today's temp last I looked was 48 degrees. Which is down from mid 70's where I was experiencing the acceleration issues.)

I am curious if this would correlate to a bad intake air temp sensor? Registering the wrong temps and now with the cooler air everything seems to be functioning?

Again at this point I have cleared all codes and none have returned over the past 3 days. Car does seen to be running strong.

Black 02

When you replaced the sensors did you pull the battery and leave it disconnected for 10-30 minutes to reset the fuel trims?

Galler

I did not unhook the battery at the time of the install, the following day I had taken it off, unhooked the sensors, plugged them back in and waited 20 or so minutes to rebook the battery

rhyno

bad IAT would cause it to flood as car would think its well below ambient outside. good place to check.

Galler

Update. Been busy have not had time to check IAT.

I Will be hooking it up to a couple scanners this weekend one is a Modis 2500. The other I'm not sure, I was told to call some guy with a 15K dollar scanner that runs his own shop.

What metrics should I be looking for when we do that? Fuel air trims ? I really have no idea what to look for. So some direction would be appreciated

SoDiezl350

Mass air flow is the most valuable.

Galler

So before my problem started I had pulled the intake manifold off, including removing the injectors from the manifold, could a pinched or messed up O ring on an injector/multiple be giving me these issues?

roadbike56

#1 question during a manufacturing trouble shooting session is, What changes were made? Next is, When were these changes made? From what you've said, the correlation between the problem and the removal of the intake manifold does not seem coincidental, especially since the cause may be related to a vacuum leak. Let others comment, but I'd look at the most recent change as a possible cause.

Galler

I completely agree. That's why I am basically starting over with this.

The only two things changed were the oil sender unit. And the intake manifold gaskets.

Galler

I think I finally found the issue. I pulled out the injectors out of the manifold and found that one of the injectors had a crack on the tip of it.

I purchased a new injector and will be installing in the next few days.

Is there anything I need to know about swapping an injector? I believe I need to relieve the pressue in the fuel rails? Is there anything else I need to know?

Galler

Update.

After installing the new injector I managed to get a significant improvement on acceleration back.

However. I noticed more than one of the injector ends has cracks In the plastic by the actual nozzle. (The one I replaced was actually chipped.) Needless to say somewhere somehow I messed something up that cracked them. I will need to replace.

I found a deal on 60# injectors for a good price. Although I do not have the mods to really need these injectors, is it acceptable to run them without losing any horse power? They would need to be tuned obviously so I assume they could be adjusted to function with stock air fuel ratio. Am I correct?