Running rich and don’t know why.

[Sailing Santa]

Let me start off with the background.
1997 Ram 1500 4x4 Laramie.

-Swapped in remanufactured 5.2 with a RV cam for more lowers torque.
-New Edlebrock intake
-New throttle body
-New injectors and billet rails
-New temp sender
-New o2 sensors
-New MAP
-IAC was cleaned and reinstalled
-New TPS
-3” long tube headers - all the way back.
-Fuel sync has been set and confirmed.
-Timing has been set and confirmed.
-*NO* vacuum leaks.

After start, while in open loop, runs but rich ... as it’s supposed to do.

When it goes into closed loop, the idle goes bad and will stall at the most inconvenient times... like in the middle of the intersection. I’ve unplugged the upper o2 sensor (with some wire cutters) to force it to stay in open loop.

Now with all these new parts, where does one start looking? Has anyone heard of a computer or harness going “Tango Uniform”?

Tidbit of information. The OLD engine ran rich too. Kinda makes a guy wonder.

Dave
Merritt Island FL

 

[Fast69Mopar]

There are several things that can cause the engine to run rich. First, we need the Upstream O2 sensor plugged in and working. Without it the PCM will default to a predetermined table to control the AFR in open loop operation and it will be rich by default.

Next, I would get a quality scan tool connected to this truck. A look at the adaptive memory would help so we could see if the O2 is switching or if it's stuck. The Short Term Fuel Trim and the Long Term Fuel Trim should reflect the rich condition but we could see if the long term is maxed out at -25.0 and trying to pull fuel out.

Do you have a scan tool that you can use?

 

[Sailing Santa]

>Without [the upstream o2] the PCM will default to a predetermined table to control the AFR in open loop operation and it will be rich by default.

Yeah, that was kind of the point, to force it in open loop because when it switches to closed loop the idle pulses playing havoc with the IAC and within a minute or two it will stall.

>Next, I would get a quality scan tool connected to this truck. A look at the adaptive memory would help so we could see if the O2 is switching or if it's stuck.

I don’t personally have one but could take the truck back to a shop that does. I’m not altogether convinced they know what they’re looking for/at. I remember them saying that they could see the upstream heater was on.

>The Short Term Fuel Trim and the Long Term Fuel Trim should reflect the rich condition but we could see if the long term is maxed out at -25.0 and trying to pull fuel out.

You say “stuck” like it’s a mechanical issue. Is there a place or signpost in the software I could guide the mechanics to and once there, is there an adjustment? What should I see there? Once there, is it possible to un-max it?

Is there something else that could be in play here? Are all the performance issues hinged on this setting?

 

[dapepper9]

Did you get tuning with all this work?

 

[Yeret]

What did you go with for a throttle body? Are the injectors new OEM, or are they something else?

Also, even if the engine was running right, you're not going to gain nearly as much power as you think without some proper tuning. You strike me as an old-schooler, which is totally cool. But tweaking the timing and fueling of a modified fuel injected engine isn't as simple as turning the cap and swapping the jets (if only, LOL). You're gonna need to hook up with a good tuner to get everything running as it should.

 

[Fast69Mopar]

Two things I forgot to ask about in my earlier post. You said the original motor was running rich, right? Did you do anything to try to correct the rich condition on the original motor?

Also, I forgot to ask about tuning. Did you work with a tuner to dial in the tune once the new motor was in the truck?

Like @Yeret posted, what injectors to you install with the new billet rails? Did you reuse the original injectors or go with an aftermarket injector?

 

[Sailing Santa]

The intake is from Hughes. The throttle body is the “big gulp” from Hughes and the billet fuel rails are... Hughes. The cold air intake and riser are Airaid. The injectors are new Bosch and are what was recommended by Mopar (and Hughes). I did have a tuner programmed as recommended by Hughes. (I expect to get a Christmas card from Hughes now )
Currently it’s in its Street configuration versus Towing. I had to fill out a form with info on everything from cam loves to tire size. The tuner they sent did ease up the starting. There’s nothing I can personally see/do for adjustment on the fly. It’s not a chip but plugs up to the obd2 for uploading. Once done, it lives under the seat in a ziplock.

I replaced just about everything on this project save the valve covers. There’s a radiator, a New distributor, new In-tank pump, etc etc etc.

I tried many things to get the old engine to behave but when I got to the point where I found two cylinders with less than 30 pounds of pressure, I wrote off the engine. Later I found that I had cracked heads on both sides. I had hoped that this new engine would have fixed the running rich. It didn’t. I’ve thrown more cash at this old truck than is sensible but I’m to the point I don’t wanna admit defeat. Still... cheaper than a car payment.

You are most correct, I’m more of an old timer. I’ll work on my old Lehman boat diesel by Braille, get good results and still be smiling. I do understand that twisting the distributor here messes with fuel sync versus timing. I’m learning more than I care to about fuel injected 318s.

Where I am now...
I still have to go get it back on a scanner. Even though, if I find that the fuel sync numbers are different between open and closed - if it IS stuck and pushing more fuel than necessary, how do I un-stuck it? What numbers am I supposed to see? I suppose I could replace the MAP again. It’s possible it’s been bad right out of the box. As far as I can figure, everything sensor wise for the mixture has been replaced at •least• once.

 

[Fast69Mopar]

If the old motor was running rich do you have an diagnostic data from it? What did the adaptive a look like?

Now, with the new setup, did you tell Hughes about the rich condition when you filled out the spec sheet? The tune they built may very well have made the situation worse.

Did you do any data logging to send to Hughes so they could see how the current setup is running? Are you using the SCT X4 for tuning?

Have you connected a mechanical vacuum gauge to the engine to see what it's pulling at idle?

 

[dapepper9]

Hughes tuning is done by a different shop called Performance Injection Equipment. They're notorious for being rich and stumbly.

Beimg that you had issues with the old motor it could be a multitude of things. Bad 02 sensors and bad replacements are known to happen, bad map sensor, incorrect injectors, etc. The bad motor only having 30psi of compression could've contributed as well.

 

[dapepper9]

Also the poor idling could be several things as well that isn't actually based on a rich condition. The rich condition may just be a side effect.

Things affecting the idle and stumbling could be in the tune, Idle Air Control Valve, Throttle Position Sensor, Manifold Air Pressure sensor.

Any of those sensors you replaced, if you have the old ones that you can ***** back in would be a good way to test them. They can also be tested with a multimeter but i can't remember the procedure off the top of my head right now

 

[smokey1757]

It could be that the big gulp is too much for the 318. I read that somewhere

 

[dapepper9]

It could be that the big gulp is too much for the 318. I read that somewhere

Its not. Throttle bodies don't really get "too big" unlike carbs. "Too big" a throttle body just isn't as calm off idle. For cable driven systems anyways.

For drive by wire, too big is a thing when it comes to getting it to idle and drive smooth at low throttle

 

[jo3gee]

Check the voltages on the tps. Particularly the ground and 5v (pin 1 and 3). Also, there is a chance you may have the ground and 5v reversed for the particular tps sensor installed.

 

[Sailing Santa]

Just ordered an OBD2 scanner last night. Web research on my choice has very good, professional level reviews. The software end is called TouchScan and I added the Professional add-on license *and* got the iOS app for quickie observations. (www.OBDSoftware.net) The reader I opted for is the OBDLinx MX+. I’m excited to be finally able to peer into the computer mysteries that have been currently kicking my butt. Surely there will be people here to tell me how and why I’ve wasted my money. All I can point out is, it’s leagues beyond what I have currently.

 

[Sailing Santa]

Check the voltages on the tps. Particularly the ground and 5v (pin 1 and 3). Also, there is a chance you may have the ground and 5v reversed for the particular tps sensor installed.

How would that happen when the connection only goes on in one orientation?

There *is* a modification to the tps available that I have not done.

http://www.hughesengines.com/Upload/productInstructions/ThrottleBodyInstructionSheet2011.pdf

 

[dapepper9]

How would that happen when the connection only goes on in one orientation?

There *is* a modification to the tps available that I have not done.

http://www.hughesengines.com/Upload/productInstructions/ThrottleBodyInstructionSheet2011.pdf

The wires aren't going to be swapped but don't modify the tps. That will just make problems worse. That modification to adjust it is only making the throttle seem more open than it really is. On a 94 or 95, i could see doing it. Not here

Here's the testing procedure:
https://troubleshootmyvehicle.com/chrysler/5.2L-5.9L/how-to-test-the-tps-sensor-1

 

[jo3gee]

How would that happen when the connection only goes on in one orientation?

It shouldn’t, but I had that problem when i swapped my jeep tps with the dodge (custom build). This shouldn’t be your problem.

But, still check that you are getting 5v and a good ground. If not, the pcm will default to open, like the tps is not even connected.

 

[Sailing Santa]

~Update~
The engine scanner arrived and as suspected, the long and short term fuel trim are way out of spec.
Short term is at -15.62%
Long term is at -29.69%

Map is 29.83 inHg
Coolant = 176.9•
Intake air temp 134.6•

So once again, I’m at my knowledge limits. What do I do about fixing it?

 

[dapepper9]

Get with another tuner and get them a datalog. My bet the current issue is tune related

 

[Fast69Mopar]

~Update~
The engine scanner arrived and as suspected, the long and short term fuel trim are way out of spec.
Short term is at -15.62%
Long term is at -29.69%

Map is 29.83 inHg
Coolant = 176.9•
Intake air temp 134.6•

So once again, I’m at my knowledge limits. What do I do about fixing it?

I don't remember if you said this before or not but were you running a canned tune or a custom tune with the old motor?

If you don't have any vacuum leaks allowing unmetered air into the engine and your mechanical cam timing is correct I am in agreement with @dapepper9's thinking that this is tune related.

Your MAP Baro looks normal. How much vacuum is the motor making?

Does your new scan tool have data logging capabilities? If so, I would get in touch with a reputable tuner and ask them to take a look at your data log