Throttle Hestitation Surge Arrow PCM

[cubeman]

Hey folks, recently had a new issue pop up after 8-9k miles of driving on Arrow PCM. It doesn't happen while driving all the time, Picked car up from Tators after a new clutch/flywheel/slave and everything was dandy. We figured the clutch was already worn and was the source of this issue but it still exists. I drove 50 miles home and a few miles before the house the issue reappeared.

When rolling into the throttle the car is hesitating or sluggish, like I'm in 6th gear going 10mph (when i'm really in 1st). Suddenly half way through the throttle the car wakes up and goes. Once this happens the car is fine on and off the throttle, until you get off throttle for a while it returns. When this happens the backfires/decel pops turn into gun shots, like the car is dumping way more fuel then usual. I don't have this problem when not in gear.

I saw another post but the user had quite the bit modded, I'm currently looking into maybe a throttle relearn or MAF sensors / throttle body replacement. Just wondering if anyone has seen this issue. Next week I'm switching to HPTuners regardless so I can also log and view data.

[99RT10]

I think Arrow had a few updates to their tune. Not sure how long ago you did it, but I would send it back to get re-flashed

[cubeman]

I think Arrow had a few updates to their tune. Not sure how long ago you did it, but I would send it back to get re-flashed

I'd consider that if I wasn't getting off Arrow so I can use nitrous. Also annoying I can't just plug in a laptop and log this PCM and figure out if the car is running lean or something isn't working correctly.

[SRT_BluByU]

Could be a clogged injector...

[Jack B]

If you are getting ready to run nitrous this might be a good time to add a wideband, they are inexpensive and not that hard to install. To go a step further most dash mounted OBD scanners allow two analogs in. With the combination of the wideband and the OBD input you can log the majority of the engine PIDS.

Your current issue could be a variety of things. It does sound like fuel or cam/crank sensor, however, the pcm could manifest itself in a similar way. It probably is not a single plug or injector, these cars are can run on nine cylinders and not totally fall on theiroem face. I would wager a good scan tool will show the problem or at least show the history. The oem dash display only shows a limited range of codes, typically only those associated with environmental problems.



I'd consider that if I wasn't getting off Arrow so I can use nitrous. Also annoying I can't just plug in a laptop and log this PCM and figure out if the car is running lean or something isn't working correctly.

[cubeman]

Could be a clogged injector...

This case I may consider swapping injectors and plugs just to eliminate them all as a problem.

- - - Updated - - -


If you are getting ready to run nitrous this might be a good time to add a wideband, inexpensive and not that hard. To go a step further most dash mounted OBD scanners allow two analogs in. This will allow you to monitor the majority of the engine PIDS.

Your current issue could be a variety of things. It does sound like fuel or cam shaft sensor, however, the pcm could manifest itself in a similar way. It probably is not a single plug or injector, these cars are can run on nine cylinders and not totally fall on there face. I would wager a good scan tool will show the problem or at least show the history. The dash display only shows a limited range of codes, typically only those associated with environmental problems.

Wideband is being added along with the nitrious install

[cubeman]

Just an update, Dropping it off at the dealer Tuesday. Going to try a throttle relearn first, then look into injectors and plugs.

[cubeman]

Took it for a quick drive to try and replicate it. Drove around 3 miles no issues, sat in drive through and i noticed some quiet "pops" happening in the exhaust without any throttle input. Once i put it in gear the car stumbled on itself and no throttle input till 50%. Quickly parked it and sat for 2 minutes. Started it back up and car resumed normally. A couple of miles later it resumed the same issue.

At-least I know it's able to be replicated. A little upset that a certain shop that did my clutch didn't notice this issue after I dropped it off specifically because of this..

[ViperGeorge]

Bad/clogged Cat maybe? Clogged fuel filter from a tank of bad gas?

[Jack B]

This case I may consider swapping injectors and plugs just to eliminate them all as a problem.

- - - Updated - - -



Wideband is being added along with the nitrious install

Innovate LM series has analog out, the signal can go into a dash logger. What you see on an AF gauge is nothing like what the logger will show.to

[cubeman]

Bad/clogged Cat maybe? Clogged fuel filter from a tank of bad gas?

Looking at this and one other thing now. In colder weather I was throwing a code for the RPM not being stable enough which could have been the beginning signs of this issue now. The right exhaust is the one that shoots gun shots when the car is lugging. Might be the right throttle body acting up. Dealer Tuesday hopefully get this resolved.

Yesterday the car barely exhibited this issue but we kept it in going fast (80mph+) the whole trip. Today it's nothing but a problem in the lower speeds. If i rev the car up to 3-4k (50%+ throttle) before engaging clutch / gear the problem goes away for a bit.

[Steve M]

Innovate LM series has analog out, the signal can go into a dash logger. What you see on an AF gauge is nothing like what the logger will show.to

I'd highly recommend looking for a wideband that you can log digitally - analog out stuff is alright, but I've always had issues with ground offsets that can make accurate logging a nightmare. AEM is making some nice offerings that offer this feature.

[Jack B]

I'd highly recommend looking for a wideband that you can log digitally - analog out stuff is alright, but I've always had issues with ground offsets that can make accurate logging a nightmare. AEM is making some nice offerings that offer this feature.

you can use the LM series in its digital native mode if you want. My suggestion allows you to take the analog signal into a modestly priced obd scanner/logger. This way you can also easily log, throttle, IAT, rpm, timing, mph and the analog AF. Whether it is digital or analog does not matter much for AF, the simple rate is low.

Just logging AF without the above pids does not tell you much. I forgot to add, you will want to log both pedal and throttle.

[Steve M]

you can use the LM series in its digital native mode if you want. My suggestion allows you to take the analog signal into a modestly priced obd scanner/logger. This way you can also easily log, throttle, IAT, rpm, timing, mph and the analog AF. Whether it is digital or analog does not matter much for AF, the simple rate is low.

The ground offset issue with the analog output is a very real thing though - if you don't account for it, there will be a difference between the digital output and what your data logger is reading from the analog input. I spent more than a few hours chasing my tail with my old Camaro that I tuned with an LC-1 through HPTuners due to this issue. This time around, I did a little more poking around and saw that there is now a way for certain AEM units to spit the digital data out on the vehicle's CAN bus as a unique PID - HPTuners can grab that PID off the bus and merge it with the other data you are logging. No ground offset issues, and it supports a 100 Hz logging rate, which is pretty good for tuning a vehicle.

Just another option - one which I think is a much better solution than what Innovate has offered in the past. It looks like their new LC-3 might support this functionality though, and I think you'll see more products going this way in the future.

As for the OP, your car definitely has something going on that needs sorted before you start shooting giggle-gas into it. I'd guess plug wires, a clogged cat, or a cooked sensor wire or two.

[slowhatch]

Sounds exactly like what i experienced when i was killing coils due to shitty plug wires.

Changed all the plugs, put on AB wires, and car ran like silk.

[Arizona Vipers]

First thing you should do is the throttle relearn. This fixed a similar issue for me. It's the cheapest and easiest thing to try first.

[SRT_BluByU]

any update?

[cubeman]

Currently at the dealer. The car is currently leaning out in Bank 2 (Passenger side cylinders) which is making the motor dump fuel which explains the gun shots. Due to the Arrow PCM disabling a bunch of codes the dealer doesn't want to go further diagnosing it until a stock PCM is put into the car. A factory PCM will be put into the car hopefully mid next week. CJ (Viper Tech) Is currently going to check for any vacuum leaks to explain the leaning out while waiting for a PCM. One O2 sensor is not responding at all on that side and isn't sure if it's Arrow PCM related or actually a failed O2.

Hopefully next week more answers. I will keep you guys updated.

[cubeman]

O2 Sensors on passenger side were burnt to a crisp even through a bunch of insulation. Burned out the passenger ARH Cat. Replaced and went to stock PCM. Going HPTuners this week. Just did a 1300 mile rally and car did perfect even with ARH Longtubes/exhaust/cats. Going to probably hollow out the driver cat now also and just tune it for emissions.

[Jack B]

O2 Sensors on passenger side were burnt to a crisp even through a bunch of insulation. Burned out the passenger ARH Cat. Replaced and went to stock PCM. Going HPTuners this week. Just did a 1300 mile rally and car did perfect even with ARH Longtubes/exhaust/cats. Going to probably hollow out the driver cat now also and just tune it for emissions.

Was the cat plugged and/or did it burn through

[cubeman]

Was the cat plugged and/or did it burn through

The honeycomb in the ARH Cat had maybe 20% of it's material left when removed. The rest was melted/shot out/or stuck in the ARH Muffler now. CJ did a great job at Meadowlands working most of it out of the muffler but some of it is in the resonators. He also punched out the rest of the cat for me.

It was also stated a short mile drive and the passenger sill hit 360F. The motor just kept dumping fuel as it thought there was a lean condition.

Edit: I'm also mentioning that the front O2 sensor had very little burning at all and wasn't through the wiring. The rear 02 was completely shot and burned to a crisp and had Cat fused to it.

[ViperGeorge]

With the Arrow PCM you do not need to run a rear O2. The PCM doesn't look at them although it still activates the heating circuit. Take out the rears and plug the bung. You can find a suitable threaded plug at Lowes.

[cubeman]

With the Arrow PCM you do not need to run a rear O2. The PCM doesn't look at them although it still activates the heating circuit. Take out the rears and plug the bung. You can find a suitable threaded plug at Lowes.

I no longer have the Arrow PCM. What's weird is once the stock PCM was put in, the front O2 did not throw a voltage code. The rear O2 did. For something that shouldn't be reading the rear O2 it seems like it was depending on it.

[ViperGeorge]

As stated the Arrow PCM does not read the rear O2 sensors. However, there is a pre-heat circuit which IS activated by the Arrow PCM. The pre-heat circuit is a 12 volt line, most other sensors in the car are 5 volts. When this wire melts and shorts the car can throw many, many codes and will not run well. It often will blow one of the ASD fuses which causes the car to barely run.

I've seen cars that have melted the rear O2 wires throw upwards of 25 different codes at the same time. There is so little room it is hard to insulate the wires well enough. This is the main reason I have not put headers on my ACR-E. I had them on my 09 ACR and on my 15 TA 2.0 but they were more trouble than they were worth. Also the reason I've been reluctant to upgrade to the 9 liter - it needs headers.

[SRT BILL]

Rookie question here, is possible to reroute this wire & sensor and place the pick up point in a better position?

[Jack B]

The rear O2 has no control over AF, the front O2/wiring had to be bad. However, the rear O2 can set codes, but, in this case the Arrow pcm would not acknowledge them.



The honeycomb in the ARH Cat had maybe 20% of it's material left when removed. The rest was melted/shot out/or stuck in the ARH Muffler now. CJ did a great job at Meadowlands working most of it out of the muffler but some of it is in the resonators. He also punched out the rest of the cat for me.

It was also stated a short mile drive and the passenger sill hit 360F. The motor just kept dumping fuel as it thought there was a lean condition.

Edit: I'm also mentioning that the front O2 sensor had very little burning at all and wasn't through the wiring. The rear 02 was completely shot and burned to a crisp and had Cat fused to it.

[Jack B]

Rookie question here, is possible to reroute this wire & sensor and place the pick up point in a better position?

Yes, it can be kept out of harm's way.

[ViperGeorge]

The rear O2 has no control over AF, the front O2/wiring had to be bad. However, the rear O2 can set codes, but, in this case the Arrow pcm would not acknowledge them.

True, but if you melt the rear O2 wires and short the heating circuit you will throw many codes and likely blow the ASD fuse(s). When this happens the car will run like crap or not at all even though the PCM isn't looking at the rear O2.

[Jack B]

True, but if you melt the rear O2 wires and short the heating circuit you will throw many codes and likely blow the ASD fuse(s). When this happens the car will run like crap or not at all even though the PCM isn't looking at the rear O2.

That is why you totally remove the rear O2 assembly, of course you need HPT or Arrow

[ViperGeorge]

That is why you totally remove the rear O2 assembly, of course you need HPT or Arrow

Agreed, that is exactly what I did.

[blingnoring]

As stated the Arrow PCM does not read the rear O2 sensors. However, there is a pre-heat circuit which IS activated by the Arrow PCM. The pre-heat circuit is a 12 volt line, most other sensors in the car are 5 volts. When this wire melts and shorts the car can throw many, many codes and will not run well. It often will blow one of the ASD fuses which causes the car to barely run.

I've seen cars that have melted the rear O2 wires throw upwards of 25 different codes at the same time. There is so little room it is hard to insulate the wires well enough. This is the main reason I have not put headers on my ACR-E. I had them on my 09 ACR and on my 15 TA 2.0 but they were more trouble than they were worth. Also the reason I've been reluctant to upgrade to the 9 liter - it needs headers.

what if you do a heads and cam, can you still keep your stock headers and upgrade the rest of the exhaust?

[Jack B]

what if you do a heads and cam, can you still keep your stock headers and upgrade the rest of the exhaust?

Makes no sense, you will leave too much hp on the table.

[ViperGeorge]

what if you do a heads and cam, can you still keep your stock headers and upgrade the rest of the exhaust?

The very existence of this thread is the reason I have been reluctant to add anything requiring headers to my ACR-E. My 09 ACR had ARH headers and I burnt the rear O2 wires a few times despite insulating the hell out of them When I went to the Mopar controller I removed them. On my 15 TA 2.0 I had Bellangers and melted the wire harness and PDC (the rear O2s were removed right away). I insulated the hell out of everything after that but still the insulation on the front O2 wires would get crispy.

[cubeman]

The very existence of this thread is the reason I have been reluctant to add anything requiring headers to my ACR-E. My 09 ACR had ARH headers and I burnt the rear O2 wires a few times despite insulating the hell out of them When I went to the Mopar controller I removed them. On my 15 TA 2.0 I had Bellangers and melted the wire harness and PDC (the rear O2s were removed right away). I insulated the hell out of everything after that but still the insulation on the front O2 wires would get crispy.

Going to take a look at the passenger wires after a little over 1k miles of driving with the new insulation. I may consider removing the rear 02's as next week I'm punching out the ARH Cat on the driver side. No point of undoing the wrap on that side. Rather just punch out the material and wrap the driver as well. Reduced sill temps is a bonus.

[Jack B]

Going to take a look at the passenger wires after a little over 1k miles of driving with the new insulation. I may consider removing the rear 02's as next week I'm punching out the ARH Cat on the driver side. No point of undoing the wrap on that side. Rather just punch out the material and wrap the driver as well. Reduced sill temps is a bonus.

The cat delete pipe may be a better option. In general, changing diameters can have dramatic differences on fluid flow. In this case you would go from small, to large, to small. If you have already dyno'ed, it might be a good idea to dyno again. I can tell you this, in my case, the ARH system dramatically reduced temps over the Belanger's. I went with 3" all the way out.

[parabs]

...I can tell you this, in my case, the ARH system dramatically reduced temps over the Belanger's....

Very interesting, dramatically reduced temps where exactly? Are you speaking of your belangers getting necked down to 2.5”?

[cashcorn]

Is it possible to go 3" from the stock exhaust manifold, to 3"hi flow and then 3" muffler? thanks

[cubeman]

The cat delete pipe may be a better option. In general, changing diameters can have dramatic differences on fluid flow. In this case you would go from small, to large, to small. If you have already dyno'ed, it might be a good idea to dyno again. I can tell you this, in my case, the ARH system dramatically reduced temps over the Belanger's. I went with 3" all the way out.

Right now it's ARH Headers, Cat's, Exhaust. Aren't they all the same diameter?

[Jack B]

Right now it's ARH Headers, Cat's, Exhaust. Aren't they all the same diameter?

A large percentage of the both ARH and Belanger's used a 2-1/2" turnout or reducer so it would match the stock muffler. I have a set of 2-1/2 turnout/cat delete pipes that I will sell. ARH wants $500 for a set of cat delete pipes.

[cashcorn]

bump.. Is it possible to go 3" from the stock exhaust manifold, to 3"hi flow and then 3" muffler? thanks

[Jack B]

bump.. Is it possible to go 3" from the stock exhaust manifold, to 3"hi flow and then 3" muffler? thanks

You would need a 2.5 to 3 adapter and the right mix of parts.