68RFE Trans Surging When In Reverse?

[Rmfb99]

I have read a few forums about motor surges when shifting into reverse.

Has anyone figured out the problem?

I did read a forum that DRD posted stating that sometimes that happens with specific years.

I do have the surge or lope, whatever you want to call it; when you fire it up and throw it in reverse right away, then after about 15-20 seconds, it goes away.

Everyone looks, making me look stupid when I’m leaving somewhere.

I have checked the actual and desired rail pressure, which is within 100.

I didn’t have any of this till I got some trans tunes, but then again, I only had the truck two weeks before getting them.

I usually use remote start, and I never have the problem.

Also, line pressure I have noticed is in the 200s occasionally after I hop in the truck after using remote start.

Is that normal, just being cold and starting?

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[Corkey]

How many miles since the tunes?

Was a relearn done with no tow haul, exhaust brake, and no more than 30% throttle done during the 300 to 500 miles that are needed for the procedure?

That will help narrow a few things down.

Also, was a charger hooked up while putting the new tune in?

I'll have to dig on the cold start line pressure.

I believe the stock is 160 170psi off the top of my head, as well, with it also expected to increase the pressure a tad to help engage the clutches better than stock.

I recall Ray mentioning that if you have 3 to 5k miles since the installation, the truck has already learned the habits it's being told to do.

That's if that's your scenario.

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[Rmfb99]

I went about 350 miles with no exhaust break or tow-haul and under 30% throttle the first 200, then the rest under 50.

I have 1400 miles on it so far*.

I did have a charger on when loading the tune, and I didn’t have any problems loading the 1st drive.

I drove backroads for stop and go 1st-6th gear until around 350 miles.

Now, the line pressure problem, I’m unsure if it’s just on start-up or midway through a warm-up.

I will start it manually tomorrow and watch the gauge and see; when I was driving, the highest I saw was 184psi, I believe, but usually not over 170.

It doesn’t affect anything while driving; it feels perfect shifting.

The surge issue is warm or cold, but it’s not every start-up.

The exhaust brake works great, and I use it every day.

New Year’s Eve, I did my trans filters, thermal bypass, and a deep pan, FYI, but this problem was before.

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[Rmfb99]

I did happen to get a photo of the MM3 today before work.

If you read the max, you can see what I’m talking about with line pressure and the same with rail pressure.

191psi was 4th gear when I got on it a little on the highway ramp.

I just started the truck before leaving work, and with the exhaust brake whistling, I can hear it loping, but I’m guessing that’s to do with it being -5 degrees outside.

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[KJC]

Try turning off your exhaust brake and see if it still does it.

I just put a BD Screamer turbo on my '09, and for whatever reason, now, when it's cold and the EB is on, it surges when I put it in gear but goes away once warmed up.

If I turn off the EB, it doesn't surge at all.

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[Lineguy]

I have read a few forums about motor surges when shifting into reverse.

Has anyone figured out the problem?

I did read a forum that DRD posted stating that sometimes that happens with specific years.

I do have the surge or lope, whatever you want to call it; when you fire it up and throw it in reverse right away, then after about 15-20 seconds, it goes away.

Everyone looks, making me look stupid when I’m leaving somewhere.

I have checked the actual and desired rail pressure, which is within 100.

I didn’t have any of this till I got some trans tunes, but then again, I only had the truck two weeks before getting them.

I usually use remote start, and I never have the problem.

Also, line pressure I have noticed is in the 200s occasionally after I hop in the truck after using remote start.

Is that normal, just being cold and starting?

I had the same problem, which disappeared after replacing the injectors.

I thought for sure it was transmission-related, but it eventually got worse and started surging in park, too.

A good injector cleaner would make it better for a short.

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[Scully Motorsport]

I bought my truck with a 170k with this same issue but worse.

Bad in reverse but surges in drive too sometimes. IF I put it in park it goes away.

I actually posted about it on here awhile back.

I was really hoping the tune would magically fix it but it did not.

After posting I was told to replace the fuel pressure actuator and that totally worked for a little while.

I have been dealing with the issue since I got the truck so it is great to hear its not driveline related.

I thought for sure it was a converter issue or something.

Not that the injectors are any cheaper.

I have the rail off right now doing a grid heater delete and monster ram (don't judge, I got it for free from a friend for some work).

I think I am going to put some injector cleaner concentrate right down the injector tubes and in the fuel rail when I put it back together.

Any reason I shouldn't?

I have no other signs of injector issues so I would hate to just replace them for that.

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[Jordan86]

If by surging you mean the truck will go from 650-800 rpm, mine also does this, but only on start-up when holding the brake down hard.

Mine has done this from new.

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[Scully Motorsport]

Yeah, it's just an idle surge around that RPM range.

It's only in gear and usually on the brake; it's always worse in reverse than forward.

Since I put my truck back together, I put injector oil/cleaner right in my fuel rail, and it has been much better, which kind of proves the 'line guys' post.

I noticed it when backing up a trailer, but I will play with the parking brake and see if the brake booster changes anything.

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