Hey guys, I have been having some issues with my truck under acceleration for a while now and need some help diagnosing it. My sig is current, and I have just replaced batteries, cleaned connections and coated with oil today. Before the battery swap I was having VERY noticeable surging under acceleration when cold, and it even started doing it while the motor was operating temps. I also had my interior and exterior lights flickering slightly while driving and was getting a CCD reading from the overhead off and on while driving. I drove it several times today after the batteries and I have no more flickering lights or CCD light so far. The choppy acceleration has gone away for the most part, however, it is still there sometimes even when I've been driving at operating temps for a while. Seems to mainly happen in 2nd and 5th gear the most noticeable, but also in 6th while lightly accelerating sometimes. Should I try resetting the APPS? Could the small fuel leak at the back the head be causing a lack of fuel at certain times? I would think since it's the return line, it would not affect the actual injection? Any ideas?

LOL @ 'upgrade'. Well, it sorta is .

Hey guys I was doing some thinking and had an idea to buy me some time on ordering a TIMBO. Would it be harmful to just simply make it a habit to do a quick reset on the APPS after each drive? I am thinking just turn the truck off after I get to where I'm going, turn the key back on, slowly depress the pedal, key off and get out. Then I come back and when I start it back up it will be reset and I won't have to keep dealing with the jerky throttle. Just long enough to buy me some time to store my nuts for the winter lol. I have a feeling I will be collecting unemployment for a while when it gets really cold out, so I don't want to be spending TOO much money if I don't have to quite yet. I was just wondering if it would be bad or just stupid to keep doing that?

Personally I think it would become a PITA do all the time.

Yes it will be a small pain but I will only do it until around the holidays, maybe as soon as turkey day. The jerky throttle is just becoming very annoying to me, so I just wanted to make sure it wouldn't hurt anything to repeatedly reset it like that. And realistically I will actually only need to do it every few drives or so when it starts to jerk again.

Just keep in mind that if it truly is the apps it could go completely out at any time on you with nowarning. For example, when mine went it first started acting up over 350 miles from home in between nowhere and some place it tripped the cel so once i got pulled off out of the way and figured out what was going on i reset it and luckily continued on home with zero issues. Went out the following morning to unhook the trailer and go fuel up and went to pull out and the truck fell flat on its face. Tried resetting again and did not help. It was bad too i couldnt even get up to speed. So be careful about going far from home or pulling out in traffic until you get it resolved

Personally I think it would become a PITA do all the time.

Agreed

Just keep in mind that if it truly is the apps it could go completely out at any time on you with nowarning. For example, when mine went it first started acting up over 350 miles from home in between nowhere and some place it tripped the cel so once i got pulled off out of the way and figured out what was going on i reset it and luckily continued on home with zero issues. Went out the following morning to unhook the trailer and go fuel up and went to pull out and the truck fell flat on its face. Tried resetting again and did not help. It was bad too i couldnt even get up to speed. So be careful about going far from home or pulling out in traffic until you get it resolved

I hadn't thought of that really. I thought maybe if it got worse I would start experience some dead pedal here and there. Thanks for sharing that, I typically am within a few miles of my house, but even still, it's always a pain to have to get towed or stranded somewhere.

Consider this picture...

[*]No cell service

[*]-25*F outside

[*]Home is at least 20 miles from here

Bad APPS sensor... Not good.

I don't see myself venturing out anywhere like that in the near future... definitely not with any failing parts on my truck. I sometimes wish I lived in a location like that though. But I've decided to take a chunk of next weeks paycheck and get the TIMBO before something does happen though, even if it's only a couple miles away from home. I will revive this thread with the results after I get it installed.

Timbo APPS should be here in a couple days. I set my Edge juice to read the APPS as well and noticed that at idle, it jumps up and down from 0-1%. Also, while accelerating, percentage does not increase smoothly while I experience the choppyness. So that part of the issue should be solved in a few days...Discovered my fuel leak as well. Seems to be slowly squeezing out of the #4 and possibly #5 injectors, not the return T line or the banjo-bolt (which is good news) I tightened them however ever it still seeps out. What typically causes this? Bad o-rings... or should I just loosen and reset them to see if that helps? Oh man, I can see it now... I'm going to have end up replacing something cheap, but then somehow convince myself to just buy the RV275's that I've been wanting so I don't have to pull it apart twice......:banghead:

I set my Edge juice to read the APPS as well and noticed that at idle, it jumps up and down from 0-1%.

Mine does the bounce to on the APPS signal I normally disregard that.

Also, while accelerating, percentage does not increase smoothly while I experience the choppyness.

APPS sensor might still play a roll in the in choppyness problem.

Timbo APPS should be here in a couple days.

Discovered my fuel leak as well. Seems to be slowly squeezing out of the #4 and possibly #5 injectors

Time for a set of crossover o-rings...

Oh man, I can see it now... I'm going to have end up replacing something cheap, but then somehow convince myself to just buy the RV275's that I've been wanting so I don't have to pull it apart twice...

Hell that far you might as well...

Timbo got here yesterday, I might get around to it tomorrow, along with my steering bushing upgrade.These crossover o-rings... do they come with a set of new RV275's or is it a seperate purchase? I will look at prices for both but I have a gut feeling that my wallet is going to be a little slimmer pretty soon...Just checked out DAP and they have a couple different options for the 275's. There was an un-named RV275 for $250, then two genuine Bosch options at $390 and $405. I'm not sure what the differences are, but I'm assuming I will want to go with a genuine part?

I would go with the Bosch. I bought mine from DAP. I dot remember 2 choices though. The crossover orings are a seperate item, but are not expensive. DAP should be able to help you with that also.

Two thumbs up to Timbo for not only solving my issue, but taking my truck to a level of responsiveness and smoothness that I have never known... Install was fairly simple but I did manage to drop and lose a couple screws and a torx bit. Had to use a propane torch on the set screw after ruining another t-20 torx trying to adjust it. But after it is all said and done my problem is fixed so I am happy.

That just leaves the fuel leak yet. I think I am going to try some of this sealant tape I picked up from Ace a while back. It's like a teflon tape but thicker and I believe it withstands fuel and high heat, I wish I saved the package so I could read the specs again. I'll just seal up the threads and see if that works. I just need a temporary leak stop so I am not continuing to leave stains where I park.

- - - Updated - - -

Found it, check this stuff out. If it actually works, it pretty cool stuff. Will withstand fuels, and temps of like 500. I actually used this stuff to make my snubber setup for the fuel pressure gauge.

http://www.rescuetape.com/?gclid=CLLEzb-z47MCFQ-e4Aod3G8Axw

Good deal! It always feels good getting your rig figured out, esp doing the work yourself. You save yourself some cha ching and sometimes even learn something in the process.

Good deal! It always feels good getting your rig figured out, esp doing the work yourself. You save yourself some cha ching and sometimes even learn something in the process.

It does feel great. I'm finding that I actually have to "re-learn" the feel of my throttle and clutch now, because it is just so much more responsive than it ever has been. I've been over-revving quite a bit lately lol.

Just checked out DAP and they have a couple different options for the 275's. There was an un-named RV275 for $250, then two genuine Bosch options at $390 and $405. I'm not sure what the differences are, but I'm assuming I will want to go with a genuine part?

difference is shipping to canada, same part just export tarrif.

TH Racing is a Canadian vendor for the site and he should be able to do you some better prices.

TH Racing is a Canadian vendor for the site and he should be able to do you some better prices.

I will check that out if I decide to do the injectors, thanks.