SOLVED: One-time hiccup while accelerating

[Andy Chesek]

1999 K2500 pickup EC LB
NV4500
80k miles
4" pinnacle exhaust
TurboMaster (gray spring at 2")


Just recently I've started to get a hiccup around 2400 rpm while accelerating moderately to heavily in my truck. This seems to only happen after I've been horsing around for a while, like racing with other trucks on the highway or hauling butt on the backroads. And I've only noticed this in 4th or 5th gear. For example, I'll upshift from 3rd to 4th and the rpm's will climb to 2400, it'll hiccup for a split second like the fuel is clipping out or something, then it resumes climbing and the truck continues to accelerate.

My truck has done this 5 or 6 times, and it's not something I can reproduce each time I go out driving. It's only happened those few times so far. Any ideas?

Using a recently changed Purolator air filter right now, if that matters. Fuel filter was changed 15k miles ago (time to replace I guess). Thanks.

[ 08-25-2004, 05:15 AM: Message edited by: 93_Burrito ]

[catmandoo]

thats happened to me also on my 94 sub,i've had it for a month now and put 200 miles a day on it and it's done it 3 times,someone said to replace the oil pressure switch,which i haven't got around to yet .

[eracers999]

OPS cured my same problem. That dont mean it couldent be the lift pump. Easy to check.
Kent

[Andy Chesek]

Thanks for the response, I'll check that out and report back.

[Andy Chesek]

Swapped the OPS yesterday, and the truck seemed to run better.

Coming back from the All-Truck Nationals in Carlisle today, the hiccup came back as I passed someone on I-76. *grr*

[charliepeterson]

The "hiccup" is most likely a fuel issue. With the truck running check for 12 volts down at the lift pump under your seat on the frame rail.
Since you replaced the OPS I bet you have the 12 volts.
If you open the "T" petcock at the thermostat with the truck running you will see fuel come out of the rubber hose. If you don't, close off the valve before the truck stalls. The lift pump must push the fuel up to the Injection Pump for performance and to keep the IP from overheating. The fuel flow is all the help it gets.
I bet the lift pump might have locked up and isn't pushing any fuel.

[Andy Chesek]

I swapped the lift pump out, and I'm pleased to say that fixed the problem. For good measure I replaced the fuel filter, even though it didn't look that bad.

Truck runs real smooth now, thanks again for the help.

[Andy Chesek]

Bah, hiccup came back today after running for a while. Therefore, I recind previous post.

New OPS, new filter, new lift pump. Truck does run better, and it seems to take longer for the hiccup to occur. What should I check for next? FSD? And if FSD is next target, is there an easy way to test that?

[jspringator]

How old is your PMD? The 99's have a solenoid system to drive the lift pump which reduces the likelihood of an OPS failure. Changing the lift pump at anything over 100,000 miles is good PM. I had some pretty erratic operation before I changed out my PMD.

[eracers999]

See the post from Greengiant; Resolved, skip and miss under light throttle. Its on the front page.
Kent

[Andy Chesek]

New variant to consider :(

Two nights ago I was driving to work, then out of nowhere I heard a "ching." Often when I stop my truck, or just fire it up and idle, it sounds like something is rumbling around down in the tranny area. Tonight it got worse and started rumbling while in 2nd gear and reverse. If I rev the engine while in neutral, the clutch pedal vibrates. Then, on the way home from work this morning, I pushed the clutch pedal to disengage the clutch at a stop sign, and the truck lurched forward like the clutch never disengaged. It appears I've got a problem with my clutch... it's a LuK, had it installed 6k miles ago.

So, I'm guessing what caused the "ching" is a spring and that's rumbling around. Question is, could a failing clutch setup theoretically be responsible for my random hiccup? If not, I guess I have two problems to deal with now.

I enjoy the truck for the most part, but lately it's just nickel-and-diming me to death.

Yesterday I went to a local dealer and test drove two used Ram CTD's. One manual, the other auto. Both felt like slugs unloaded to my 6.5L, but the auto was something of a refreshment. I'm considering selling my truck before it bites me again. Sorry for the rant...

[Andy Chesek]

Problem got worse over the weekend, and my the Check Engine Light came on. Took it to AutoZone, and came back with DTC P0238... too much boost. I backed off the spring on the TurboMaster, and had the codes erased. For the past two days the truck has run alright, although I miss the power from the extra boost. Guess I need a few things... gauges.

I followed the instructions when installing the TurboMaster, and set the spring according to instructions...

[Turbine Doc]

Install a boost fooler after you install gauges and you will be able to crank your boost back up some, overboost is one problem, but next one is high IAT from elevated boost levels 10+ psi, you will need IC or WMI for that

[Marty Lau]

Originally posted by 93_Burrito:
Problem got worse over the weekend, and my the Check Engine Light came on. Took it to AutoZone, and came back with DTC P0238... too much boost. I backed off the spring on the TurboMaster, and had the codes erased. For the past two days the truck has run alright, although I miss the power from the extra boost. Guess I need a few things... gauges.

I followed the instructions when installing the TurboMaster, and set the spring according to instructions... I installed the TurboMaster per instruction installed gauges like week later and guess what boost was not the 7-8 psi but 10-11 PSI so the measured space is just an aproximate.

Also if you do go buy a Dodge CTD DON'T get the Auto transmission they don't hold up behind the Diesel.

[Andy Chesek]

Not sure what I want to do with the truck just yet. I had put it up for sale on AutoTrader before I fixed this problem. Still have something going on with the tranny/clutch... got some rattling.

I've driven several Rams over the past week. Some older 12v Cummins trucks with both automatic and manual, and a couple 24v'ers with the automatic and 6-speed. I know Dodge autos have a garbage reputation, but you could look at it as a tradeoff. Here, we find ways to keep the 6.5L from blowing apart while the trannies are okay, and the Cummins rocks but you need to address both the manual and auto trannies (NV4500HD in Ram loses 5th gear..., early 6-speeds had bad syncros), except the later 6-speeds are about bulletproof.

I really dig the simplicity of the 12v Cummins. It's cool to pop the hood of a truck and not see a fuse/relay center. Only electrical stuff you'll find are a pair of batteries and some headlights. It's just so bare in there, and looks to be a piece of cake to do any kind of work on one.

The 24v doesn't look much different, but where I like the trucks with this engine are the other options the trucks have... 4-wheel disc brakes, hydraulic brake booster, ABS (well, it's there but I could do without), 4-door extended cabs, 6-speed...


The 6-speed is very cool. It doesn't have a big gap between any gears like my NV4500 has between 3rd and 4th. And the Rams have a Dana 60 up front and the intercooler. I have a Dana 60 and a Ram intercooler, too. Just don't know if I want to keep the truck and install them now... decisions, decisions...