Engine/Transmission (1998.5 - 2002) Hesitation with no codes, part II

[Little Bill]

I developed an intermitant stumble or miss on acceleration in early October. It only happened when first started in the morning or if I shutdown and restarted before the engine was fully warmed up. I noted the stumble would begin at around 3 PSI boost. Cleaned all connections and moved the pins on the EZ from position 1 to 2 and it improved for a while. It never set any codes. I had kind of convinced myself that it was a temperature related pump timing issue between the VP brains and the EZ. In mid December while driving in a cold rain, it got to stumbling so bad I was afraid I wouldn't make it home. I stopped for fuel and when I restarted the MIL light came, a 1693 companion code was set and it was still stumbling. Got it home and changed fuel filter, removed boost elbow and unplugged EZ from the test port but left it plugged into the MAP sensor as my wastegate was 'tweaked' for 26 PSI without an elbow. Ran OK for a couple days then I pulled out on the highway and no acceleration for a couple seconds. No stutter or stumble, just very low fueling resulting in a long hesitation. This happened a couple more times and on Christmas Eve, with a trailer load of calves, it tripped the MIL light and set the 1693 code again. After Christmas I un-tweaked the wastegate and removed the EZ completely. I've been stumble and hesitation free for several weeks now. Looks like the voltage clamping circuit was failing

 

[Turbo Tim 1]

You need to put a code reader on the truck, the odo read-out does not read p-codes that are not active at that instant. I've had a few different codes come in but most never showed up on the odo. That will tell you alot more.

 

[Cumminpwr11]

I hope that you fixed it, but that doesn't help me any. I been having the same problem, but I haven't tripped any codes. I need to hook mine up to a scanner to find out if they are not showing up like the previous post. I am just keeping my fingers crossed that it isn't the fuel pump failing.



Thanks



Chris



ps NO fuel/timing box. just straight pipe factory pipe

 

[dresslered]

Did any of you get the above mentioned problems resolved? I'm having the same temporary loss of power and then it resumes. The power loss is so abrupt I stopped driving the truck. I did add a DD TTPM (Edge EZ equivalent) about 1000-miles earlier. The MIL light is on and only the 1693 companion code is displayed in the odometer.

 

[Turbo Tim 1]

Originally posted by Turbo Tim 1

You need to put a code reader on the truck, I've had a few different codes come in but most never showed up on the odo. That will tell you alot more.

Not trying to be a wise guy, but out of the 4 or 5 times my MIL came on only once did I have codes show up on the ODO the rest of the times I had to get them read.

 

[dresslered]

Thanks Turbo Tim. That is the same conclusion that I am coming up with. I think that the culprit code clears out before I get a chance to see it, leaving behind just the general companion code of P1693. I'm currently trying to locate/buy an OBD-II scanner.

 

[Turbo Tim 1]

Around me Auto-Zone will check them for you for free but their definitions are usually wrong so you have to go to the manual to find out what is actually wrong.

 

[dresslered]

Thanks again but the nearest AutoZone is 16-miles away. Not that confident that the truck will make it. If I can't locate one for the weekend, I'll try to get one of the local shops to scan it for me.

 

[Little Bill]

2 1/2 months later and still stumble free. No problems whatsoever. I still believe that the ECM was seeing a fast fluctuation of 'processed' MAP output voltage from the EZ.



I don't believe that odometer only reads out codes that are present at that instant. I tripped an 0500 (no vehicle speed detected) by high idling in the driveway 3 weeks ago that took 2 weeks to clear. I've also tripped the 'no voltage detected at MAP sensor' a few years back by switching the ingnition on with the MAP sensor unplugged. That also took a few weeks before the MIL light went out and the code disappeared from the odo.



I do believe that there are some codes like high boost pressure or no vehicle speed that have time periods associated with them before they will trip and store a code. I know first hand that I can overboost to the point that the ECM will begin to defuel but as long as I don't maintain that condition, no over boost code is set.

 

[dresslered]

Did you ever get your EZ replaced and are you running one now? I've heard of this problem before from the EZ and a new box seems to always cure it.

 

[Little Bill]

David,



The EZ is still on the bench and I have not contacted Edge about it. I think I've convinced myself that I don't want the injection timing advanced at low RPMs, but I do miss the extra low end fueling.

 

[HEYBOSS]

Just a thought

It could be a tps (APPS Sensor) I believe it's called!



I know a TDR member that had similar problems for a long time and ran code checks without coming up with any. Ended up being the Apps sensor.



Good luck.

 

[BLucia]

i'm having the same problem at 54,000 miles on my 2001. it will run fine down the highway then out of the blue it will loose power like it thinks the fuel pedal is at idle an then it will read that it isn't and go back to the rpm that it was at. i think it only makes sense that it is the throtle position sensor. i will give it a shot and see if the problem goes away.

 

[dresslered]

As embarrassing as this is for me to admit, I found a faulty connection at the data link. I was very careful to secure everything, allow for engine movement, and even added a drip loop. I am still baffled as to how I missed this the first time around, but it must have been sending an occasional 'corrupt' signal due to the loose connector. I've refastened everything down, and the truck is running beautiful once again. After the 38-mile commute into work, the 1693 companion code as well as the MIL light cleared. I am going to continue to watch this connector. If it loosens again, we might be seeing the addition of MIL connectors.



Little Bill-

I was also concerned with the injection timing as well, and this was the reason that I opted for the DD TTPM over the Edge EZ. It is still manufactured by Edge (same as EZ) but has a more conservative timing advance and different fueling maps. I have heard of many using either box with heavy towing and never having a problem though.

 

[DHoleman]

According to "Superchips " Thier book says code p1693" DTC Detected in Companion JTEC Module" What ever that means, I hope it will help all of you . That comes from my Tuner/code reader from Superchips. It goes all the way up p2609, and can be sent in for an up grade if any come available.

thanks DH