Sorry this is long, but Iím trying to give as much detail as possible.
Iím having 2 problems with my truck. It stalls randomly, and itís lacking power. Iíve been trying every diagnosis I can think of, and I need some new ideas of where to look.
First the stalling. The truck will die and/or have a no start situation that is exactly like a CPS issue. When it wonít start back up, there is no smoke whatsoever while cranking. First thing Iíve tried is CPS. Iíve replaced it 4 times in the past month, and still having the same issue. 3 times I replaced the CPS, the truck started up. However just yesterday I put a brand new one in and the truck just cranked and cranked. Iíve also tried unplugging the ICP sensor to get the truck to start with no luck.
So, Iíve had no start issues with new CPSís, and also with the ICP sensor unplugged. I think Iíve ruled both of them out as potential problems. Iíve checked the wiring harness at the PCM and also checked to see if the chip came loose, and no luck. All other wiring harnesses look fine. I canít find any chaffed or loose clips, harnesses, or wires anywhere. Iíve wiggled around every wire and harness I can think of when itís stalled out, and nothing changes.
Oil level in the HPOP is good. Sits about half an inch from the top, and thatís when itís not starting.
As for codes, there arenít any except for the usual ones associated with my mods. Only once did I get a P1212 after a no-start, but that was one time out of countless stalls this past month. It has never popped up again. Iíve tried to keep my laptop with me as much as possible, but the damn truck has never stalled when I had AE with me. I was at the drag strip last Wednesday when the truck stalled driving around the water box. Another PSD owner had his laptop, and by the time we got it hooked up the truck started. So again no diagnostics to go by. Every test that I have run with AE the truck has passed with flying colors.
Now for the loss of power. As I mentioned I was at the drag strip on Wednesday (Bandimere near Denver). This year I was slower at the same track than last year. Here is the difference, last yearís mods were:
- 4Ē exhaust
- Homemade Intake with the Napa 6637 filter
- 36Ē tires w/ stock 3.73 gears
- Stock tranny with Sonnax valve and spring kit
- Hutch and Harpoon mods
- Best time of 16.1 @83 MPH in the 120 race setting
This yearís additional mods are:
- Same DP-Tuner
- Regulated fuel return
- GTP38R ball bearing turbo
- BTS transmission
- 4.30 gears
- 6.0L intercooler
- AFE Stage II intake
- LL #8 injector replaced with a stock AD
- Non ebpv plate and pedistal
- Best time of 16.2 @ 80 MPH in the 80 econo setting
The 120 race setting gave me a worse time of 16.4 @ 80 mph, and that run on the race setting had the best launch of the night. Hereís what I know, my stock HPOP is weak, and can only maintain just over 2100 psi of oil pressure at WOT on the 80 econo tune, and around 2000 psi on the 120 race setting. However, this is nothing new, and itís been like this for a long time (including last yearís races). I figured this year I should have shaved off a tenth or maybe two with the help of the BTS tranny, gears, and possibly the turbo. Iím running higher boost and lower EGTís than last year. Last year I maxed out at 28 lbs of boost at the track on the stock turbo compared to 32 lbs on Wednesday with the ball bearing. EGTís last year were 1450 at the end of the strip, with this year never even reaching 1300. 60 ft times last year were 2.3ís, and this year was 2.1ís.
So, Iím at my wits end here. Iíve checked for boost and exhaust leaks and found nothing. Fuel pressure is bumped up to 70 psi, and no fuel leaks or problems. Fuel filter is new, oil is synthetic and pretty fresh. This truck has been very well maintained, and the stalling issues only started up a month ago. Daily driving is normal, other than the stalling which is suddenly getting much worse this week. Started off stalling once or twice a week, and yesterday it stalled 3 times in a row then ran fine for the rest of the day. I canít drive my truck anymore for fear of getting stuck somewhere bad (like an intersection). Can anyone give me any other advise on what I should be looking for? I will again drive around this week with my laptop in hopes of catching it when it stalls and reply back here with what, if anything, that I find. In the mean time, Iíll be seriously looking at your responses.