General Supercharger Thread

Not sure

 

@JustDSM

 

Drove the BMW in 110 degrees to the pool store a mile away, temp elevated slightly so I opened the hood & the lever was super hot because the filter for the SC oil landed right under it so I stole a page from Rey's book. & while I was there.....

 

I'll preface by saying that I'm not absolutely certain that what I experienced was due to vapor lock, but until I can determine otherwise, it's what I'm going with. I'll also apologize in advance for being verbose, but I like to include details.

Recently I was traveling north on I25 from Pueblo, CO which is a slight incline over a long distance, traveling between 80-85mph while passing a long line of traffic. It was about 21:30, ambient was 75º, boost between 2.5-4psi, throttle enough to stay in PE, and all of this for a duration of 6-7 minutes. TC at 190º, ECT @ 208º, and B1S1 cat at 1,560º. Mind you I had been driving the truck for the previous 6 hours strait (thank you 38 gal fuel tank swap). My fuel level was just over 1/4 of a tank. While making this extended pull, the truck eventually fell on its face! I let off the throttle then slowly eased back in - the truck could maintain a lesser speed but would stumble if I got close to getting out of vacuum. I was monitoring the SG3 and saw STFT max out at +20 and AFR hit 19! Until I could get to an exit, I found that modulating the throttle to stay in vacuum allowed me to keep the truck moving, but any more demand on the fuel system and the truck went back to stumbling and sputtering.

After pulling off the interstate and letting things cool down a bit, I got going again, eased into the throttle and stayed @ 75 mph doing my best to stay in vacuum. After another 25 miles or so, it started doing the same shit again. I feathered the throttle enough to get me to a gas station. I checked under the hood for anything suspicious, topped off the tank, and sent it. No problems at all for the next 40 miles home. I even put my foot into it a few times the closer I got to home, just to see if anything changed.

I never had problems like this before with the truck. However, I was able to duplicate it last weekend driving to Utah for a dirt bike trip. I've made this same 350 mile trip dozens of times, problem free. But this time I was prepared for the worst. Towards the end of my journey, there's a long stretch of highway where at 01:00 no one is around - so I thought this is my chance to test my theory about vapor lock. Truck was somewhat hot, ambient was 72º, fuel is likely warm (I had 1/4-1/3 of a tank), time to open it up. I was already doing about 75 and got it up to 100 for a bit - cat temps got to +1,500º, TC 185º, and ECT at 205º. Nothing happened. Coasted to 70mph and went to do it again. This time I slowly eased up to 90mph when I got into boost and BAM, it stumbled! Same STFTs and AFRs as the last event. I pulled off the highway, popped the hood to let things cool, and fueled up with the 15 gal of extra fuel I had with me. Eventually got going again, and made it to my destination problem free. I'll note that several days later, my drive home was very cool and rainy and fortunately anticlimactic.

My suspicion is high fuel temps leading to vapor lock. I had experienced similar with my +400whp MR2 - the cause was a faulty high-flow Walbro fuel pump plus anything less than a half tank of fuel with hot ambient temps. For the uninitiated, a MR2 is mid-engine and the fuel tank is situated in the middle of the car between passengers, under the shifter. The radiator lines traverse the car and rest right next to the fuel tank too, with all this is encased by paneling under the car. The floor gets really warm, so I can only image how warm the fuel gets. What would happen is the fuel pump would easily get hot and heat the fuel along with it. Any real demand for fuel and the car would sputter and die until things cooled off or I topped off the tank. Aside from running straight up E85, the fix was a new fuel pump and insulating the fuel lines in the engine bay. Haven't had a problem since.

As I mentioned in my post about the Mishimoto thermostat, I experienced higher component temps after adding the RCI skid plate over the winter. What I haven't mentioned is that I am running OEM style Magnaflow cats, after having my OE cats stolen. These new cats do not have heat shielding like the OE did, and they also don't have as good a fit as OE does. Bank 2 rests on the crossmember supporting the transfer case, and bank 1, the real problem, sits uncomfortably close to the fuel lines with only a small piece of insulation - on the fuel lines themselves - separating it from the first cat. With the increase in ambient temps, the RCI skid/cat shield preventing cooling, and having a 38 gal tank that sits very closely to the 2nd unshielded cat on bank 1, I believe this is a recipe for hot fuel and it doesn't take much heat to turn that fuel to vapor.

I'm installing the full SPD exhaust today. The hope is with one less cat on each bank, and a better fit and finish than the Magnaflow, coupled with the Morimoto thermostat, that I won't have these problems again. I have an Innovate ECF-1 arriving at some point, that will provide fuel pressure AND fuel temps, which will be a great help in monitoring the goings on with the fuel system.

 

Another nice detailed write up. When I switched to AN braided fuel lines I put heat shielding sleeves all along the drivers side as it was close to my headers and exhaust. Maybe needs some extra shielding if it persists. Hopefully the spd and t-stat is the ticket.

 

I didn't think you could get vapor lock with a return-style fuel system? I thought that was only a dead-head fuel system thing?

 

This honestly could just be a long grade at 1/4 tank causing fuel starvation as several of us have saw. My 26 gallon stumbles around 1/4 on extended accel runs and a grade would mimic the same conditions. I've heard the 38 gal tanks are similar and potentially worse for when they start starving for fuel.

 

Details are good.

Not to discount vapor lock. Leads me to believe something else is the cause after you topped off and the symptoms went away.

I've had fuel cut off at low tank levels from the fuel sloshing away from pump; incline or rapid acceleration. Something to consider.

A quick gander at the vapor lock symptoms posts here regarding Tundra are mostly about not starting in hot conditions. I didn't find any with a thermostat fix.

 

Fwiw, one of my experiences (and logged) was very similar in sound, and it was only after I stopped for fuel and clearly didn't idle things long enough. Trans temp and ECT were both at 221* at startup, I idled a bit more and the hit the highway to continue my mountain climbs. It was pretty weak and there was nothing I could do to wake it up. Jesse @TurboKits.com is chewing on all of the logs and has some ideas. Could be a high temp tables or something else. I'll be expanding the logging to include more transmission data points.

Those enhanced logs will be captured in just a few days, so please keep in touch. I'm doing most of my reporting in the turbocharger thread if you aren't also flight following there.

 

Holy sh¡t ! How did you guys remove the lower header exhaust bolts? Damn things are STUCK and in using an impact gun!

 

Send us an email, and we can chat.

 

One thing to note on the ATI pulley, or at least XAT's version, is the stock pulley bolt doesn't fit...you have to grind the washer down about .1" all around. I held the washer with vice grips and used my grinder with a flap disc to get it down to size.

 

We don't use salt out here and mild winters...but lots of pb blaster or good penetrating oil.

 

Nice! I was looking over their nice to haves for a built engine...someday!

 

All reasonable and plausible points. And like I prefaced before, I'm not absolutely certain it was vapor lock but here's why I'm willing to defend it:

The only significant variables that changed recently were temperatures, both ambient and component (engine, trans, & cats). These significant component temp increases occurred after adding the skids and cat protectors in December, and up until the past three weeks, I haven't driven in anything over 70º, since late last summer. I have allowed my tank to drain to nearly empty multiple times - in fact, I do most my of testing/tuning at a quarter or less - and have not experienced any hesitation or stumbling until recently. I swapped to a 38 gal tank last August.

@armyoffoo you're absolutely right about not getting vapor lock in return style systems. I know vapor lock is a term from the good ol days of carbs and mechanical pumps on or near the block, but it's the only automotive term I can think to use to describe an intermittent vapor bubble in the fuel line. Because it is a return style system, the vapor bubble doesn't lock out the rest of the fuel and completely stall the engine, but rather cause it to momentarily starve and stumble.

@VWTim I would really like to believe the answer is starvation at the pump due to fuel level or proximity and I haven't completely discounted the idea, but it's never done this before, even under similar circumstances - low fuel, traveling on a grade and/or under boost. Being that I was able to duplicate circumstances from my first event - low fuel, hours of driving, warm ambient temps, and hot component temps, I was able to get it to hesitate and stumble once getting into boost and PE. The only difference was that I was not on any incline and my acceleration to 90 was very gradual, in hopes to not slosh fuel away from the pump.

Aside from my MR2 struggle, I witnessed something similar on a buddy's rock crawler. He had some small EFI 4-banger longitudinally mounted just before the rear axel and behind the cab. Above the header was the muffler and above the muffler was his fuel cell. Every time we'd go wheeling on a hot day, towards the end of the day the engine would hesitate and almost stall whenever he gave it the beans. We couldn't figure out what the hell it was until he added a FP gauge near the regulator. Turns out fuel pressure would drop when the fuel cell was around 1/3 full or less and very hot due to its location. He eventually put some heat shielding along the fuel lines, between the engine and fuel cell, as well as wrapped the headers and exhaust - he never had a problem after that.

All this, just theory based off experience and deduction. I plan to do more experimenting, especially once I get the ECF-1. I'd like to know for certain what it is.

 

Downpipes!!!

Amazingly well packed, they look amazing. If the pre '14 issue is in my '13 what do I need to look at to see if they will bolt in or I need a shop?

Thanks Rey & SPD!

 

Another hurdle I just encountered after installing the hub...the damper won't slide over the hub because it interferes with the oil pressure sensor...so I guess I'm moving that now...

 

Those look nice! They do fine work, I can't wait to get my cat-back connected up. Take the pipes under the truck and see if they look like they bolt up.

 

I have done 1 Transgo VB kit before. Wasn't too hard but never drilled or reamed it. I looked up all the kits available and it looks like there are 4 kits. The instructions for the drilling and reaming look straight forward and kind or hard to mess up it looks like, but I get what you're saying. Priced them out and it's a round $260 for all 4 kits. I really dont have the luxury of having my truck down, can I work around it, probably. I have to look into/consider my options.

 

I believe Prospeed uses the kits for their VB upgrade. Saw a pic with the transgo packaging and instructions on the table while they were doing the VB mod. Decent instructions and several videos out there. It always comes down to the time to get it done.

 

I think they plan on offering them in the future, if and when they release their upgraded transmission.

Soon "TM"

 

Yup forgot they are not out yet.

I think cooling in summer should have no issues regardless of where you live. Winter is where we would need to pay attention to get it up to temp.

 

I was looking at some of Johns videos and he mentioned Sonnax which I forgot made trans kits also. I when to their site and for what they call a Zip Kit. It apparently dares som/all the problems in our trans. It also Has one of the acuu pistons John talks about. Anyways that kit requires no drilling or reaming. I only have 40k on my truck and I think if I do the zip kit now, it will take care of the main issues. Something else to ponder about buying now.

 

I also noticed the Zip Kit but have never seen anybody talk about it or provide install feedback for it. Wanna be the guinea pig? Ha.

 

Sonnax is very well known brand for trans kits. Since I only have 40k on my trans and probably 2k since the SC, I think my VB parts should be new and no need to drill or ream out. I have to double check the parts in the Zip kit to the parts Transgo sells. I did notice that Sonnax sells regular and oversized parts, didn't see that with Transgo.

 

If you get the p2757 the TC port on VB accumulator needs to be reamed for the larger one. It's a good idea to tighten up the trans cause if you get the p2714, delay in shift stuck off, could be needing a rebuild. I got the p2714 but it cleared and did a drain and fill. I'm ok as I know I got some hard miles on the trans. Hoping it might have been some debris on solenoid..
Nice find as I missed the info that kit.

 

Liquid wrench for 2 hours

 

Said fu¢k it and went it and had a tire shop break them loose and snug them up. No charge. Came home and got it done.

 

I relocated my stock oil sensor and installed my AEM oil sensor while I was at it, parts list below. I didn't have to adjust the wiring, plenty of room for the balancer now...and a larger crank pulley when the time comes.
1/8BSPT male to 1/8NPT male adapter from McMaster Carr
1/8NPT Tee adapter from Earls
1/8NPT male to 1/8BSPT female adapter from Earls

 

Ah, I wasn't very clear about that. I'm familiar with Sonnax, I just haven't seen a lot of feedback on Tundra specific Sonnax kits like the one mentioned.