RESOLVED: S/C Installation Prob, Rough/High Idle Issues and Rats (Code P0125)

[alphyn]

I self-installed the S/C kit a few years ago, and added on the URD 7th injector kit to boot with the smaller URD pulley for more boost. Truck was running OK until I let it sit while away for work for 2-years.

Installed items included:

• Upgraded fuel pump.
• Cooler spark plugs.
• Supercharger.
• 7th injector.
• URD control module.

Quick note: I reused throttle body and intake gaskets when installing the S/C.

Issues I'm experiencing:

• high idle - approximately 1500 RPM when engine is warm.
• CEL after engine warms up.
• Blinking CEL when revved above 4k under moderate acceleration. Engine doesn't sound like it's missing or act sluggish.
• Rough idle - solved with MAF cleaning, no longer an issue.

I had the CEL checked before and I was getting lean codes. I'll be investing in a reader soon enough to confirm codes.

Checklist of remediation steps I've taken:

• Visually inspected all vacuum line hoses and tightened up a few connections with clamps that looked loose.
• Cleaned MAF - solved rough idle prob.
• Re-tightened throttle body and intake manifold/SC bolts to spec.
• New tank of fresh gas.
• Visually inspected all air intake piping and connections.

Things I thought about doing but haven't yet (other than take it in for a pro to work on):

• Test fuel system pressure.
• Smoke test vacuum lines.
• Remove fuel injectors and have them reconditioned / cleaned.
• Replace throttle body and intake gaskets.
• Re-do all vacuum lines / hosing.
• Drink a case of beer and stare at the engine for a few hours.

I just moved to California and need to smog / register my truck, so it's just been sitting in the garage as I tinker on it. If anyone has recommendations for shops in Sacramento I could take it to - or any suggestions / feedback what I should do or check next - it would be much appreciated.

*** Marking this as resolved. Thank you all for your help and support. Here's the link to my write-up of what was resolved and how in this thread. ***

 

[Jeffy]

I self-installed the S/C kit a few years ago, and added on the URD 7th injector kit to boot with the smaller URD pulley for more boost. Truck was running OK until I let it sit while away for work for 2-years.

Installed items included:

• Upgraded fuel pump.
• Cooler spark plugs.
• Supercharger.
• 7th injector.
• URD control module.

Quick note: I reused throttle body and intake gaskets when installing the S/C.

Issues I'm experiencing:

• high idle - approximately 1500 RPM when engine is warm.
• CEL after engine warms up.
• Blinking CEL when revved above 4k under moderate acceleration. Engine doesn't sound like it's missing or act sluggish.
• Rough idle - solved with MAF cleaning, no longer an issue.

I had the CEL checked before and I was getting lean codes. I'll be investing in a reader soon enough to confirm codes.

Checklist of remediation steps I've taken:

• Visually inspected all vacuum line hoses and tightened up a few connections with clamps that looked loose.
• Cleaned MAF - solved rough idle prob.
• Re-tightened throttle body and intake manifold/SC bolts to spec.
• New tank of fresh gas.
• Visually inspected all air intake piping and connections.

Things I thought about doing but haven't yet (other than take it in for a pro to work on):

• Test fuel system pressure.
• Smoke test vacuum lines.
• Remove fuel injectors and have them reconditioned / cleaned.
• Replace throttle body and intake gaskets.
• Re-do all vacuum lines / hosing.
• Drink a case of beer and stare at the engine for a few hours.

I just moved to California and need to smog / register my truck, so it's just been sitting in the garage as I tinker on it. If anyone has recommendations for shops in Sacramento I could take it to - or any suggestions / feedback what I should do or check next - it would be much appreciated.

I'm no help with your issues, but I'm curious how you plan to pass a smog test with a supercharger?

 

[alphyn]

I'm no help with your issues, but I'm curious how you plan to pass a smog test with a supercharger?

Here's the official documentation:

PDF of California Air Resource Board approval/exception (Executive Order D-425-4)

Text:
Manufacturer Name: Toyota Racing Development
Device: 6 PSI. SUPERCHARGER KIT
Device Type: Supercharger System / Supercharger Modification
Part_Number: Model_Specification: Modification_Allowed: Remarks:
1995 to 1999 Toyota trucks that are equipped with a 3.4L engine The 6 PSI. Supercharger Kit includes the following main components: Eaton M-62 supercharger, intake manifold, fuel regulator, and all the necessary hardware needed to connect to the stock air filter housing and throttle-body using the stock tubing. No changes are made to the stock ignition system. The kit includes a 2.215" diameter supercharger pulley and uses the stock crankshaft pulley
EO: D-425-4 View PDF
EO Date: 1999-07-29

Several other TRD superchargers / models are listed in the California ARB database:

https://www.arb.ca.gov/msprog/aftermkt/devices/aftermktdevice.php

I know my smaller pulley isn't legal, nor is the 7th injector unit. I might have to remove those when testing, then reinstall. Maybe it will pass the visual inspection and no one will notice, or not.

 

[pauldub]

You might try Valley Hybrids in Stockton. It's probably more of a Land Cruiser place but....

 

[Jeffy]

Here's the official documentation:

I'm an idiot, I don't know what I was thinking. I forgot the older gens have plenty of CARB-legal parts. It's been a long week already.

 

[gamefreakgc]

I'm an idiot, I don't know what I was thinking. I forgot the older gens have plenty of CARB-legal parts. It's been a long week already.

There's a mythical TRD supercharger that's also smog legal for the 4th Gens, but I have never seen one available to purchase. I've looked too... we need a bigger vehicle soon!

I'm not a professional mechanic, but I do know my way around these superchargers. You could bring it by my place, I have a cheapo bluetooth reader and could see what's going on. I have limited tuning experience since I just finished tuning my own 4Runner, I haven't used the Split Second unit but in function it's the same as mine. I'm just up the road in Citrus Heights if you want to stop by, just send me a private message.

The ONLY shop I've ever let touch my 4Runner (too many bad experiences) was All Automotive Services in Citrus Heights. Gardiner does an absolutely fantastic job and does a lot of performance builds. It's funny since several other shops in the area wouldn't touch the header install I was asking for but they referred me to him because they knew he liked challenging jobs related to performance. Nice guy too, the other guy is a bit grumpy but don't be put off by him lol! https://www.yelp.com/biz/all-automotive-service-citrus-heights

 

[alphyn]

I'm not a professional mechanic, but I do know my way around these superchargers. You could bring it by my place, I have a cheapo bluetooth reader and could see what's going on. I have limited tuning experience since I just finished tuning my own 4Runner, I haven't used the Split Second unit but in function it's the same as mine. I'm just up the road in Citrus Heights if you want to stop by, just send me a private message.

That'd be awesome. Really appreciate the help. I'll send you a PM and buy you way too many of your favorite beers.

 

[SCRunner12]

For the high idle I would check the IAC and TPS. I was running around 1500 RPM and replaced my whole throttle body with a used one and it solved my issue. Not sure which one was the culprit, but at 19 years old, some of those sensors might be going bad.

 

[alphyn]

For the high idle I would check the IAC and TPS. I was running around 1500 RPM and replaced my whole throttle body with a used one and it solved my issue. Not sure which one was the culprit, but at 19 years old, some of those sensors might be going bad.

Some updates:

Tested fuel pressure via T-connector I installed as part of the URD 7th injector kit - spliced into the fuel return line. Came back at 10 PSI, well below what I was expecting. I have the Walbro 190 LPH fuel pump installed which should put out over 60 PSI. I installed a new fuel filter hoping that was the culprit. No dice.

Anyone know there's a fuel pressure regular upstream limiting return fuel line pressure to 10 PSI?

Also, just purchased replacement IAR and TPS from RockAuto. Should be here next week.

Getting some advice from gamefreakgc this weekend.

I'll be ready to write my doctoral thesis on 3rd gen 4runner fuel systems after this is over. Maybe...

 

[gamefreakgc]

Some updates:

Tested fuel pressure via T-connector I installed as part of the URD 7th injector kit - spliced into the fuel return line. Came back at 10 PSI, well below what I was expecting. I have the Walbro 190 LPH fuel pump installed which should put out over 60 PSI. I installed a new fuel filter hoping that was the culprit. No dice.

Anyone know there's a fuel pressure regular upstream limiting return fuel line pressure to 10 PSI?

Also, just purchased replacement IAR and TPS from RockAuto. Should be here next week.

Getting some advice from gamefreakgc this weekend.

I'll be ready to write my doctoral thesis on 3rd gen 4runner fuel systems after this is over. Maybe...

That's alarmingly low... did you always have this issue? If it only happened after sitting, the fuel pump might be clogged or the "sock" might be full of gunk. No way you should only have 10 PSI with the 190 on there if it's working correctly.

 

[turbo8]

There is a fuel pressure regulator on the back of the driver side fuel rail. It has a vac line running to it, make sure it is attached.

Also might want to check the vacuum\boost Tee that came with the 7th injector kit. There were some that came from URD that were completely blocked off.

From URD:

URD has discovered a potential problem with our 7th Injector Kit for the TRD/Magnuson supercharger systems for the 3.4L V6 engines.

The kit includes a specially made vacuum T fitting that is used to bring a manifold/boost reference signal to the control unit. The T fitting has a restrictor molded into it to dampen the impeller pulses from the positive displacement supercharger.

We found some T fittings in the batch that were completely blocked off instead of just having a restriction. There is a chance that some of these Ts made it out to customers in kits. If your kit has a T that is completely blocked off it will not work correctly.

We encourage all customers to remove the vacuum line from the control unit and simply blow and suck on it. If it is completely blocked off you will not be able to. If it is correct, it should be hard to blow through it, but you will be able to.

If you find yours to be completely blocked off contact URD Tech Support by EMAIL ([email protected]) including your original order number and current shipping address stating, you have a T that is completely blocked off and URD will get a new one shipped out to you ASAP.

This should only involve a small number of kits shipped from URD since APRIL 2016.



Steve (Gadget) Dopler

 

[alphyn]

We encourage all customers to remove the vacuum line from the control unit and simply blow and suck on it.

Things I did to my 4runner today? Blow job. Blew fresh and clear. Appreciate the bulletin.

 

[wrench.n.wheel]

Jumping into the thread since I'm local and plan to get a supercharger.

Some inkling inside is telling me its the IAC, specifically the motor died and it won't regulate, but then again, the lack of fuel pressure doesn't seem to correlate.

 

[alphyn]

Thread Update - Got Gas Delivery Probs

Some inkling inside is telling me its the IAC, specifically the motor died and it won't regulate, but then again, the lack of fuel pressure doesn't seem to correlate.

That's alarmingly low... did you always have this issue? If it only happened after sitting, the fuel pump might be clogged or the "sock" might be full of gunk. No way you should only have 10 PSI with the 190 on there if it's working correctly.

Quick update to the thread. Big thanks to gamefreakgc for walking me through my S/C installation, running some codes, allowing me to borrow a few parts to pass smog and passing some knowledge on. Also, for showing me his rig and walking me through all his extensive mods. I was amazed how clean his 4runner was and now have a new checklist of things I want to do.

What we/I found out:

• Throwing lean codes. ECU is doing all it can to adjust lean mixture but not enough fuel.
• Misfires on cylinder 1.
• Running rough and ugly right now.
• S/C appears to be installed correctly; no codes for vacuum leaks.
• Validated original fuel pressure reading was taken on fuel delivery line (not return). Pressure reading taken upstream of fuel pressure regulator. Only thing between fuel pressure reading and fuel tank is the fuel pump, fuel lines, fuel filter (replaced). Visually inspected fuel lines and nothing looks bent or constricted.

Next steps:

• Drop the gas tank and inspect Walbro 190 fuel pump. Inspect fuel pump sock and see if it is clogged. Test pump to ensure it is functioning correctly.
• Install new IAC valve and see if that clears up high-idle (arrived today!).
• Take wife to the airport tomorrow and spend the next week working on my 4runner, watching hockey, and day drinking.

Again, big thanks to gamefreakgc for his help. I've been trying to solve this problem the last year by myself and having another T4R member to run ideas by in person was awesome.

 

[Lefty JD]

Quick update to the thread. Big thanks to gamefreakgc for walking me through my S/C installation, running some codes, allowing me to borrow a few parts to pass smog and passing some knowledge on. Also, for showing me his rig and walking me through all his extensive mods. I was amazed how clean his 4runner was and now have a new checklist of things I want to do.



What we/I found out:

• Throwing lean codes. ECU is doing all it can to adjust lean mixture but not enough fuel.
  
• Misfires on cylinder 1.
  
• Running rough and ugly right now.
  
• S/C appears to be installed correctly; no codes for vacuum leaks.
  
• Validated original fuel pressure reading was taken on fuel delivery line (not return). Pressure reading taken upstream of fuel pressure regulator. Only thing between fuel pressure reading and fuel tank is the fuel pump, fuel lines, fuel filter (replaced).
  
  
  
  Again, big thanks to gamefreakgc for his help. I've been trying to solve this problem the last year by myself and having another T4R member to run ideas by in person was awesome.

• 
  
  
  I lucked out and only needed to replace fuel filter when I s/c’ed. I’m local too, Rocklin. Always up to lend somebody a hand etc.

 

[alphyn]

I lucked out and only needed to replace fuel filter when I s/c’ed. I’m local too, Rocklin. Always up to lend somebody a hand etc.

I might have to take you up on that offer one of these days! Might host a BBQ once I have my house in order, too. Always great to meet new people.

 

[alphyn]

Fuel Pump Out - Now What?

Arduous task of removing the fuel pump is now complete. I think I mentally blocked out all the banging and bumping it took to free it from the tank.

So, now that I have the pump out, sock doesn't look visibly clogged. There's an o-ring locking the sock on to the pump I don't want to destroy so I was really only checking to see if there's excess gunk on the exterior of the sock.

Also, all wires / harnesses are in good condition - connections look solid. Nothing looks out of place.

Anyone have any advice how to test the pump itself? I have a multi-meter handy that I absolutely do not know how to use. Pump has positive and negative terminals I can easily plug leads to.

 

[marcus clarkus]

I've never tested a fuel pump but I would think that just connecting it to a 12v source (your car battery) should be good enough. However, I'm not sure if that's bad for the pump to run it dry. I wouldn't run it for a long time because it needs to be submerged in a liquid to stay cool. Also it would make sense to do some sort of volumetric flow test (e.g. see how much fluid it pumps in 1 min, then convert that to LPH), but idk if you would need to run gasoline through it or if water is ok.

I'm useless. Just search "benchtest fuel pump" on google or youtube or something.

 

[alphyn]

Fuel Pump Passed Testing

I've never tested a fuel pump but I would think that just connecting it to a 12v source (your car battery) should be good enough. However, I'm not sure if that's bad for the pump to run it dry. I wouldn't run it for a long time because it needs to be submerged in a liquid to stay cool. Also it would make sense to do some sort of volumetric flow test (e.g. see how much fluid it pumps in 1 min, then convert that to LPH), but idk if you would need to run gasoline through it or if water is ok.

I'm useless. Just search "benchtest fuel pump" on google or youtube or something.

Fuel pump testing completed. I was able to rig 18 gauge leads into the factory harness and connected to a battery. Submerged the pump in a 5-gal bucket of water and connected to a fuel pressure gauge, then ran for 1-minute. Volumetric output is on spec with the 190 LPH pump rating (actually pumped 228 LPH). Pressure reading was in excess of 30 psi - but wasn't totally capped off so I couldn't get an accurate max reading. I'm thinking it was well over 60 PSI. Ran some gas through the pump to clear any water afterwards.

Time to put the gas tank back in and retest fuel system pressure. But that sounds like a job for tomorrow.

 

[gamefreakgc]

Fuel pump testing completed. I was able to rig 18 gauge leads into the factory harness and connected to a battery. Submerged the pump in a 5-gal bucket of water and connected to a fuel pressure gauge, then ran for 1-minute. Volumetric output is on spec with the 190 LPH pump rating (actually pumped 228 LPH). Pressure reading was in excess of 30 psi - but wasn't totally capped off so I couldn't get an accurate max reading. I'm thinking it was well over 60 PSI. Ran some gas through the pump to clear any water afterwards.

Time to put the gas tank back in and retest fuel system pressure. But that sounds like a job for tomorrow.

Wow, nicely done! Wish I was funemployed

So what gives with the fuel pressure then? If you measured 10 PSI at the 7th injector fitting and that's BEFORE the Fuel Pressure Regulator so it rules that out as the problem, why is there still no fuel? I'm really stumped on this one. Are there any kinks in the hard lines or damage? Or maybe the pump is terribly starved for voltage from the wiring?