jwahaus

I installed a supercharger on my 2002 Tacoma 3.4L last weekend and have noticed some strangeness.

Between 2700-3500 RPM I get a significant loss of power and the engine studders. It is much more prevalent under a load (in 2nd or 3rd gear). After around 3500 RPM's I get a surge of power and have good pull and performance all the way to red-line.

The trouble is only between the RPM range above. Above and below this range the engine pulls hard and smooth.

Any ideas on what could be causing this and how to correct it?

Also, worth mentioning is I also installed the 7th injector kit with TRD ECU.

One thing I thought was strange (and almost didn't do it) is that during the 7th injector install they have you disconnect the vacuum hose from the Fuel Pressure Regulator to the Supercharger and move it (using a newly supplied hose) to the silencer on the intake. What is the purpose of that? I'm tempted to move it back.

Any advice is appreciated.

Cheers,
-Jeff-

Good Times

Jeff:

I don't know much about the SC's but Gadget here is our local SC expert. You should give him a PM or something and ask him as I'm sure he'll be able to give ya a pretty good direction.

http://www.gadgetonline.com

Also that's his site so you might find some help files there.

Good luck

MTL_4runner

Try the search button, there are thousands of posts on this in here.

jwahaus

>Sorry but use the search button, there are thousands of posts on this.

I have searched and read through the various problems people have reported with a SC install. I have not seen any posts that specifically address the problem I've described.

The "lean out" problem that seems to be popular I'm not sure fits the bill. I don't have loss of power at high RPM, I have it at mid-range RPM. Once I get above 3500 RPM's something magical happens and I get smooth and strong power. If it were a lean out problem I would expect it at high RPM's.

Also, the 7th injector kit should take care of the lean out problem.

It does seem that either my air/fuel or timing is off between 2700-3500 RPM's. I could hear some pinging under heavy throttle when I'm within the "bad zone".

cstary

don't worry about that "use the search button" comment - you deserve more than that here . . .

question for you: did you install the 7th injector after running the s/c successfully for a while? just trying to nail down the source of the problem a little bit.

did you install the s/c and/or the 7th injector yourself?

also, do you have any guages installed? like an Air Fuel ratio sensor?

it sounds like under boost at low RPM you are too rich, and it probably has to do with a tuning problem with the 7th injector ECU. if so, i'm sorry to say that this might be a contact-TRD problem . . . .

creed

MTL_4runner

It was not intended as an insult....just a starting place.

You could consider getting an OBD II interface so you can see how rich or lean you are running. You need one that reads the O2 sensors. You could also get a separate wide band sensor but they are very expensive still. I like the one in my sig and have used it very successfully.

There is this one as well if you have a laptop:
http://www.obddiagnostics.com/

It is tough to speculate on the problem without knowing any feedback from the system.

jwahaus

Okay, I checked over all the vacuum hose routing today and found something.

I had neglected to install the vacuum hose from the supercharger near the inlet attached to the throttle body on the back side to the Vacuum Throttle Opener.

Dooh!

I'm not sure what this does but it did seem to improve things. I guess now I need to drive for a few hundred miles and let the ECU relearn (and try to forget about the previous bad setup)
Too bad there is not a way to tell it to forget what it learned over the last 300 miles.

I installed the SC and 7th Injector myself and at the same time. I wanted to take advantage of having everything pulled apart so I didn't install them one at a time. It would be nice to have a full set of guages but I probablly won't get them unless I continue to have trouble.

I'm still curious as to what will happen if I move the Fuel Pressure Regulator vacuum line back over the the supercharger. I'm not going to try it unitl my ECU has had a chance to adjust to the new changes though. I wonder why they have you move it during the 7th injector install.

Anyone have some insight on this?

MTL_4runner

You can reset the ECU by disonnecting the negative on the battery or pulling the ECU fuse.
Glad you figured it out.

Gadget

You can use a NOID light to see if your power loss is happening when the 7th injector is turned on. If that is the case it maybe going super rich and killing power. To bad you can not adjust or retune that thing to work properly.

Gadget

www.GadgetOnline.com

jwahaus

>To bad you can not adjust or retune that thing to work properly.

One of the things that appealed to me with the TRD kit was that it was a out of the box plug and play solution.

With the proper installation there should be no need to tune anything. Not that I'm opposed to tuning, I just didn't want to have to spend the time since the truck is my daily driver.

Hopefully with the vacuum lines corrected everything is working as it should. I reset the ECU and now just need more time to drive it and evaluate the performance.

The RPM range I was having trouble with before in 2nd or 3rd gear with my auto-transmission means that "hauling ass" is pretty much required to evaluate the fix.

kimchee

Sounds like we have the same problem except my lines are all in the right place and i still get these problems.


surging, pinging, flat spots

I also have the 7th injector kit installed.


My guess is that the TRD ecu is not very well mapped.
Ive had my kit on for over 700 miles now and its still this way.


Did you use 1 step colder plugs? did u use the trd thermostat?
Im going to try different plugs. to see if the pinging goes away.


Also the line from the FPR to the boost port is essentially gadgets free FMU mod that TRD seems to have added to the instructions in later supercharger manuals.

If you are still using the stock fuel pump Id leave it on the boost port. If youve upgraded fuel pumps then I think returning it to the ISR wouldnt make a difference. Leaving it on the boost port isnt going to hurt you at all.

David

Gadget

Of course you are going to hear more about what does not work well then what does, but I have been getting lots of emails from people with the 7th injector that are having the typical hesitation, rough idle, surging and so on with the TRD thing. Some have bought upgraded fuel pumps from us and they report that it works better with the new pump then without. Some are and have ripped out the TRD thing and replaced it with the URD kit. Others have ripped out the TRD controller and replaced it with an aftermarket additional injector controller that is user tunable with a very good result.

We are having a special box made that will replace the TRD controller with ours that will have full control over fuel and timing for folks that want to get rid of the problems they are having with the 7th injector.

So, some people are in fact having lots of drivability problems with the 7th injector and others find thier's works great. To say that the TRD thing is a true plug and play installation does not seem to be the case for everyone that buys one.

You might want to check out some of the more recent posts on Tacoma Territory on the subject. You might find many of them a bit harsh about the 7th injector.

Gadget

www.GadgetOnline.com

ManyMods

Don't feel badly about your oversite, the Toyota installer left that vacuum cap off of mine. However, the lean condition created by the open port caused a diagnostic code light. For me, the one-step colder plugs helped and I just installed the Walbro pump, just for the hell of it. I can't say it runs 100% but it doesn't ping under any condition and driveability is good. Disconnect the negative battery to reset the ECU and then go out and thrash it.

jwahaus

Yes, I installed the recommended Iridium plugs and gapped them to 0.032"
I also installed the TRD thermostat. Both of these were installed at the same time as the Supercharger and 7th injector kit.
I took advantage of having the intake manifold off, there was plenty of room to access the plugs. Seems like it would be a real bitch to change the plugs on the passenger side with the SC and throttle body in the way.

What year and model truck do you have?

There seems to be a lot of variation year to year and between models. For example the sensor on the drivers side I was supposed to remove was not there on my engine. On mine I have 3 sensors located on top of each of the passenger side plugs.
Anyone know what these sensors do?

Each year also seems to have a slightly different factory ECU.

jwahaus

I had read about the possible fuel pump inadequacy but I was pretty sure this was not my problem as at high RPM (above 3500) I was getting great performance all the way to redline.

Since I've added the missing vacuum line I havn't noticed any problems. I've only driven about 5 miles since then so it is really too early to say if everything is working perfectly.

I wonder if the problems people are reporting are specific to a particular year or model. Have you collected any statistics on this?

Of course another thing that is impossible to tell is if everyone that is reporting problems has everything installed correctly. The install instructions do leave out a lot of the details in some places leaving one to figure it out for themselves.

MTL_4runner

Those are ignition coilpacks which generate the spark for firing each plug.

ManyMods

[QUOTE]Originally posted by MTL_4runner
Those are ignition coilpacks which generate the spark for firing each plug. [/QUOTE

Speaking of plugs, I did not use iridium plugs, I used NGK BKR6EKPB-11 (Stock# 3452) gapped @ .035". Changing the plugs on the 2002 4Runner is easy.

jwahaus

Update:

Okay, it looks like the missing vacuum line was the only problem I was having. After around 200 miles of driving I now get smooth power throughout the entire RPM range.

I'm very pleased with the TRD supercharger and 7th injector kit as a whole.

Now I just need to give my setup a little more sound. The stock exhaust is just so quiet. The whine of the supercharger gives the engine an almost electric sound.

AJatx

Glad you found the root of your problem.

For those pinging, what kind of climate conditions and altitude do you reside? I would imagine that TRD would be prudent and have the ECU on the rich side so there is margin for folks who live in different climate conditions.

Remember that being on the rich side can cause stumbling and bad idle. Also, running rich will stink more and at times leave residue on the exhaust tip.

Wideband O2 analyzers are getting cheaper these days and it may be wise to purchase one for tuning and debugging. I believe I've seen some as low as $500 for the whole kit (wideband O2 sensor, controller w/ temperature feedback and data interface, and cabling).

Most wideband O2 sensors will be NTK11 (Uego?) or LM11 (Bosch).


J

jwahaus

Ajatx,

How do you like the sound of the TRD exhaust? Do you also have the headers or just the Cat-back?

I was wondering if you could install just the exhaust without the headers.

I'm looking for a little rumble without being obnoxiously loud.

-Jeff-