3FE Turbo effect defeated! (1 Viewer)

[Dunbar]

See this post on the 3FE list: http://us.mg2.mail.yahoo.com/dc/launch?.rand=6jrmamue8rp92

I will test more tomorrow but it appears that it is gone and the truck pulls strong throughout the rpm range instead of increasing at ~2300rpm.

I will post a full report here as well after more test driving as some of you are not on the 3FE list. I know several folks have the turbo effect problem both with the A440F and H55F transmissions behind a 3FE.

Cheers.

Dunbar

 

[RockDoc]

Interested to hear what you've done, and what effect it's had.

 

[Spook50]

Never heard of this "turbo effect", though I have felt a surge at about 2300-2500 RPM on a couple occasions. Not a regular thing for me though, so I never paid any attention to it.

Got me curious.

 

[dallen341]

I once had this so called turbo effect in my wifes FJ62 with 3FE. It started when I had a new exhaust system built at a local muffelr shop know for quality work. What happened was they switched the location of the 2 o2 sensors. The one for the front bank of cylinders was mounted in the down tube for the rear bank of cylinders and vice versa.

The real problem came at smog time. The ECM would not adequately control engine emissions this way. Swapping the 2 O2 sensors back into their proper down tubes solved the smog problem and turbo effect.

BTW, the harness was such that I could not just simply swap harness connectors and be done. They were too short to do this.

Don

 

[tonkota]

That link just takes me to my email? Do you have the post number?

OK I found your posts. Yahoo search sort of sucks.

 

[v8tuff]

I too have the turbo effect, haven't watched rpms, but always happens at about 35mph for me. I also have a bad idle, so I always figured it had something to do with air fuel mixture or a leaky intake tube after the MAF sensor. Curious what your fix is.

 

[Moby]

That link doesn't work for me, can you post details of what is going on?

 

[Dunbar]

Original post

Below is my original post on the 3FE list. Several folks here and there have been experiencing an increase in pulling power somewhere in the 2000 - 2500 rpm range. It is as if a turbo kicked in and it started pulling better.

W knew that this was not good as it should be pulling that hard throughout the powerband.

Drove the truck a bunch today and it is running as strong as ever.

Original post:


Finished my injector intall and the turbo effect is apparently gone. I just went on a short test drive up to 60 mph through all the gears several times.

Remember that my main and immediate problem was that my truck was running very rough, it was missing on cylinder #4 for sure. When I pulled my fuel rail the #4 injector came out with the plastic cup attached. Whereas all the others had the cup stay in the lower manifold.

Now I thought that could have been coincidence and it still might, but the truck runs good now. I really think that #4 injector was clogged with crap but it could have been a leak at the cup. The rail is torqued down and I manually rotated all of the injectors before removing the rail and they all moved like they are supposed to, including #4.

Another issue. I am certain that my TPS was out of adjustment before I started all this. I re-adjusted it on the bench prior to pulling the intake. It needed adjustment for sure, not much but it did need it.

So the jury is still out on the turbo effect. It could be just a TPS issue or it could be injector related.

My truck pulls very strong throughout the power band now, just like after I put on the overbored throttle body and new TPS.

Before it suddenly started running very rough, missing on #4, it had the turbo effect where it pulled at a lower level until about 2300rpm. Upon reaching 2300 it would pull much stronger, thus my coining the term, turbo effect. It has been running this way over a year whilst I was too busy to attack the problem. That is until the engine started missing bad.

I will drive it more tomorrow and will report anything new. Right now the idle rpm when warm is still a bit high, ~900ish. Before the missing issue it would idle at 650. I bet I can get it right either by letting the ECU adjust or by adjusting the golden screw but want to wait a day or so.

Dunbar

Oh, and death to bin Laden

 

[BG_TX]

Bump...

 

[Spook50]

Below is my original post on the 3FE list. Several folks here and there have been experiencing an increase in pulling power somewhere in the 2000 - 2500 rpm range. It is as if a turbo kicked in and it started pulling better.

W knew that this was not good as it should be pulling that hard throughout the powerband.

Drove the truck a bunch today and it is running as strong as ever.

Original post:


Finished my injector intall and the turbo effect is apparently gone. I just went on a short test drive up to 60 mph through all the gears several times.

Remember that my main and immediate problem was that my truck was running very rough, it was missing on cylinder #4 for sure. When I pulled my fuel rail the #4 injector came out with the plastic cup attached. Whereas all the others had the cup stay in the lower manifold.

Now I thought that could have been coincidence and it still might, but the truck runs good now. I really think that #4 injector was clogged with crap but it could have been a leak at the cup. The rail is torqued down and I manually rotated all of the injectors before removing the rail and they all moved like they are supposed to, including #4.

Another issue. I am certain that my TPS was out of adjustment before I started all this. I re-adjusted it on the bench prior to pulling the intake. It needed adjustment for sure, not much but it did need it.

So the jury is still out on the turbo effect. It could be just a TPS issue or it could be injector related.

My truck pulls very strong throughout the power band now, just like after I put on the overbored throttle body and new TPS.

Before it suddenly started running very rough, missing on #4, it had the turbo effect where it pulled at a lower level until about 2300rpm. Upon reaching 2300 it would pull much stronger, thus my coining the term, turbo effect. It has been running this way over a year whilst I was too busy to attack the problem. That is until the engine started missing bad.

I will drive it more tomorrow and will report anything new. Right now the idle rpm when warm is still a bit high, ~900ish. Before the missing issue it would idle at 650. I bet I can get it right either by letting the ECU adjust or by adjusting the golden screw but want to wait a day or so.

Dunbar

Oh, and death to bin Laden

Very interesting. I'm hoping once I have enough injectors to send to RCE I can send those and the extra TB in to be cleaned, balanced and have the TB bored over. While they're off I'll clean the extra intake as best I can so when I get everything back I can take a weekend and swap everything out. Hopefully that'll help breathe some new life into my 3FE.

I've never had the turbo effect that you describe, but it seems to me that clean injectors and a properly adjusted TPS are what it takes to prevent it.

 

[AttoirRE]

Checking in and replying to old threads- The injector clear it up for good?