DBW Throttle Issue

[Jesus-Ninja]

I'm doing a 3UZ transplant, and the donor had a funny issue. It runs, but if you stab the throttle it coughs and bogs. Engine is now running independently from the body loom, and having pulled the inlet snorkel off, it's apparent what the problem is.

The engine will progressively rev, all the way to WOT, but just beyond that point, the butterfly drops closed. Engine is of course completely DBW (potentiometer on the pedal).

I'm assuming that this is some kind of fail safe, and that the pedal sensor is winding round too far.

 

[Zuffen]

I have DBW on my LS3 powered toy and the pedal potentiometer is adjustable, so I would assume your's would be to.

This may improve the engines response as you crack the throttle open.

I know playing with mine did and it didn't affect the idle.

 

[George_R]

It costs $50 or less (with proper skills) to have a scanner . It usually gives more precise and quick answers than the interweb.

The pedal sensor for LS430 is costly and is not adjustable (it isn't adjustable even on LS400). If it begins to play up, bin it. Occasionally I found out that electronic accelerator pedal from mazda rx-8 is perfectly compatible with any gen. LS430. So I assume some other units are compatible too. In fact, simple electronic converter can be made to couple any pedal with any ECU, but that affects safecty and I would never risk on saving a couple $ here.

 

[Jesus-Ninja]

Thanks, guys. Is DBW delete pretty straight forward? If I fitted a cable operated TB, then I just have to make the TPS work? I won't need CC on this.

 

[sideshow]

deleting dbw is probably a huge job
ecu has a million settings for it so if one is out if will shut throttle down
just save the cash and fit aftermarket ecu
or get a scanner and read data
trying to guess whats wrong is like u trying to guess how long this rope is I have in my hand

 

[Jesus-Ninja]

I'm surprised that the ECU "cares" about the pedal position for fueling and ignition. I would have thought it took the signal from the TPS / MAF for that. I thought DBW was more to do with CC control and VSC.

 

[George_R]

Read toyota's official training documents, they are available officially at Techinfo (and at other places like autoshop101, unofficially).

I'm with sideshow on the extreme difficulty of fitting cable throttle with factory ECU. Also note that even if you run aftermarket ECU and fit cable throttle and separate idle speed controller, your auto transmission will not last for too long b/c factory ECU closes the throttle upon each shift, like on the picture below

 

[sideshow]

don't fk with something Toyota has spent 10 years perfecting hehe

manufacturers went to dbw so the ecu has control over the throttle not the person
pushing on the accelerator pedal

 

[Jesus-Ninja]

Cheers - will do some logging.

No autobox though