Alright have tried a few different searches and found nothing that fits my particular issue. Relevant Mods are: 560s lex afm, stock pump and regulator 57 trim ct26, boost controller, and wideband. Started having issues boosting after I backed the screw out of the lex afm. My car will drive and idle perfectly but as the boost gauge reads 0psi I see a lean spike along with violent cutout/ bucking loosing all power. In neutral car will free rev fine and no lean issues. Only code thrown is a 51 but it's very intermittent (assuming its ac button related). Checked for boost and vacuum leaks multiple times, found some but fixed them only to see the problem persist. What else would cause this condition/ problem? Fuel pump not switching to 12v creating a lack of fuel? Totally stumped any help is appreciated. Thanks!
Lean, bucking and no power
- Thread starter mkiiibro
- Start date
Your 51 is not AC related but neither will the TPS cause that symptom. It could be the pump not switching. I've seen that twice before. A simple test is to jumper the pump on in the diag block and do a test drive.
alright i jumped those terminals in the box but didn't notice any difference? I also tried bypassing the resistor, as done in the 12v mod, this seemed to make the pump louder. I never noticed a whine before but after having it bypassed it seemed to make noise. Took it for a test drive this way swell, but still seem to have the same issue, although my afr's seemed a little richer but still too lean. I also unplugged the TPS while idling and it seemed to stay idling and rev out fine. Haven't had the tools to test the TPS yet but does that sound as if my TPS is out of whack or bad. Could it be a combination of bad TPS and inadequate fuel?
It could be louder because it is worn out. Nothing lasts forever, entropy prohibits it. Even on a Toyota.
Simply enough to flow check. Iirc the minimum spec is 1 liter/30 seconds but doing a snap throttle test with the regulator off vacuum would be much quicker.
No difference with the TPS unplugged isn't surprising. Most here put way to much emphasis on trim sensors. An important thing to remember on these engine is, barring problems like fuel pressure, induction leaks, bad injectors, etc the TCCS is easily capable of getting the mixture within 1% of correct with nothing more than load and speed. Seems a lot of folks either don't know or forget that and make troubleshooting way more complicated than it needs to be. Not that the EFI system is usually at fault anyway, because it's not.
No difference with the TPS unplugged isn't surprising. Most here put way to much emphasis on trim sensors. An important thing to remember on these engine is, barring problems like fuel pressure, induction leaks, bad injectors, etc the TCCS is easily capable of getting the mixture within 1% of correct with nothing more than load and speed. Seems a lot of folks either don't know or forget that and make troubleshooting way more complicated than it needs to be. Not that the EFI system is usually at fault anyway, because it's not.
