Awkward fuel cut problem.

[IRONMAN]

I'm hitting fuel cut on my car. It is jumpy then cuts off whenever I put my foot down more than 1/4 way or go over 3000 rpm's. If I don't try to push though it takes off as if it is floored. It also has hesitation in the throttle. It likes to act like it wants to die first then take off.

Mods
-megan racing 3" downpipe
-front mount inter cooler, 3" piping
-2.5" exhaust
-spectre big filter
-rebuilt turbo (stock)
-lexus afm

Things tried
-limiting intake flow
-limiting exhaust flow to slow down turbo
-opening wastegate all the way
-adjusting tps
-adjusting cps
-checking for leaks behinf afm, boost leaks, and vacuum leaks

Codes
22 43 41 52

22= water temp sensor open or short circuit
43= tps open or short circuit
41= start signal absent
52= knock sensor short or open

 

[jake8790]

TPS sensor is causing your problems. The other codes need fixed as well. Just wondering, why try all the other stuff when the car has already told you what is wrong with it?

 

[IRONMAN]

Because it is giving symptoms of over boosting too. Whenever it comes into boost it just cuts of and after about a second comes back in and starts going again. I didn't think that the TPS would cause it to fuel cut under boost mainly.

 

[BryanDyer]

well first of all code 52 is part of that problem becuase it richens the fuel mixture when you get that code so it wants to go after 3000 or whatever becuase by then it has enough air coming in to burn the rich mixture or else it just jerks
the tps would also be another problem
when the cars engine light comes on you wanna fix the codes before asking questions or else we can't help

 

[BryanDyer]

and code 52 retards the timing also which also causes the problem

 

[IRONMAN]

The timing is still reading at 10 advanced.

 

[7M4EVR]

Your problem is the Lexus AFM and no 550's with the three inch piping and a big filter to add to the problem.

 

[BryanDyer]

it doesn't matter what the car is reading when it's sitting there idling
it's not like when you drive the car is just constantly at 10° BTDC the ecu can pull/advance timing when it wants and as it feels it needs to which it does when you have code 52
you need to fix all 4 of your codes
you can't expect your car to be running and hitting boost hard when you have 4 engine codes on lol

 

[IRONMAN]

Well was hoping it wouldn't be the knock sensors. It is a GE block so there is only one sensor and two plugs. Is there a way I can bypass it with a resistor to "trick" it into thinking it's ok.

 

[BryanDyer]

no the problem is the engine codes that are on
and it's not a lexus afm it's the housing for the afm from the lexus it won't cause the car to jerk
the tps wil cause it to jerk because it's "not sensing the throttle posisition"
code 52 will make you run rich as it retardant he timing and. not being ableto burn the fuel will cause it to jerk also

 

[IRONMAN]

I have changed the TPS 3 times to see and they all have the same problem the don't connect right. Where could I find test points to see if it is a wiring issue?

 

[BryanDyer]

Well was hoping it wouldn't be the knock sensors. It is a GE block so there is only one sensor and two plugs. Is there a way I can bypass it with a resistor to "trick" it into thinking it's ok.

nope just do a rewire it's really not that hard
all code 52 means it's there is a problem in the wiring/sensor is bad/or it's the ecu
rewire the right way and it'll meet come back on

 

[BryanDyer]

I have changed the TPS 3 times to see and they all have the same problem the don't connect right. Where could I find test points to see if it is a wiring issue?

you can't just buy a tps and put it on you have to calibrate it

 

[mcammarn]

Your problem is the Lexus AFM and no 550's with the three inch piping and a big filter to add to the problem.

This and you problaly should get 3 in turbo back.

 

[BryanDyer]

This and you problaly should get 3 in turbo back.

no
it's code 52 and the tps

 

[BryanDyer]

the lexus afm will only make him run lean
so you're basically saying his car will run good with 550s even though he's got 4 engine codes in which will cause his problem lol

 

[3p141592654]

None of those codes cause fuel cut. If it is truly hitting fuel cut at 3000rpm, then he should be seeing a code 31 for a bad AFM. I'd recheck the codes to make sure.

TPS won't cause this, nor codes 22 and 43. With those codes this car must be a pain to start when cold though. Code 52 won't cause drivability problems either, just low performance.

I have NFI what this means though....

If I don't try to push though it takes off as if it is floored

.
::shrug::

 

[BryanDyer]

ok well explain to me how my car did the EXACT same thing when I had both those codes
recalibrated tps fixed jerking problem at between 2-3000 rpm AND rewired knock sensors and bam now it boosted fine

 

[3p141592654]

Read his post.

I'm hitting fuel cut on my car. It is jumpy then cuts off whenever I put my foot down more than 1/4 way or go over 3000 rpm's.

Fuel cut, not just jumpyness. Not possible from TPS.

 

[BryanDyer]

Read his post.

Fuel cut, not just jumpyness. Not possible from TPS.

he probably misunderstood what fuel cut is