SidewaysFC

ok, my mechanic couldn't figure out ...maybe not enough performance experience, idk.

installed my fmic setup a few weeks ago and drove it around for a while with no problems. a couple nights after, i boosted hard and popped an IC hose as well as flooded the car pretty good. it drove home fine after i tightened everything back up and unflooded her. now the car has a cold idle problem and hesitates on the low end. after 4500rpms or so the car pulls smoothly to redline like it normally would though. any thoughts?

i want to say dirty primaries? ...too much premix? ...something fuel related?

maybe a bad thermoswitch for the cold idle? the warm idle is rock solid at 800 rpms.

prjct87rx7

iTrader: (7)

maybe your leading coil is bad? if it runs fine after 4500 when the trailing coil kicks in?

SidewaysFC

nah. trailing and leading coils fire on the whole rpm range.

iceblue

Have you checked all the grounds? The on the rear rotor housing under the UIM? The one on the tranny mount to firewall? Your RPM range is very close to where the electrical grounds will make the car bogish.

Have you checked your TPS?


prjct87rx7 - The L and T as stated fire all the time. Factory timing runs a 0 split at L-5ATDC and T-20ATDC. I Think maybe are you confusing the 3.8krpm 6pt on the N/A? Or the secondary injectors at 3.8krpm?

SidewaysFC

TPS was reset by mechanic as well as he tightened down the excessive grounds everywhere.

coolcars44

iTrader: (5)

well i think you need to have the fuel pressure checked usually unless you have replaced the fuel filter already and put a new race pump in your car you will have fuel pressure problems.if your modified you need like a good 85-95 psi of fuel pressure past the fuel filter

SidewaysFC

fuel filter is recent maybe 6,000 miles ...no more than 10,000 miles. It has a walbro, condition and mileage are unknown ...hasn't been a problem before but I suppose checking the voltage to the pump would be a good idea.

mr_vaughn

iTrader: (1)

i have a hesitation with my FMIC too.

here are my variables.

3200 -4200 rpm
20 -70 % throttle
0 - 7psi boost
as boost builds the car start to buck more and more..
but if you go WOT and build boost to max the system it does not happen.

My suspition is the AFM. i want to move it after the turbo either before the IC or after if i have space. to decrease the distance the air has to travel to the engine.

i am going to replace my secondaries with 850cc and tune on my e-manage too see if that helps 1st.

SidewaysFC

sounds like what's wrong with my car too.

the worst point seems to be the transition between vacuum and boost or 0 boost. while the turbo is building boost the car will buck until i get to about full boost ...but it will still do it if i try to go 100% throttle while boost is building to max.

the afms were switched out so that rules out that condition unless both have the same errors.

im telling you it has to do with the ecu or fuel maps ...not that they have changed for some random reason, but that due to reduced temps from the fmic's compared to stock tmic's as well as my (4) 620 cc injectors and walbro and premixing and no fuel control. i think i want to advance the timing some to see if that has any effect. that way i may be able to consider if im just bogging cause the car is pig rich until full boost ...which would make perfect sense

tomm

When I bought my tII the factory boost guage was broken. The car was bucking about 4,000 rpms. I put an aftermarket boost guage on and found that the car was bucking between 7 and 8 psi but would smooth out once I got past 8 psi. What I found out was that the fuel cut connection was seperated.
If you guys have done any exhaust modifications or anything else that would allow the car to boost above 7 but dont have a fuel cut defenders your factory fuel cut system may be kicking in causing the bucking.

SureShot

It's probably the TPS.

It can be perfect at idle, but have a worn spot at part throttle.
Clip on a cheap analog (needle type) meter & check the sweep as you open the throttle.
Look for a jerky spot in the needle sweep.

The ECU sees bad spots as idle signals & gives fuel cuts.

SidewaysFC

The TPS was reset. But your saying I need to get a analog multimeter and attach it to the tps connector and have someone rev the engine while I watch the meter for any erratic spikes?

How about fuel injector cleaner or MMO to clean the fuel system as a just-in-case measure? or create a vacuum leak and rev the motor on load to see if that cleans up the bucking? ...i'm pretty sure if the car revs better on a vac leak, it will tell me i have too much fuel.

mr_vaughn

iTrader: (1)

I have the Racing Beat Fuel cut controller and have never removed it

i will try removing it to see what happens.

coldfire

iTrader: (1)

well the engine doesn't have to be on when you are testing the TPS. either get somebody to push the pedal down from zero to full, or you can just turn the throttle plate lever on the TB with your hand.