I'm still having two hesitation issues that maybe one or more of you could help me with.

I have the dreaded 3800rpm hesitation, and a 5500-5600rpm hesitation.

both of these can be worked through with the throttle and i can get to redline... i'm not doing it since i saw my wideband data. (i'll get to that in a minute)

1: i regrounded my engine bay. leading & trailing coils, Fuel Injectors, and a line to the ECU.
2: i rewired the fuel pump, and moved the resistor pack & relay to the back of the car. (next to the antenna)
3: i checked the TPS with my multimeter. i get a clean sweep; no jumps or flat spots, and tuned it to 1k ohm at idle and i get about 5.4 - 5.5 at wide open throttle.

I have an idle of about 800 - 850rpm but i'm a little fuzzy on how to set the idle while balancing the Idle adj screw, BAC, and TPS to make everything work properly... i'm running 3'' RB out the back, a custom TID still with the S4 AFM...

my LM-1 wideband sees about 13.5afr at idle about 14 between 1200 and 3600 then i get a spike when the car hesitates at about 3800rpm to ~16afr then it's back to about 12afr until 5500rpm when it spikes to 20.4afr... so... SUPER LEAN!!!! and that's bad!!! then it drops back down to 11-12afr and above 7000rpm the afr drops to ~9

please. if you can help me out i would appreciate it. I'll upload a screenshot of my wideband data from one of my pulls under load if it will help.

thank you all for your time and your help.

 

What is your injector setup? 720 secondarys? Switch to lower ohm resistors (try 10 watt 6 ohm) or buy an FJO injector driver.

The other option is to get an Rtek 1.7/2.1 , as they have fixed bugs in the factory injector staging code. You may have the best luck with this.

 

i'm still running the stock 550's. i've made sure to have them cleaned by witchhunter perf, so i'm pretty sure the flow rate is fine. stock turbo, stock boost, ported wastegate with a landrover exhaust valve for the flapper.

since it richens up again at high rpm i don't think i need to put the 720's on it yet.

I am looking into the Rtek or a megasquirt, but i have yet to do enough research on them to make an educated decision.

here is the image of my LM-1 data.

 

what do your plugs look like...show me a pic i wanna see them.

 

never mind. i didnt even read the whole thing...

 

contact digitaltuning (the guys who make the Rtek) and ask them if their Rtek 1.5 (basic chip for a car with 550/550) has the new injector staging bugfix. I know the 1.7 (550/720)and other models do.

 

by idle adjust screw do you mean the one that actually moves the throttle plates? you're not really supposed to touch that one, it changes when the secondary throttle starts opening, so the ecu can get confused (cause it doesnt know)

you should be able get it to idle with just the tps, and idle mixture.

the 3800 spike sounds like it might be a staging issue, no idea on the 5500 problem.

you might wanna go for a drive with a volt meter on the afm, and see if its got any dead spots.

id also check for dumb things, the vacuum diagram isnt very clear in any book, ive traced em all down before, a crossed one will do strange things. also people love to plug the fuel pressure regulator into a nipple that DOESNT see boost so it runs lean in boost.

 

ok. heres an update. i backed off the throttle stop screw and readjusted all the idle components, per the FSM.

i reset the TPS to 1k ohm at idle, the variable resistor to the highest idle, adjusted the BAC to get my idle at a rock solid 750rpm.

i brought my SAFC back to zero modification, and my hesitations are still there... kinda.

attached are links to two videos. one outside, one inside. i appologise in advance for the delay of the first vid. i'm not near my mac, so i didn't edit out 'me walking to my car and starting it.' needless to say, i have no cats and a BOV thus the smoke on decel.
http://www.youtube.com/watch?v=ze0Um8zUGuQ
http://www.youtube.com/watch?v=3I4OnFUKAv8&feature=user

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<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/3I4OnFUKAv8"> </param> <embed src="http://www.youtube.com/v/3I4OnFUKAv8" type="application/x-shockwave-flash" width="425" height="350"> </embed> </object>

 

Previously dealing with hesitation issues myself, I found that the ECU is looking for 1V from the TPS at idle. Whether or not that's produced by setting the resistance at 1K ohms or not is the question. I ended up going to about 1250 ohms before I got a full volt. Helped most of my issues on the NA. Try backprobing for voltage and recheck, you might have aimed a little low.

 

hank,
are you testing the voltage coming from the TPS at the engine bay plug or down at the ECU? if you're testing the ECU, how small are your probes to get into the back of the middle plug? and where are you pulling your ground signal? the ECU wire or the chassis?

thank you for our help.

 

Test at the engine, ground to wherever. One wire will be input, one ground, one output. You should have 5v in, and 1v out at idle -when warm-, ideally with the engine running.