Once mine heated up to 213 or so, I had problems as well. My car runs fine when cold. Once it warms up like you describe, it goes bad on me. I have a EFAn and was using a radiator probe for my temp signal to the fan. On at 180, off at 165. However, the engine temp would reach 213 before it went on. So, I went and bought a Screw in probe and a Adjustable relay. I hope the heat has to do with it.

Note: When I ran a new wire for my O2 sensor, the driving got better. Might be worth a shot.

 

[QUOTE=boost_its_what_for_dinner;7196228]see where you say it happens at 2800 mine is not steady its any time vacuum 2-3k, it almost seems like when the motor is under a load in vacuum like 16-5 inhg it wants to go lean... so maybe i need to data log my load index and add fuel..???88888888888888888888888888888888888888888 88888888888888888888888888888888888888888888888888 888888888888888888888888888888888888888

I would (add fuel at that rpm/load). This is not the hesitation at the secondary transition point. I say that to let you know I know that.

My guess is that at the rpm your noticing this hesitation, that the fuel in that area is too lean and you need to add fuel at that rpm range.

I mentioned something earlier that I think is relevant. If you go into closed loop and the afr was at say 13afr prior to going into closed loop, you won't feel any hesitation as the afr is pulled up to 14.7 by the ECU.

BUT if the fuel was LEAN prior to going into closed loop (like 16-17afr), you WILL feel a slight hesitation when the ECU goes into closed loop and pulls the fuel DOWNwards (down to 14.7). It's an annoying hesitiation of small magnitude compared to the hesitation found at the secondary fuel injector transition point.

When going to closed loop, the ECU is trying to maintain something like a 14.7 whatever afr. When PULLIING the afr up from say 13afr to 14.7, it is not noticable. BUT when pulling the afr down from say 16-17 afr TO 14.7, it IS noticable and annoying.

The remedy is to rid yourself of afr that are over 15afr or so, give or take. Just my thoughts on that.

 

Okay so I went back today and looked at the grounding issure at the ECU you know how I said before it didnt work well I noticed that I messed up and had some wires switched around and such . So I fixed the problem there and it did seem to help a bit but instead of the car just hesitating its like it cant make up its mind . kick in kick out kick in kick out and its just jolting down the street you know lol . My idle is currently set at 750 and the tps is adjusted to one bulb coming on I have a K&N air intake on it can that mess with the air fuel mixture and can it be causing the problem with the jolting around should I up my idle a bit and adjust AFR ?

Also my ports do open I have tested to see if the actuators on the side pump they do but I am suspicious that the hole's in my rear cat are causing the ports not to open up all the way or part of the time because of a huge lack of back pressure and I read it relies on that pressure to kick in past 3800 I am already planing on a RB presilencer and replacment pipe combo I am hoping maybe that will fix it ?

 

thx hailers ill try that out, but its happens most in 4th gear at 2k-2700 now... ill get back to yall.

 

I understand. I'm just wanting to seperate this type of hesitation from the traditional secondary injectors coming on line type of hesitation.

I had a SAFC prior to the RTEK2.0, and had your type of hesitation and came to the realization that it was caused by a tool lean conditon. This is just a hunch, guess, WAG and the problem might be another thing all together.

 

Was looking @ the FSM. 2C is also a ground. Should I do this one as well? Is there a reason you did not use 2C?

 

No. Do 2C also. Bad memory here. This is a possible fix for hesitation/stuimble at the 3800 rpm range under load when the secondary injectors come online. Hesitation at some other rpm range is probably another thing.

This has worked for several people over the last few years. Then it has not worked for some others. Why? got me

There is the simpler way of doing these wires other than attaching an extra wire to each of the wires listed. You can simply follow the wires up the harness about a half foot and find where they all come together, then attach/solder a new wire at that point and gnd the other end of your new wire using a ring terminal.

IF you've tried other approaches in the past to fix 3800 rpm hesitation, then take the few minutes to try this as a fix. Nothing to lose other than a hour or so in time.

 

I recently add fuel right at 3800 on my SAFC to around +10 and minimized the hesitation.

The four ground wires I added to the ECU, I have bolted to the 2 bolts holding the ECU to the tray a the bottom, I don't know if that is a good enough ground so I tihnk I will add a ground from the chassis to the tray and see if that works.

 

so i added fuel (5%) for the first 2 rpm settings from load of 2-14 i think it got worse.. driving down the interstate in fourth and fifth gears it will be rich and running fine but then out of the blue it will go flat lean on me for no reason( and no big change in the throttle).
also what % is the tps supposed to read when car is off. mine says 21% at idle and off. this is a shot ion the dark but could the throttle body be out of wack.. the screw that adjust the tps, could it be not set right ?

 

^^^^^ Have you solved you heating issues?

 

Hailers , When you say all the ground wires come together half a foot up the harness do you mean they are all crimped at that point ?

 

I believe they are. Here is an EXAMPLE of a crimp. This isn't the ground crimp for the ECU grounds.

 

cool ill check it out I never noticed a point where they all come together before .

 

ya it runs around 176-198
my fan was wired up backwards... because the fan blade had been pulled out and flipped around by a friend and i forgot this while we were putting my new motor in and getting everything hooked up. so its fine now(cooling wise)

 

my ecu is regrounded on pins 3A, 3G, 2R, and 2C, but i still have the staging hesitation. also have cleaned the grounds under the UIM and at the LH strut tower

 

I just did the regrounding yesturday. Haven't driven it yet. I did notice that pin 2C is brown. It your 2C brown?

 

i dont remember, the previous owner did most of the grounding work

but i was a little confused.. in the FSM, it shows the ecu pinouts on page 4B-33, and it says the diagrams are "control unit side." i would think this means you unplug the connector and look at it from the ecu side. however, if you look at the wire colors and compare to the Haynes manual pinouts, the diagrams seem to be from the wire-side of the connector

all my injector splicing/grounding/etc matches the haynes manual

 

I am pretty sure its based off of the wire side thats the way I did it , was fixed for two days then went back to crud again . And 2C is a ground wire even though its brown with a black stripe . I did all the extra grounding like you did above and I had no real change either I've done all the regrounding actually everywhere and no change . I think maybe the connectors to my secondaries are not connecting good enough the plastic is kinda broke and they have no clips like the primaries do plus I have a cracked lower intake manifold gasket so when I rev under the hood I hear like a click or pop sound ?

 

Umm this sucks I tested for continuity on my secondary wires and 3H gets gets it but 3F dont show at all so . The freakin wire is broken or fried somwhere in the harness what can I do ?

 

something odd..i didnt drive my car all day thursday and when i did drive it yesterday it ran f***ing great and then the longer i drove the worse it ran... so i think my sock on the fuel pump is clogged again...

 

Okay somthing new i havent heard of yet but its happening . It wasn't my 3F wire but the brown yellow stripe resistor wire to the rear injector not getting continuity . The resistor that wire runs two is blown the other three resistors work fine but nothing on the one the brown yellow runs two . Would this cause hes or stuttering . And where could I find a new one online Google turns up nothing for me ?

 

alright i dont have the secondary hesitation. i had fuel pump issues. but i have a lean problem still happens most in 4th gear at 2k-2700 now...cruiseing throttle.