25-3500 hesitation under partial throttle
#1
25-3500 hesitation under partial throttle
Car: 84 FB w/ TII swap, 720 injectors all around, SDS management + MSD igniton.
Problem: When under partial throttle, in any gear, engine seems to lose power if the throttle is held steady at 20-30%, if I increase throttle, the engine will suddenly surge up to the normal level, go into boost, all that good stuff. AFR gauge doesn't show any leaning out nor does the fuel pressure gauge change from normal readings for the throttle position.
now, if I just accelerate hard (70%+ throttle) there's no pause, no hesitation, no power loss. Also, the problem seems to lessen, but never fully goes away after I've been driving for a bit (15 min or so).
I've tried dicking with the fuel/RPM settings in the SDS to see if they're too low, but nothing's changed other than the AFR reads rich, which it should.
Plugs don't look bad, fuel filter was recently changed (9 months ago). What should I be looking for?
Problem: When under partial throttle, in any gear, engine seems to lose power if the throttle is held steady at 20-30%, if I increase throttle, the engine will suddenly surge up to the normal level, go into boost, all that good stuff. AFR gauge doesn't show any leaning out nor does the fuel pressure gauge change from normal readings for the throttle position.
now, if I just accelerate hard (70%+ throttle) there's no pause, no hesitation, no power loss. Also, the problem seems to lessen, but never fully goes away after I've been driving for a bit (15 min or so).
I've tried dicking with the fuel/RPM settings in the SDS to see if they're too low, but nothing's changed other than the AFR reads rich, which it should.
Plugs don't look bad, fuel filter was recently changed (9 months ago). What should I be looking for?
#3
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Not sure if it helps but on the second gens we get a dreadful hesitation around 3.5-4k rpm because of bad ground contacts. Check your grounds to engine/battery/car. Clean all other connections under the hood.
Also you might want to look at the tps, as you say it doesn't hesitate if you just gun it through that range right?
Also you might want to look at the tps, as you say it doesn't hesitate if you just gun it through that range right?
#4
rotorhead
iTrader: (3)
what you are describing may be the 0psi hesitation. I had it on stock ECU. That is not normally correctable just by fixing grounds. The Rtek 1.7/1.8 and 2.1 have different injector staging code to correct this. They call it the "stumble elimination fix"
http://www.digitaltuning.com/index.p...4T2#stumblefix
http://www.digitaltuning.com/index.p...4T2#stumblefix
#6
Not sure if it helps but on the second gens we get a dreadful hesitation around 3.5-4k rpm because of bad ground contacts. Check your grounds to engine/battery/car. Clean all other connections under the hood.
Also you might want to look at the tps, as you say it doesn't hesitate if you just gun it through that range right?
Also you might want to look at the tps, as you say it doesn't hesitate if you just gun it through that range right?
what you are describing may be the 0psi hesitation. I had it on stock ECU. That is not normally correctable just by fixing grounds. The Rtek 1.7/1.8 and 2.1 have different injector staging code to correct this. They call it the "stumble elimination fix"
http://www.digitaltuning.com/index.p...4T2#stumblefix
http://www.digitaltuning.com/index.p...4T2#stumblefix
#7
Wankel
iTrader: (1)
I saw a thread, the one I'm looking for... They said to check all grounds, and the solder joints in the ecu. If you don't know how to solder go to a tv repair shop they know electronic stuff. or you could get a magnifier, and check them out. Worked great for my clock! I Believe one of the main grounds is next to the egr hard as **** to find. That's why I am looking for that thread in the first place. I have the same problem, But I am a tv repair man, and good with cars. I'll keep you posted.
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3500, 91, accelerate, ecu, hesitating, hesitation, infiniti, loses, lsvtec, megasquirt, power, q45, rpm, shop, solder, throttle, tv