3800rpm hesitation grounds....
07-27-06, 02:57 PM
#26
Originally Posted by 88rxn/a
maybe ill invest in some since they infact are pretty old..couldnt hurt i guess..arent they pretty cheap at a local shop?
AKA NAPA or autizone? desno plugs correct?
preventive maintenance
AKA NAPA or autizone? desno plugs correct?
preventive maintenance
You can get the denso rebuild kits (o rings, filter, and the plastic cap) for the injectors about anywhere. I used Bosch injector clips. THey did not fit directly on cause the tit is centered on the clip, and off centered on my ijectors. I just shaved the tit off the injectors. They add not extra clamping. I also used shrink wrap to seal the rear of the Bosch clips. You will see what I mean. Instead of electrical tape, the cheap stuff, I used the more expensive silicone wrap for the wires. Soldier everything you can. ANyhow, hope that helps.
07-28-06, 10:09 AM
#31
Originally Posted by The Wankler
I thought it to be pretty common to have a lean spot there. Yes, I have that lean but only when feathering it up around 3400-3600 rpm. If I romp on it, you do not feel it.
07-28-06, 04:13 PM
#34
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Originally Posted by The Wankler
I thought it to be pretty common to have a lean spot there. Yes, I have that lean but only when feathering it up around 3400-3600 rpm. If I romp on it, you do not feel it.
it seams like your slight problem, think they are related?...
07-28-06, 05:20 PM
#36
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Originally Posted by The Wankler
well, on the t2 S4 thje secondaries come on around 3450 or so. That is where my problem is.
What did you do to get rid of the hesitation?
What did you do to get rid of the hesitation?
i cleaned up some of the connections for the grounds under the trailing coils and the one on the firewall, they were clean but it was for good measure....
i took the car out, drove it around a few blocks, bit my tongue and pinned it and screamed "******* RIGHTS" when it ran properly....
i get a slight hesitation when i'm light on the throttle or even 1/2 on it at exactly 4200rpm, it's weird....
but if i romp on it, it's not there, i just feel the secondaries come on ( i believe ) and the car is gone....
when your cruzing and you pin it, do you feel a little blip?, i was told this is the secondaries comming on, is this true?...
i have 720cc's for secondaries....
07-28-06, 05:55 PM
#38
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Originally Posted by The Wankler
I do get a little blip when the secondaries come on. But not at that rpm. What aftermarket cpu are you using to control the 720's?
it was rough tuned, and only tuned for higher end....
at light throttle or medium throttle, i'll get a hesitation when the secondaries are supposed to come on ( 3600rpm approx ) and at 4200rpm, but at WOT they are none existent, i only feel the secondaries come on, thats it....
07-28-06, 07:52 PM
#39
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If you have mismatched primary and secondaries you'll always get a hesitation when the secondaries come on, even with a fuel controller. It's caused by the change in AFR at that point. Even a well-tuned fuel controller isn't sophisticated enough to get a smooth transition. If you have stock injectors or matching upgraded injectors you should feel nothing at the transition.
07-28-06, 08:47 PM
#40
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Originally Posted by NZConvertible
If you have mismatched primary and secondaries you'll always get a hesitation when the secondaries come on, even with a fuel controller. It's caused by the change in AFR at that point. Even a well-tuned fuel controller isn't sophisticated enough to get a smooth transition. If you have stock injectors or matching upgraded injectors you should feel nothing at the transition.
07-29-06, 02:35 AM
#42
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yeah, i'm sure with a good tune it wont be that bad....
it feels harsh when the injectors kick on, but thats the only time it hesitates....
and a slight one once in a while at 4200rpm for some stupid reason....
it feels harsh when the injectors kick on, but thats the only time it hesitates....
and a slight one once in a while at 4200rpm for some stupid reason....
07-29-06, 02:39 PM
#43
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i'd like to also note, you can feel the hesitation revving in neutral, aswell as driving through the power band no matter how hard on the throttle you are....
any idea's?...
any idea's?...
07-29-06, 04:34 PM
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Originally Posted by NZConvertible
As I said above, the EFI system is grounded to the engine block. The block is then connected directly to the battery.
You're correct that most of the sensors are grounded to that point, but the O2 sensor is not one of them. Its ground path is through the exhaust, which is bolted to the engine, which is connected to the battery.
You're correct that most of the sensors are grounded to that point, but the O2 sensor is not one of them. Its ground path is through the exhaust, which is bolted to the engine, which is connected to the battery.
The ground wires from the battery to the body and engine are meant to carry large amounts of current. The Emission Ground (page 50:10 & 50:16 in the 86 manual) is used as the reference for the 5 volt sensor circuit (and also for the ground shield wire on the oxygen sensor although I've never actually seen that shield) and it would fry the ECU if any large amount of current ever tried to go through that ground.
It's interesting to see that the harness ground on the top of the engine brings the engine ground reference to the ECU and the ground in the boost sensor is the ground reference coming out of the ECU going to all the sensors.
By the way, the harness ground on the top of the engine also is directly connected to the fuel pump jumper (not the check connector like I said earlier)
A good solid ground on the 5 volt sensor system and oxygen sensor will guarantee that the ECU knows exactly what is going on in your engine.
Frankly I don't understand how those grounds could cause the 3800 RPM hesitation, but it couldn't hurt...
ed
07-30-06, 04:07 AM
#46
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Originally Posted by TehMonkay
Speaking of grounds, when I took out my tranny, I didnt know there was an extra small ground on top of it, and now I dont know where the plug on the end of the wire is supposed to go. Where does it go?
07-30-06, 08:36 AM
#47
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Originally Posted by Archangels
i'd like to also note, you can feel the hesitation revving in neutral, aswell as driving through the power band no matter how hard on the throttle you are....
any idea's?...
any idea's?...
UNLESS, the boost/pressure sensor has its vacuum line disconnected or there is no source of vacuum to that line. Or the boost/pressure sensor is kaput internally.
THAT hesitation is not seconday injector related if the boost/pressure sensor is working right.
07-30-06, 01:11 PM
#48
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yeah i figured as much, i dont know what the problem with that is....
i'm still wondering if the UIM ground differs from the ground on the rotor housing....
if it does differ, does anyone have information about it and/or pics?...
if it does, i'll be heading to the garage to fix it asap....
i'm still wondering if the UIM ground differs from the ground on the rotor housing....
if it does differ, does anyone have information about it and/or pics?...
if it does, i'll be heading to the garage to fix it asap....
07-30-06, 05:10 PM
#49
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Did i get the UIM Ground done properly?, and in the right place?...
I couldnt reach it unless i took the throttle body and UIM out, so i'm assuming yes....
And there was nothing else i could have grounded that had a clip on it, this one did have a ring connector, and this was the best pic i took....
Any Input?...
07-30-06, 05:46 PM
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* EDIT *
I just took the car for a drive, it still hesitates at 4200rpm, but if i go WOT and start racing through gears it wont hesitate....
i dont get it....
I just took the car for a drive, it still hesitates at 4200rpm, but if i go WOT and start racing through gears it wont hesitate....
i dont get it....