O2 swing amount and OD shudder
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O2 swing amount and OD shudder
Been using ThirdGen for lots of technical advice. Thanks to all....
I'm working on a 400 chev with Dart heads, 10:1, and a .454/.480 216/234@.050 cam in an '81 Suburban. I know.... the combo isn't ideal for TPI but it worked great at high altitude with a carb, not so well where I live now (2200 MSL). I've put in a TPI from an 88 Formula 5.7 (165 and cold start delete) and am using the ARAP bin. I've been pretty successful so far in getting everything squared away but have a few questions.
I'm using a HALMETER AF30 30 segment O2 sensor in the header collector, next to the stock one, and I'm wondering how much the O2 volts should swing. Is it correct to assume that the closer to 128 the BLMs (and INT also) are, the swing will be minimal?
The trans is a TH700 (RV converter with stock stall) that I had a hydraulic TCC lockup installed in that shifts according to engine RPM. The lockup occurs late in 3rd about 2000 rpm and then the trans shifts into OD with the clutch engaged. At the shift into OD at about 1700 rpm, the vehicle shudders terribly and continues unless I feather the throttle and there's no load. If I wait to manually shift into OD until 2200 rpm (about where the motor starts to come on) the shudder doesn't happen. My carbed setup didn't behave like this. Any ideas on how to prevent this? I thought I'd read about this occurring and that it was tough on TC clutches so I'd like to minimize it.
When doing the IAC reset, the IAC is driven all the way open (160 steps), right?
Thanks - Dan
I'm working on a 400 chev with Dart heads, 10:1, and a .454/.480 216/234@.050 cam in an '81 Suburban. I know.... the combo isn't ideal for TPI but it worked great at high altitude with a carb, not so well where I live now (2200 MSL). I've put in a TPI from an 88 Formula 5.7 (165 and cold start delete) and am using the ARAP bin. I've been pretty successful so far in getting everything squared away but have a few questions.
I'm using a HALMETER AF30 30 segment O2 sensor in the header collector, next to the stock one, and I'm wondering how much the O2 volts should swing. Is it correct to assume that the closer to 128 the BLMs (and INT also) are, the swing will be minimal?
The trans is a TH700 (RV converter with stock stall) that I had a hydraulic TCC lockup installed in that shifts according to engine RPM. The lockup occurs late in 3rd about 2000 rpm and then the trans shifts into OD with the clutch engaged. At the shift into OD at about 1700 rpm, the vehicle shudders terribly and continues unless I feather the throttle and there's no load. If I wait to manually shift into OD until 2200 rpm (about where the motor starts to come on) the shudder doesn't happen. My carbed setup didn't behave like this. Any ideas on how to prevent this? I thought I'd read about this occurring and that it was tough on TC clutches so I'd like to minimize it.
When doing the IAC reset, the IAC is driven all the way open (160 steps), right?
Thanks - Dan
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Joined: Jun 2002
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From: great lakes
o2 swings can vary i usually look for an average of 350-750 or so. anymore than that and the int starts to move then the blm cell changes.
as for your shutter. its most definately the TCC. there is a pressure switch in the tranny the the ecm uses to turn the TCC on and off. i dont think the hydolic lookup is a good scheme. the TCC was never meant to deal with this. what you really have is a shutter. they only fix i can think of is to chage teh goverenor srpings to reflect a higher shift point or use the TCC controls in the 165 ecm to run the show.there is a good chance however that the converter is trash. using a cheap clutch and very porr machine work.
if your willing to try the chemical warfare approach there an aditive thats used quiet a bit by tranny shops to elminate TCC shudder. stop by an AMMCO and see if they would part with a bottle.
as for your shutter. its most definately the TCC. there is a pressure switch in the tranny the the ecm uses to turn the TCC on and off. i dont think the hydolic lookup is a good scheme. the TCC was never meant to deal with this. what you really have is a shutter. they only fix i can think of is to chage teh goverenor srpings to reflect a higher shift point or use the TCC controls in the 165 ecm to run the show.there is a good chance however that the converter is trash. using a cheap clutch and very porr machine work.
if your willing to try the chemical warfare approach there an aditive thats used quiet a bit by tranny shops to elminate TCC shudder. stop by an AMMCO and see if they would part with a bottle.
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