My buddy has a 94 Camero Z28 that doesn't downshift back into first when coming to a stop. The automatic tranny was just rebuilt, so he took it back and they said nothing was wrong with the tranny. They ran it on the computer and it said the mass air flow sensor was going. He is also getting Check Engine light. Could this be the reason why the tranny won't shift back down?
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1984 Mustang GT Hatchback
Stock 80' 302
Comp Cam XE262H
Ported E7 heads
Summit long tubes
Weiand Stealth Intake
Holley 600cfm
Duraspark Ignition with GM HEI module -
He needs to get is scanned and see what the code is. I know the trans place says it's the MAF. but I don't see how that would effect the transmission. There are a bunch of things that the ECM monitors with the trans. It can tell you a lot of things. It sounds like it might have a bad electronic solenoid.2002 Electron Blue Vette, 1SC, FE3/Z51, G92 3.15 gears, 308.9 RWHP 321.7 RWTQ (before any mods), SLP headers, Z06 exhaust, MSD Ignition Wires, AC Delco Iridium Spark Plugs, 160 t-stat, lots of ECM tuning
1995 Z28, many mods, SOLD
A proud member of the "F-Body Dirty Dozen" -
Sounds like a trans problem to me. The PCM uses MPH and TPS to calculate up/down shift points. I don't see where the MAF is involved. You might want to reset the PCM to clear the code. Maybe it was an old one.Rob B 95Z A4 Tech Page (Part numbers / locations, how to's, schematics, DTC's...) Home Page - shbox.comComment
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I seriously doubt it's his MAFS, it's definitely gotta do with his tranny.Hercules
2008 Sunburst Metallic HHR LTComment
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Which tranny is it..? 4L60 "700R4" or the 4L60E..?
The 93's and early 94's have the 700R4 which has a detent cable to down shift the tranny... If it does have the detent cable, that may be the problem, it may need to be adjusted.
If it is the 4L60E, it very well could be a shift solenoid "they can get damaged from removal."
Regardless which tranny he has, both problem solutions are a common result of a tranny R&R...John Wagner "Owner"
D.E. Engine Performance & Fabrication
1995 FormulaComment
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If it is a 94 as stated (and stock), it will be a 4L60E.Rob B 95Z A4 Tech Page (Part numbers / locations, how to's, schematics, DTC's...) Home Page - shbox.comComment
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Yes, it is the stock tranny and I forgot to mention he had a shift kit installed when it was rebuilt. It sounds to me like that detent cable needs to be adjusted. Are these hard to adjust yourself or should he take it back to the repair shop?1984 Mustang GT Hatchback
Stock 80' 302
Comp Cam XE262H
Ported E7 heads
Summit long tubes
Weiand Stealth Intake
Holley 600cfm
Duraspark Ignition with GM HEI moduleComment
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A 4L60E has no detent cable. It's electronically controlled (hence the E in the designation).Originally posted by foxxed84Rob B 95Z A4 Tech Page (Part numbers / locations, how to's, schematics, DTC's...) Home Page - shbox.comComment
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Does it have a dentent cable?
Some early 94's did have the 4L60 "700R4." But, since the car does have a MAF sensor, I think you may have the 4L60E, but I'm not sure...
But, I do know for a fact; some 94's had the 700R4...John Wagner "Owner"
D.E. Engine Performance & Fabrication
1995 FormulaComment
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That's the first time I've heard thatOriginally posted by DarkEnhancement
94 Black T/A GT, Advanced Induction 355, 3200 stall, built 4L60E, Moser 9", Baer Brakes, Shooting for 11s...Comment
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In the 7 years I have been following the 4th gen f-body, this is the first time I have seen anyone post that.Originally posted by DarkEnhancementRob B 95Z A4 Tech Page (Part numbers / locations, how to's, schematics, DTC's...) Home Page - shbox.comComment
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Originally posted by DarkEnhancement
Don't think so........ then again, the 89 Turbo TA had a twin turbo 350.
Seriously, there's nothing from the factory that states that a 700R4 was used off the assembly line. Never seen one, never heard of one so this is unique. The 4L60 is almost the identical transmission, the 4L60E being the electronic controlled version.
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This tranny, in the f-body, is an "E".....Originally posted by foxxed84
So, I am taking it that the tranny will shift down if you manually shift it into first? I would think that it is probably an elec. issue, but not necessarily a shift solenoid...it could be a pressure control issue. Is this the ONLY problem youre having? Does it upshift late? It could be a hanging valve in the valve body....sometimes if the cooler is not flushed after a blown tranny, the metal gets puked into the valve body and wreaks havoc......
Highly doubtful that it is the MAF.....but if it is truly coding for a MAF, you should fix that issue FIRST. Then, after thats fixed bring it to your tranny guy and tell him to fix it.....there are a few different possibilities for no 1-2 downshift.96 WS6 Formula: Ram Air, 383 Stroker, Ported LT4 Heads and Manifold, 1.6 Crane Rollers, 58MM T.B., AS&M Headers, Borla Exhaust, Meziere Elec. H2O Pump, Canton Deep Sump Oil Pan, 100 HP OF TNT N2O!! , T56 Conversion w/ Pro 5.0 shifter, SPEC Stage 3 Clutch, Hotchkiss Subframe Conn., Lakewood Adj. Panhard Bar, Spohn Adj. LCA's, BMR Adj. T.A., Custom 12 bolt w/ 3:73's, Moser Axles, Eaton Posi, Moser Girdle
11.6 @ 123mph (1.6 60' - getting there
)
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Never heard of a 700R4 being put in a 4th Gen F-body from the factory, The 1994 F-body had a 4L60E.
Definitely sounds like a transmission oriented problem. If it were a VSS or TPS sensor problem it would also affect the upshifts. I would probably agree with N20LT4Bird. It is common for trans builders to overlook flushing the stacked plate core and hardlines. If just a bit of trash gets into the valvebody it can cause problems.Comment
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It is common for BAD tranny builders......Originally posted by fastTA
96 WS6 Formula: Ram Air, 383 Stroker, Ported LT4 Heads and Manifold, 1.6 Crane Rollers, 58MM T.B., AS&M Headers, Borla Exhaust, Meziere Elec. H2O Pump, Canton Deep Sump Oil Pan, 100 HP OF TNT N2O!! , T56 Conversion w/ Pro 5.0 shifter, SPEC Stage 3 Clutch, Hotchkiss Subframe Conn., Lakewood Adj. Panhard Bar, Spohn Adj. LCA's, BMR Adj. T.A., Custom 12 bolt w/ 3:73's, Moser Axles, Eaton Posi, Moser Girdle
11.6 @ 123mph (1.6 60' - getting there )
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