Max_5gen

iTrader: (2)

I don't know how to describe this to make any sense but I'll try my best:
93 SE auto:
1. When driving uphill on the hwy car seems to disengage intermittently for a fraction of the second (loses power I'd say). When I turn OD OFF the effect is much more prononced - it kind of stops pulling, that's why going uphill is important.

2. When downshifting due to WOT car doesn't want to stay at lower gear and switches back too soon bogging down the engine. It does go to 4k+ rpm for a few seconds. It seems I can keep it downshifted if I keep pedal on the floor but this wasn't neccessary before.

3. Effect seems to be engine temperature dependent and doesn't happen on cold engine.

I cleaned CTS connector, injector connectors, MAF connector, camshaft sensor connector, battery posts, ground. Car used to have error code 13 either due to problem with CTS contacts or just because I forgot to clear it last time. After replacing CTS connector altogether the problem became less severe but it is still there. Before replacement I couldn't keep driving in the left lane on the hwy as I couldn't control speed of the car anymore - it was unexpectedly slowing down then coming back all on its own. Now I can at least drive it. CTS was bought approx 1 year ago new at the dealership.

My next idea is to replace MAF to see if it will make a difference but your input is greately appreciated.

James92SE

iTrader: (31)

Number 1 certainly sounds like the transmission is slipping

LvR

Manually selecting 1st or 2nd ............. does the box stay engaged (both accelerating and decelerating) and do you get decent revs out of the engine?

CapedCadaver

iTrader: (8)

only if the revs spike tho. if it just has little flashes of no-acceleration and the rpm dips 100RPM or so, then it's an air/fuel/spark issue. mine was doing that alot a few weeks ago.

Max_5gen

iTrader: (2)

That's tricky part - I experience this only on hwy doing 100+ km/h. Doing so in 2nd will get it too high in rpms I think. 'I think' I got the rpms jumping around when I put it in 'N' at that speed. I tried to be steady on accelerator as much as I can since without load rpms will jump on their own with slight pedal movement. It is hard to do this on hwy so this is why I'm not yet sure.

It did it once about a year ago up to the point I had to go off the hwy. I turned back home, removed air box and sprayed AT connectors with Deoxit. I also did it to sensor connectors and it did help, not sure which one as I was in rush. It seems it came back. This time around I have AT resistor connector left and those tranny connectors, the rest I already cleaned/replaced.

I also have one candidate for a bad injector - the rear middle cylinder quit working few times and this is not spark plug/coil as I swapped them with another cylinder and problem remained in the middle. Well, I have some time now, will keep checking.

LvR

So iso trying to figure one problem you actually have at least 3 known ones? ............... you are not going to get very far here I am afraid.

Sort this and the injector first - that motor's ECU must at all times be able to maintain a rock steady speed irrespective of engine load ............... if it cant you are wasting your time troubleshooting anything else

Then come back and answer my original question - does the box allow you to select 1st or 2nd manually and to use all the revs of the motor while both accelerating and decelerating with no problems? (don't get on the highway - its not a speed test - drive around the block when the box is warm)

Max_5gen

iTrader: (2)

You're probably right, it's just I didn't see that injector off lately that's why I kind of forgot about it at first. Winter is coming though and injectors ain't getting better on their own so I better replace it anyway especially having 3 working ones sitting on a rail from the previous engine. When the cylinder was off it was always on cold engine right after start. It didn't last too long - aboute 1 minute tops, I actually missed the opportunity to pull the ignition sockets off few times when it wasn't working as it was too short. OTOH I'm breaking my own rule here - fix what you know first then see what happens. I did confirm it wasn't spark plug/coil so the most probable thing left is injector I think.

I'll do that 1st - 2nd test regardless too as it is an easy thing. Thanks for trying to help.

Max_5gen

iTrader: (2)

OK, I went for a test drive:
going in 1st I can get it up to 3.5k rpm then it shifts to 2nd despite the shifter being in 1st.
going in 2nd I can get it all the way to red line and it doesn't jerk as it does in 'D' or at least I couldn't feel it.

I couldn't see a difference between shifter positions 1 and 2: it starts in 1 goes up to 3.5 k rpm and then shifts to 2nd. Going in 2nd and putting shifter to 1st doesn't make any difference, car stays in 2nd. Is this normal?

1992maximase30

no i think your shifter is off.
i had the same problem with this i had it in first then it whould shift from 1st to 2nd. also when i though i had it in drive it would sometimes slip form 1st to 2nd. or once i put it in drive it would rev then catch.
once i had adjusted the shift linkage it was all good.
now i can bouce off the rev limiter in first.

LvR

+1

Max_5gen

iTrader: (2)

Thanks, I'll do it tomorrow.

Max_5gen

iTrader: (2)

OK, it was inhibitor switch.

I checked its operation first and noticed that I can't get battery voltage on pin 16 of AT control unit (means position '1') even if I move selector past 1 mark. Took it off, opened and it indeed had bad oxidation on internal contacts. Cleaned, put it back on and all the problems with AT shifting are gone - I can get it wherever I want in 1st, I can downshift going in 2bd, it stopped jerking on hwy, it stays downshifted when I depress accelerator.

Thank you all for pointing me in the right direction.

BTW, who in the right mind called that thing 'inhibitor switch'? It is only one of its functions while the main one seems to tell AT control unit the position of the selector. What was wrong with 'Selector position sensor' or something like that? I also wonder what is it doing on the transaxle - does that lever which drives inhibitor switch switches something inside the transaxle as well? If it doesn't then it would be pretty stupid to put such device so close to the road and so far from the selector itself.

internetautomar

iTrader: (30)

it's commonly called a neutral safety switch also. it is there to prevent the car from starting in gear. at least back in the day that was it's only function. it is on the transaxle so that it gets an accurate reading of what gear the trans is actually in. If it were by the shifter it would be affected by issues such as our bushing failure and be able to start the car with the transmission in gear, not very safe at all.

Max_5gen

iTrader: (2)

You're correct about MT models but for AT model it doesn't make any sense IMHO. Unless the cable from selector shifts something inside transaxle mechanically. In that case this switch has to be synchronized with this shifting action and I couldn't find such procedure in FSM. So far it looks to me as a pure 'selector position sensor' which produces neccessary signals for control unit which in turn engages valves and does the actual 'shift'. It is interesting to know if my theory is correct in this regard and selector cable doesn't do anything besides moving this 'inhibitor switch' lever. Looks illogical though - so much trouble just to get the reading of the selector position ...

internetautomar

iTrader: (30)

it matters not whether it is stick or automatic. the transmission still has a physical connection to the shifter whether by cable or by linkage. The accuracy of knowing what gear it is in can only be done at the transmission itself.
see page at-9 of the 94 fsm. even though the transmission is "electronically" controlled it still has physical manual controls to know what gear it is supposed to be in.

Max_5gen

iTrader: (2)

I see, it shows "Mabual Valve" on that page as well as in other FSMs up to 2k2 (just the last one I checked). OTOH, AT does switch 'gears' on its own, so that 'Manual Valve' doesn't really put it in any particular gear but rather some kind of 'mode'.

For example, in my case switch didn't produce signal in '1' position and AT behaved exactly the same way in both '1' and '2' positions of the selector (and 'Manual Valve' as well) including switching to 2nd at certain rpms. To put it short - I have no idea how it works but you're correct that selector switches something inside transaxle through its cable.

eric93SE

iTrader: (1)

You can actually disassemble the Inhibitor switch and clean the contacts out. Most likely you bushings on the shifter cable have broken and fallen off the car, there is one at both ends of the cable. To get to the one above the CAT, you should be able to loosen the top most heat shield and push it back. You should replace both bushings even if one is still present.