zekgb

Lots of things to investigate / work on after bringing the Green Machine back to California. For those who missed my other threads this is an 85 AT with 64k that is seemingly well maintained but has no service records. Some of these items may not be problems but just misunderstandings on how things are supposed to work.

1) HVAC Stuff
AC - Center vent blows cold (when cabin temperature starts cool) to cool (when cabin starts warm/hot). Side Vents always blow much warmer than center vents and are never actually cold. Center vents blow warm when AC is off regardless of Temperature selection. Very little air being moved out of lower center vent.

Questions: Should I be starting with the hot water valve? Are the side vents supposed to blow cold when AC is running? How much air should be moving out of lower center vent? Why the hell does my glove box feel like a refrigerator when the cabin is hot hot hot? (ok that last question is rhetorical.)

Low Idle - Engine idles at just above 500 rpm and is good except for an oh so slight stumble that can best be characterized as a blip that occurs every 15 seconds or so. I don't remember the stumble being there for the first day of driving and neither it nor the low idle was not mentioned at all by the shop that did my TBWP work, so I'm fairly certain we picked this problem up on the drive.

AT - With second gear selected, car will rev to 5500 rpm at half throttle in first gear before shifting. Launching in 3 or D with half throttle produces extremely quick shifts, somewhere around 2400 rpm or so. Launching with WOT in 3/D produces shifts around 3400 rpm. Launching the car with 2nd selected and then selecting 3 while the transmission is still in 1st gear results in an immediate upshift through 2nd to 3rd, even at WOT. Bottom line is that when anything other than 2nd is selected, AT wants to shift to top gear very quickly. Is some sort of vacum leak my most likely culprit?

Kick Down / Throttle - I can not get the car to kick down when 3 is selected, in D I must roll off the throttle slightly before mashing the pedal down, upshifts occur at 4500 or so. Should I be able to spin the tires in 2 with WOT from a standing start? I can not do so and suspect that maybe the throttle cable needs to be adjusted.


Charging Issues? - Getting a reading of anywhere from just below to just above 12V, what should this be reading in an ideal world? I plan on inspecting / cleaning as many of the grounds as I can get to, but would like to know what I am shooting for here.


So where should I start? I'd like to have a few easy victories before pounding my head against the more difficult problems. Of course advice on any of the specific items is appreciated.

Thanks in advance,

Kevin

Mike Frye

Hey Kevin,

Newbie here, so take it FWIW. I would start with idle first, because it could impact other stuff as well (idling low may cause undercharging, which could cause any number of other things...) plus it's pretty simple, especially if it wasn't like that before the tb/wp job.

I would start with looking for vacuum leaks around the intake above and below the MAF. Make sure all rubber is seated properly and clamps are straight and tight, all vac lines are secured and flexible, not dried and cracked. This will probably cure it, but if not:

Put a jumper in the connector at the top front of engine (11:00 and 6:00 I think, but check the procedure in the manual) and then adjust the idle screw (6mm IIRC). Once the idle is sitting on 750 take out the jumper.

This MAY fix other stuff, but at least it will make sure it's not the cause of any of it.

BTW- My battery gauge reads perfectly horizontal when idling, just over 13 v I think. It goes up very slightly when revving, and dips when something is running like wipers, or seat motor, sunroof motor...

Shark Attack

I would start with the driveability stuff

SharkSkin

Agree with Shark Attack -- Driveability first. The voltmeters in these cars don't always read correct voltage anyway. In my case it was resolved by cleaning up all of the connections leading to it -- in the process of cleaning ALL of the connections.

Check the actual voltage at the battery so you know how far off the gauge is, and drive on(for now).

F451

What' the story with the timing belt, tensioner, cam gears, water pump, etc?

Have they been replaced lately? If not, I would figure on doing that soon.

How about the flex plate pressure? Has that been released lately? Crank end play been checked lately?

And I would check out the braking system from front to back and renew anything suspect.

Then I would get into the other things on your list.

Good luck. -Ed

ps: I'm a relatively newbie here too, so am just passing along info I have learned from our more knowledgeable listers over the last 1.5 yrs here.

pps: '85 autos rock!

Bill Ball

The odd shift point and downshift behavior could be a maladjusted "Bowden" cable. I would check that first. This cable runs from the throttle quadrant down the back of the motor along the top of the TT to the tranny. Figure out which one it is on the quadrant and pop the ball end off the socket. With no slack in the throttle cable, adjust the ball end screw adjuster of the Bowden cable so it is lined up with its socket with no tension then pop it back on.

The side vents should be the same temp as the center vent. So, they are seeing different distribution. However, I would check the heater valve first. Make sure it is moving closed when you switch the AC on or have the temp set low. If not check for vacuum at that line. Even if the valve closes, the internal guillotine mechanism may not be sealing completely. None of the vent air should ever be above ambient temperature with the temperature set below ambient and the AC off. If any vents are warmer than ambient, it is evidence the heater valve has bought the farm and should be replaced.

zekgb

When is WOT not WOT?

When the plastic trim covering the HVAC access panel is not tucked in behind the go pedal assembly Pedal was hitting the plastic just and stopping at about 90% throttle. Kickdown / slow launch problem solved. I also noticed a fair amount of slack in the throttle cable and adjusted that out. I thought the car was fast before, yikes.

Still have the weird shift behavior to deal with, as soon as I fixed the above I HAD to go on some test runs....

Bill Ball

When you take slack out of the throttle cable, that can affect the Bowden cable setting too. Check that as I mentioned.

Yeah, with slack in the throttle cable the car will not reach WOT. Take slack out, as long as the idle switch still clicks when you return the throttle to the idle stop.

WICruiser

As mentioned above you really need to start with the critical stuff unless you have records you can believe in, Timing belt failure or thrust bearing failure can be life threatening to your shark so before you spend much time or any money fixing other things - 1) Release thrust plate and check end play and 2) replace timing belt and water pump. There are while you are at it items that can be done while you are at it but I hate it when we hear of someone that just spent a lot of time and or money fixing up a new to them shark only to trash the engine.

zekgb

Sorry for not mentioning it in this thread but my previous threads covered the TBWP/Flex Plate/Crank end play check that were performed prior to picking up the car in Jacksonville. I would definitely have not driven across the country without those items being addressed.

Kevin