KDMatt

Also, still no sign of the EST wire anywhere??

KDMatt

I'm officially stumped.

With the IACV's disconnected, following the procedure you gave me, the idle is actually now at 1700 rpm.

The FSM says with both TBI's synced I should be able to adjust the idle with just the rear TBI minimum air valve... I've backed it off at least 3 turns (counterclockwise) and the idle hasn't changed at all... if anything it's gone higher??

I know you guys aren't really Crossfire guys, but I can't find anything online, and the FSM is vague at best. It's saying I need a special tool to block off the idle air passages before I can adjust anything? Does this sound right??

Giving up for the night.

Bob88GTA

iTrader: (2)

Good morning Matt
I got some more info for ya concerning the location of the EST on a Cross Fire.
On a crossfire car, the EST bypass connector is behind the passenger side valve cover. On an original harness, the black stripe may have smeared off (it was painted on) and the wire may appear more brown that tan. The tan/brown wire is not tucked into any of the wiring harness cover, so it should be easy to see. The wire goes into a small black one-wire connector.

If you don't remove the connector, the computer controls the timing and you will see the commanded spark advance (i.e., the 28* you saw). When you disconnect the connector, the computer no longer controls timing and you will see actual initial advance. So you MUST disconnect the EST bypass in order to set initial timing.

As far as the high idle go's, did you jump the ALDL terminals, turn ignition to on for 30 sec, unplug IACS, turn ignition off, start car, adjust idle screw to 400rpm, turn off, connect IACS, start car and it should idle at 600ish.
I'm a little lost....

KDMatt

Bob - I jumped terminals A and B (which I found really just sets the check engine flashes) and turned the key to the 'on' position. It was in this position for at least a minute as I waited 30 seconds before I started removing the IACV connectors. After the IACVs were disconnected I did not turn the key back to off, I just started the car, and the idle was sitting at about 1500 RPM.

Riddle me thoughts on the coolant temp sensor? I hopped over to a crossfire section of a corvette forum and saw a guy with an '82 Camaro CFI that was having high idle issues due to a bad coolant temp sensor -- the theory being it was reading an incorrect cold temperature and keeping the IACV's wide open. Is that still possible, even with terminals A and B jumped on the ALDL?

Also, thanks for digging around for info on my EST connector. I'm still looking for it. I guess we'll see what I come up with tonight??

Thanks again, man.

Bob88GTA

iTrader: (2)

Once IAC's are unplugged after comanded closed, there is no power to them at all. They HAVE to be closed. Is your throttle stop screw backed of of the adjustment plate when it idles at 1500? Can you physically pull the throttle back to lower it? Is you gas cable/pedal work freely? IDK, now I'm scratching MY head.

KDMatt

If they're commanded closed, I should be able to look down there and see that they're closed right? That's one thing that I didn't check.

Will incorrectly set timing make it idle this high?

Bob88GTA

iTrader: (2)

Yes, and yes. If timing is too advanced, the idle will def be higher.
Happen to find that EST wire yet??

KDMatt

Not yet. Part of the complication is that I'm usually writing and responding to you guys from work, and it's not usually until about 9 or 10 o'clock that I end up working on the car again, so I'll check when I get home.

Bob88GTA

iTrader: (2)

did you measure your CTS? Do it when cold.

Bob88GTA

iTrader: (2)

YOU BETTER GET BACK TO WORK!

Bob88GTA

iTrader: (2)

When you get this up and running, I'm driving to Minn for that Beer!

red rock

iTrader: (2)

Me too Bob, I'm only a hour away. A bad temp sensor and poor timing will create a high idle problem.

KDMatt

For real! You guys have definitely earned it. My basement mini-fridge/bar is always stocked with Miller, and we rotate other brews around depending on what we're in the mood for.

A new coolant temp sensor is only about 13 bucks. I'm thinking I should just grab a new one on my way home and not have to worry about it again for a long while.

Oh, and I found a really thorough tutorial on adjusting CFI for Corvettes. I really do wish the Trans Am hood opened back to front like the 'vettes do. That would make it so much easier to work on. d'oh!

http://www.superchevy.com/how-to/468...system-tuning/

EDIT: Here's another one: http://temp.corvetteforum.net/c4/vader86/baseidle.html

red rock

iTrader: (2)

Matt, by the time you get this thing dialed in, your going to be an expert on cross fire. And by the way, when the beer is free it doesn't matter what brand it is.

KDMatt

Thanks for the vote of confidence!

I've worked on both Bosch L-Jetronic and Bosch Motronic EFI systems, and to a lesser extent the GM TBI system on my old Saturn. At some point when you've worked on one EFI system you've worked on them all -- it just becomes a question of figuring out each system's quirks.

KDMatt

Okay guys, update time.

Sorry this has taken me so long -- my lady and I are celebrating our anniversary this week, so other things have taken priority.

Okay, so, here's what's going on now

1 - found the EST wire! It was, as you mentioned Bob, behind the passenger side valve cover. The reason I didn't see it was because it was hiding behind the oil dipstick. However, I still can't see the timing marks anywhere. I know you linked a pic but I seriously can't see any sign of the plate down there. If it's really buried down there, I'm going to have a hard time getting my timing light down there anyway. The metal fan has already knicked it a couple of times.

2 - I replaced the coolant temp sensor, and that's been a big big help with my idling problem. In fact, as the engine warms up I can hear the IACV's beginning to close up. The whistling noise I was hearing before while I was driving along? Air whistling through the IACV openings on the throttle bodies.

Here's the thing though, the IACV's aren't closing all the way. Even with the engine warmed up, even in "closed loop" operation, I can still put my fingers over their air passages and feel air passing through them... this probably explains why I can't dial the air down with the minimum air adjustment screw.

Here's the even stranger part though, with the IACV's connected, the engine is idling at a nice steady 850 rpm in park (and about 600 in gear), when I pull off the connectors, the idle goes up to 1500 rpm. I'm not sure what the ECU is using to meter the idle speed, but it's not the IACV's.

3 - The stumble in the idle around 1200 RPM has been reduced a bit, but it's still there. There's also a bit of a power gap around 1200 rpm too. I'll be nice and smooth and steady, kind of "hiccup" around this engine speed, and then be smooth and steady the rest of the climb through the RPM's. Also, I'm not sure, but I think the TPS is messed up. It's reading over 4.5 volts with the throttle closed, and about .55 volts at WOT. ... I thought it was supposed to work in reverse? I'm thinking I'll just try to replace this sensor anyway. It's sort of the theme of my tuning here.

4 - I'm getting a bit of dieseling at shutdown, even with super unleaded, could be due a bit to my timing not being spot on (even though I've been fiddling with it,) though I'm wondering if it has to do more with those IACV's remaining open, and having a generally leaner mixture thanks to a more accurate coolant temp sensor.

5 - I'm realizing the car wanting to die after coming off a freeway jaunt is less about the idle control mechanisms and more about the transmission. I'm noticing that once the car locks into 3rd gear for a while it doesn't want to let go. It's dying when I come to a stop because it's not releasing in third and it takes the engine almost coming to a complete stop before it finally disengages. If I shift it down into "2" as I'm coming to a stop, the car is fine and disengages normally.

I'm not much of an AT guy, but I know there are kickdown switches and cables that run from the throttle to the transmission and all of that stuff. On one of our other cars (a Jeep) I know it's common to have to adjust these cables periodically to keep the transmission in sync with the throttle position. Is there an adjustment like this I can look at?

Granted, I could also just take it in to a place like Kennedy and have them service the trans. It was down about half a quart on trans fluid when I first got it, and even though the fluid is nice and pink, and sitting at the right levels, it might still need some professional attention.

EDIT: The other reason I ask about transmission adjustments is because it seems like it's shifting through the gears really early, and I really have to nail the throttle down to get it to downshift, sometimes, depending on the speed, it doesn't downshift at all.

EDIT EDIT: Is this transmission computer controlled or mechanically controlled? If it's done with a computer, perhaps the wonky TPS is part of the shifting problem.

What are your thoughts, guys?

Bob88GTA

iTrader: (2)

Matt,
The timing plate is gonna be a plate behind the harmonic balancer. you should be able to aim it through all the pulleys on the drivers side, unless its gone

The TPS if reading 4.5v, you got the wrong wires. It's the top two, black and blue as it is on mine, but I'm an 88 TPI. PM me your phone #

Bob

Bob88GTA

iTrader: (2)

KDMatt

Hey Bob, I'll check again when I'm at home (I'm up in WI until tomorrow) but the readings I was taking were off of the top two wires. FSM confirmed that's where I was supposed to take readings from.

Thanks for the pic, btw, I'll check again, but I don't remember seeing a plate down in that particular position.

Bob88GTA

iTrader: (2)

Hey Matt, I'm home all day tomorrow doing the Alabama BBQ thing. I'll call ya and we'll try to get this dialed in; no biggie.

KDMatt

Okay guys, thanks to a bit of timely guidance from Mr. Bob88GTA, I've just about got the idle on this thing dialed in.

Found the timing marks buried down under the waterpump, and the EST wire behind the oil dipstick.

I could tell that a big part of my problem was that the driver side IACV was not closing all the way (producing the 'air whistle' sound I was hearing,) and Bob recommended taking the unit out again and cleaning the hole that the pindle seals. I shot some carb cleaner in there for good measure.

When I was adjusting the TPS I observed that the PCV Valve was loose and could be easily withdrawn from the valve cover. Bob said that this shouldn't be the case, so I ran to AZ and replaced both the rubber grommet and the PCV Valve itself.

Between these two minor fixes, along with correctly set timing, the CFI 305 has become a totally different beast. It seems to be idling very smoothly, and produces relatively smooth power throughout the powerband. (Still got a little stumble around 1200 rpm, but it's a lot better)

I still need to fiddle with the idle screw I believe, since it's still a smidge high, but I can at least hear and see the computer now has control over the idle speed. It was actually "hunting" for the correct idle speed when I first got it all hooked back up, telling me that I need to go back and set the idle speed screw.

Sadly, this still hasn't rectified my transmission issue (it was still struggling to pull itself out of third when I came to a stop) but it as at least running measurably better.

Any word on adjustments I can make with that?

Also, Bob, I said it before, but:

Bob88GTA

iTrader: (2)

Have you done a filter change on the tranny? It may help. Also, the valve body in there MAY be gummed up and not letting the trans disengage out of 3rd. If it had OD with lockup TCC solenoid, I would say that the solenoid was faulty. But that's not the case with yours.

KDMatt

I haven't touched the trans, short of adding a bit of fluid to it after I brought it home. I'm not really an AT guy at all and wouldn't really know the first thing about servicing it, at least not yet.

Bob88GTA

iTrader: (2)

The filter change is relativly easy. Drop pan, 2 bolts for filter, pull filter and O-ring on filter tube, and re-install. If you don't feel comfortable removing the valve body, you could go to AAMCO and have them do a diagnosis on it. They ARE the transmission so called experts!

KDMatt

I've actually had really good luck with Kennedy in the past, so I might give them a call.

I'll check the FSM first though and see what the procedure looks like.

red rock

iTrader: (2)

Here are some links to adjusting the trans cable. https://www.thirdgen.org/detent and here is another; https://www.thirdgen.org/forums/tran...djustment.html If your trans cable isn't adjusted proberly, you won't have enough line pressure for the trans to shift properly.

KDMatt

Thanks for the links red!

I fiddled with the TV adustment at the throttle bodies... it's a bit trial and error as far as I can tell. First adjustment I did (with the adjuster set to the zero point, as per FSM,) the shift points were way too high and very rough. With the current adjustment, the shift points are a lot closer to where I'd expect them to be, but the quality of the shifts is still a little abrasive... However, it's letting go of third when I come to a stop after a highway jaunt, so that is at least improved. It's also downshifting easily and responsively.

How smooth are the shifts supposed to be? I think I'm still going to fiddle with the cable a bit more, but I don't want to go too crazy. I don't want to inadvertantly adjust it to make the shifts too sloppy or loose.

Getting very close to having this thing dialed in.

red rock

iTrader: (2)

I have a Trans-Go shift kit in mine set up for very hard shifting. The factory shift was really smooth on my 700R-4 when i got it. All i can tell you is, a smooth shifting trans. is built for comfort from factory and they are built to slip which puts more wear on the bands. A harder shifting trans. has more line pressure which in turn is actually better for the transmission. If you have it performing better than it was, i would keep it in that "sweet spot". When you pull the trans. dip stick out and look at the fluid color, is it a new red look or a dark red? Maybe as Bob88 suggested, you should change the fluid and filter.

KDMatt

Mmk, so, in general, "harder" shifts are generally better for the longevity of the trans? I have a 200c btw, not a 700r.

Last time I checked the fluid it looked like a nice dark pink, so it's showing a little bit of wear, but not it's not burnt. You guys are probably right though, in that a new filter and some new fluid would probably be good for it.

red rock

iTrader: (2)

Yes i seen you have the 200 trans. in your sig. The difference is a shorter 1st to 2nd gear on the 200 vs. then 700 and i think the 200 doesn't have overdrive. Internally they work the same. Some say the 200 is not as strong as the 700, but i don't know that much about them to say. Stick with it and maintain it till it doesn't work anymore.

KDMatt

Aaaalmost got the trans into the sweet spot. It was doing very very well during my test drives last night. I decided the only way to decide for sure if I'd figured it out was to put it through a real world test, so I drove it to work today. I have about a 25 mile commute, mostly freeway, so a good test.

It stuck in third a little bit during a decel in rush hour, but didn't do it again after that. This tells me I must be very very close to having that TV cable adjusted perfectly. I'll tweak it a little bit more before I head home.

Also, is it supposed to idle high when the engine is cold? ... Right now it's not. It's still holding itself at 800 rpm or so in park even on a super cold start. I would have figured most cars try to idle a little higher until warmed up. Maybe now the IACV's aren't opening to let more air in for cold idle?

aaaaalmost there!

Bob88GTA

iTrader: (2)

It IS supposed to idle high when the engine is cold. True statement, then idle down as it warms up; about 650 rpm in drive.

Sounds like you're on the right track, but I would at some point get the trans filter changed out.

Glad to hear all is well. Stock that fridge, me and red rock are heading your way!!!!

Of course he'll get there first!

KDMatt

Hmm... I'll check the FSM about fast-idle stuff... is it possible to accidentally thread the IACV's in too far or something? I feel like that would be a silly thing to keep them from opening, especially weird since, Bob as you can attest, there was an automated idle speed adjustment before.

I popped one of the old IACV's back in (I managed to break one of the new ones... long story...) so perhaps it's mechanically stuck closed.

I'm going to need to find a test procedure for them.

Bob88GTA

iTrader: (2)

Just don't take the IAC out and connect the connector to it and turn the ignition on...........the pintle will shoot across the garage and shoot you eye out!

KDMatt

I know, you told me this already when we talked on Sunday. I was listening you know!

Bob88GTA

iTrader: (2)

Just making sure!

red rock

iTrader: (2)

I don't know about you Matt, and maybe Bob also, but this thread has been one of the funnest ones to participate in. Working together to accomplish a goal and joking a little too. Keep up the good work guys.

Bob88GTA

iTrader: (2)

I have to agree with you redrock; working together and follow through it all from start to finish. Too many threads on here end in the comment " well, what ever came of this?". I enjoyed it, it was fun and gets you brainstorming to come to a solution. And ya gotta have fun and add a little humor to it all. If ya don't, it'll drive ya nuts!
Still a little fine tuning, but with time and patience, it'll happen!

Been a pleasure Matt. Good to put a voice to a name also!

KDMatt

Awww shucks you guys.

... don't leave me yet though!

... but yeah, I hear you. I've been around many car forums, and threads often die off, or people don't listen to what other people tell them, or don't take any initiative, etc. etc. I've seen the full gambit, and I'm glad to not have guided such a thread!

Bob88GTA

iTrader: (2)

we're here for ya Matt!

KDMatt

Okay, got the idle all sorted out, so now she idles nice and smoothly at cold temps, and nice and "low" at warm temps.

The trans is shifting nicely, and only occasionally does it seem like it wants to stick in third. I'm thinking a filter and fluid change will help alleviate the rest of my issues with it. It's also kicking down to 2 on the highway below 45ish when I punch it, which is precisely what I want it to do.

The rest of the work I have left seems like nagging little things. The revs are still a bit unsteady from time to time (there's still a gentle little hiccup around 1250 rpm) and I'm thinking about replacing the fuel filter... if nothing else, I'm sure running a few cans of seafoam through the thing has freed up some sludge and varnish that might now be trapped in the filter... problem is, Autozone can't even special order it apparently? Is there a special source I need to find on the fuel filter?

Other stuff I need to work on are nagging little things... For one, the tachometer is still completely bonkers after the car warms up. I've cleaned up the send signal at the dizzy, so I know it's not that... the fact that it keeps erring on the 'higher than actual rpm' side tells me that there's too much resistance on the circuit, or it's not getting a proper 12v at its positive terminal. Either way, I'm going to need to take apart the dash and take it out to see what's going on... that'll also give me a chance to clean up the contacts on the headlight switch, as I think that's going a bit wonky too.

The driver's side door seems a bit saggy (not to the extent that it's affecting the mechanism, but I'm worried about it eventually becoming serious) ... is that a big ordeal to fix? Also it looks like one of the retaining springs on the door handle is busted, so the handle kind of wiggles around.

Let's see... what else...

There's a squeak coming from the left rear suspension as I go over bumps... Is that likely something I can grease/lube, or is that a joint on its way out? I'm not eager to pop a wheel off and disassemble suspension bits, but so long as it's not a shock or spring I'm not exactly averse either.

Oh, and the power locks aren't working. I can hear them trying when I press the buttons, but I'm guessing they're gummed up or something. With the power lock and power trunk actuators working, I'd be tempted to rig up some kind of keyless entry system.

Other than that, I've really been enjoying driving this car around. The last couple of days it's been nice enough for me to pull the T-tops off after work and commute home that way. Being stuck in traffic doesn't suck nearly as much when you have miles of sky above you!

red rock

iTrader: (2)

Your fuel filter is an odd one,as for the squeak in the rear, the lower control arm and panhard bar has rubber bushings. Try spraying some WD-40 on them and see if the squeak goes away. The door has some adjustment in it, but after a while you probably will have to replace the door pins and bushings. Your nice days are running on a short time frame. I already put mine to sleep for the winter.

KDMatt

The Trans Am has a surprisingly good heater. I might keep her out for another few weeks. I only avoid the roads with the classic cars once the salt starts being poured on the roads, which is usually mid/late November, depending on what old man winter decides to do to us.

red rock

iTrader: (2)

I hear ya. I don't drive mine that much anyway. Car Shows, Rock Falls raceway, occasionally i pave the blacktop with rubber.