84 w/CF won't start

[kmcewan]

CTS

Did a little reading on the CFI vault between messages and found that it is the coolant temperature sensor.

The cts isn't connected. The connector is hanging loose somewhere in the engine compartment. Sounds like something I need to fix ASAP.

Ken

 

[vigman]

Yes you DO!

Without your temp sensor.... the car doesn't know things it needs to!

Vig!

 

[kmcewan]

CTS

Vigman,

Thanks for the offer, but I have one on another manifold. I may even go to pepboys and buy one. I read somewhere where the replacements even have a retro fit connector.

Yes, I did adjust the IACs to just under 1 1/8th inch. Still did not seat after my 20 mile drive.

Twinnie said to short one of the connector pins to ground, but I realized that I didn't know which one he was refering to.

Sounds like the CTS may be screwing things up as well. Maybe that what's causing the hunting problem I have now.

Ken

 

[vigman]

Ken

AOL IM me...
vigmannn

 

[kmcewan]

AOL

Vigman,

I don't use AOL or instant messaging.

Never tried it. Do you have to be a member of AOL?

Ken

 

[Twin_Turbo]

With the CTS disconnected the ECM thinks you're driving on the north pole It will stay in the cold startup and deliver WAAAY too much fuel. With this problem the car can never run right.

You can troubleshoot the CTS, if you wire a 640Ohm resistor in the harness the ECM should stay in open loop.

The ALDL has a bunch og pinouts The 1st 2 on the upper row are ground & test, connect a jumper between the 2, then you'll go into field service mode. If you use certain resistors (as a jumper) you can switch the other modes. The scanner does the same.

0Ohm (a short) Field Service mode
3,9KOhm resistor -> backup mode = limp home mode.
rpm, throttle position & CTS are used for controlling fuel delivery
10KOhm -> special or ALDL mode, rpm is locked at 1000 rpm
infinite (open) normal driving mode.

As you can see the ECM detects a major component failure (CTS) yet it relies on it to adjust rpm (the limp mode) Idle will be very erratic and fuel delivery will be way too much, the engine is running severely rich.

You can check w/ the10Kohm resistor, if the idle stays nicely at 1000 rpm the CTS is your main problem.

Don't drive like this too much, the lockup in the tranny won't work!

Also, the excess fuel is washing the oil off the cylinder bores, causing more wear


Marck

 

[kmcewan]

Good News

Replaced CTS & found the shorting wire.

Results:

Car starts without touching the throttle & idles on it's own.

IACs are now seated and working.

Runs pretty smooth, but still a little sluggish when you tap the throttle. Balancing the TBs and rechecking the timing should finish the job.

All I have left to do is install the EGR Solenoid and connect the kick down cable and the intake is finished.

This has been an interesting learning experience and I couldn't have done it without all the help here on CAC.

Many thanks to :BOW Vigman, Twinnie and many others for all expert advice.

Many Thanks Guys,

Ken

 

[Twin_Turbo]

That's what this place is for

Marck

 

[vigman]

Whump there it is

Whump there it is,Whump there it is,
Whump there it is



Your welcome

Vig!

 

[Drewser]

Da, Da, Da, DAAAAAAA

GREAT news buddy! I knew you could do it. Welcome to the world of great running vettes. See you on the road soon with a few mustangs in your teeth!
--Drew

 

[kmcewan]

ALDL??

I feel stupid for asking, but what is it and where is it?

Ready to balance my TBs and need this info.


Couldn't find any reference to this in my Service manual.

Ken

 

[vigman]

ALDL

Assembly Line Diagonistic Connector

In the driver's compartment
About where you right knee would be... up & under the dash..

Down by Hush panel

Black connector

Cant miss it

Vig!

 

[kmcewan]

Problem Balancing TBs

Seated the IACs

Hooked up home made Mannometer to rear TB and it was measuring 2". Adjusted to 6" and it significantly improved performance and picked up the rpm.

Heres the problem.

Hooked up the mannometer to the front TB, and it sucked all the water out.

What's wrong?

Ken

 

[vigman]

To much suction.....

Strange..... need to see your home brew manometer to make a better call than that.

But it would appear the the front is doing more work than the back if you have that much suction.

If I remember correctly... the top of the runners are open to both sides.....not like the front fires the left side and the rear ...the right.

Confused

Vig!

 

[Twin_Turbo]

You did use the center port right? the other ones will suck the water out of the manometer

 

[vigman]

Twinnie

The center port is above throttle plates?
and the two others are below?

Vig!

 

[kmcewan]

Mannometer Problems

Yes, used the center port on both throttle bodies.

As I said, the rear showed 2" when I hooked it up and was able to adjust it to 6" without issue.

The front was done the same way, but it sucked the water right out of the tube.

Should the screw be backed out on the front TB before I do the test again?

The mannometer is constructed with 10' of 1/4" od clear plastic tube mounted flat on a 1/2" x 4" peice of plywood. Colored water was used.

Is it possible that the front TB is that far out of alignment?

Ken

 

[Twin_Turbo]

The center port is the one that connects to the little slit in the bore, exactly whree the throttle plate sits at 0 throttle. The vacuum is lowered there because of this "leak" to athmospheric pressure.

This is about what you should have built, it's done in a couple of minutes.

Ken, are your bores dirty? See if the little slit is not clogged.

Wich TB did you start w/ the pass side? If so, open the other side w/ the synchro screw (now the drivers side idle stop screw is your reference point) You DID follow the instructions closely right? If you turn both idle stop screws the synchro screw is defunct (if one plate stops on the stop screw and you close the other some more and that one stops on it's screw you'll OPEN the other one again)

Marck

 

[kmcewan]

Mannometer tests

Yes, the picture you included is essentially the same as what I have. Mine is mounted on wood.

As per the instructions, I started on the rear (drivers side) TB.

It measured 2" of water. Adjusted it to 6" as per the instructios.

Did the same tests with the front (passenger side) TB. Attached to the center port, and it immediantly sucked all the water out of the Mannometer.

I'll read over the instructions again, but I don't think I missed anything.

The TB bores are fairly clean execpt for a little carbon from previous backfires.

Ken

 

[vigman]

Do you have a regular VAC gauge?

If not... go to PepBoys and buy one
( around 20 bucks..) It will be useful later if your trouble shooting other VAC issues.

I assume when your doing these tests.. all unused ports are plugged.


It sounds like your getting FULL manifold vac (16-20 inches) from either not being on the correct port OR the plate is that far out of adjustment.

If you look down the throttle bores the idle STOP screw sets this dimension of the plates ALMOST being closed.

The Linkage & Syncro screw makes sure they open @ the same rate, So WOT is matched.

So if it sucked all the water out... you have managed to steam clean the top of your pistons...no big deal.

AND that's why I use VAC gauges instead of Manometers.


Vig!

PS did you find the Vac thermal switch on the dase of the air cleaner?