poor running 84

[geekinavette]

thanks again--------keep ya posted

im readin 6.0 milli volts thats in the plud disconnected

The TPS must be connected to check the adjustment. Oh and do this with the engine NOT running! :L

 

[wishuwerehere82]

thanks again--------keep ya posted

im readin 6.0 milli volts thats in the plud disconnected

You need to put some paper clip leads or some sort of extenders in the connector to connect your Voltmeter leads to.
The voltage reading must be made with the TPS sensor connected.

 

[frank dye]

Hi,
I had similar problems with my '84. You might want to re-check your vaccum hoses. Particulary behind the throttle body on the passengers side. You also have some wiring behind the battery that is directly linked to the amount of fuel you're getting (I had that problem also).
good luck!
Frank dye

 

[wishuwerehere82]

Also as I recall...I think you can put the ECM in diag mode (connecting pins A and B of the ALDL terminal) and "home" the IAC valves, meaning they would be fully closed...taking the IAC valves out of the picture. Pete do you recall if that's how to do that? It's been a while...

Also, the IACs won't operate "normally" again until the car is brought up to 35MPH or so (I think it's 35...).

According to TwinTurbo, you connect ground "A" to the diagnostic "B" on the ALDL the same way you would read the codes, and it will cycle the IAC motors.
I have never done it myself, and since I installed IE7 I can't log into the Crossfire forum to confirm it. Can you check it out?

 

[chevyagain]

checked TPS hooked up 138.1 MV, NOT READING VOLTS

 

[chevyagain]

my # 1 wire is the first wire to the left of square bump out
for tach, ign. on dist cap, drivers side

 

[wishuwerehere82]

checked TPS hooked up 138.1 MV, NOT READING VOLTS

.525 V = 525 MV . The TPS is set too low, and you are not getting any fuel at idle.

 

[chevyagain]

not getting anywhere near thet .525 unless im doin wrong im gettin readings of 192mv moving sensor. set it where i think it should be
too much gas, flyin out of tb. cant quite understand how moving
the tps changes the voltage

 

[wishuwerehere82]

my # 1 wire is the first wire to the left of square bump out
for tach, ign. on dist cap, drivers side

Here's how it should be wired.
Note the wire position on the cap, in the first picture.

And the position of the distributor set at 6 degrees BTDC as viewed square-on from the fender across the engine compartment, in the second picture.

Notice how the distributor is angled just about 3 degrees off of center.

I'm going to take some pictures of the TPS settings in a few minutes. I'll be back!

 

[wishuwerehere82]

The TPS is attached tp the rear TB by two screws, and has a 3-wire connector.
The Voltage measurements are taken from the bottom and middle wires.
I have removed a small patch of insulation from my wires to get meter leads on them.

The TPS is adjusted by rotating the body of the TPS pivoting around the wiper arm that contacts the throttle linkage. The body at the connector end is pushed up to increase voltage and down to decrease voltage. The TPS will slide on arched slots under the screw heads, so just loosen them enough that the TPS can be moved, but tight enough that it will stay where you set it.

Make sure your Voltmeter is set for DC Volts, and on the Millivolt setting.
And rotate the TPS until you get 525 Millivolts DC.
Mine is a little low, due to an add-on module (not in the picture).

 

[chevyagain]

thanks 82 the pics are great, gonna start over, this is not going to beat me
got too much time into it. besides as they say, its a learning thing
thanks--------john
will keep posted

 

[wishuwerehere82]

Just make sure your rotor is pointed at the #1 plug tower with the crankshaft at TDC on the conpression stroke when you move the plug wires around.
Even if you have to pull the distributor and rotate the distributor shaft to do it.

 

[chevyagain]

new problem guys, battery keeps going dead, this is a brand new one
nothing left on, always checked, no lights on console open or nuttin
wndering if its tha ECM AFTER ALL any input always appreciated
this is about the fifth time its happened

 

[wishuwerehere82]

Slap a charger on it and let it charge overnight.
Without running it, cranking it over and over will kill the charge pretty quick.

 

[chevyagain]

got TDC on compression stroke, went over wires rotor just a hair before
# 1 post on dist. cranks and cranks, turned dist both ways slightly
nothing. im about to through in the towel. think i gotta get a crossfire
guru here, never had this much trouble----------john

 

[wishuwerehere82]

Let me understand.
1)You moved the distributor body around so that the connector position looks like the pictures I attached.
2)You moved the wires to match the location on the distributor cap as seen in the pictures. And you verified that the wire # on the distributor goes to the correct spark plug.
3) You pulled the distributor out and rotated the shaft so that at TDC on the compression stroke, the rotor points at the #1 plug tower.

Are you getting a spark at all? You can put a timing light on the #1 plug wire to see if you are getting a flash as you crank it.

If not. Sometimes the spade lugs on the distributor connectors can push up into the coil cover and not make connection. You can take off the coil cover and push the lugs back down into the Batt. and Tach. connectors to make sure they're seated.

 

[Buccaneer]

Hi guys, new to site, but not crossfire. Lots of years on CFI vettes alone.

I had to read this whole thing from the start to get and idea wtf is going on with the motor. Everyone has good inputs like Bill and wishuwerehere82. I think they are on the right track.

Not sure really where this motor is at at the moment though. Is it still backfiring through the TBs? Still not staying running? etc... This may be a lean pop which goes back to FP. Do you know what the FP really is at the moment, it's really important on a CFI motor and 14psi works just fine on a stock or slightly modded motor.

A vacuum leak is also a very likely suspect with this issue. The top plates as mentioned are a good place to start along with the TB shafts. If the shafts move at all, they are bad and are leaking to atmosphere (vacuum leak) and need to be bushed...PERIOD! This will also cause a high idle, erratic idle and stumbling. Vacuum lines also need to be checked for cracks etc...

So I gather that you don't have a CEL, right? If the light is out, that would indicated that the issue is either not controlled or monitored by the ECM, which goes back to either a mechanical adjustment, fuel or something related.

Your TBs could be way out of balance as well as stated. However, you have to find the root cause first before you just start tweaking everything. If you do the balance wrong, it will be really wigged out. I didn't understand what is going on with the TPS either, .192mv is WAY TOO LOW. The closer you are to .525mv the better.

I hope you get your issue(s) resolved soon...Push come stove, trailer that bad boy out here to Arizona on a road trip and we'll get her going for you in no time. We have the experience, know how and tools to "Getter Done".

Good luck and post your results.

 

[wishuwerehere82]

Welcome Buccaneer!
We need some more heads to put together and get this problem solved.

 

[geekinavette]

Maybe a quick "check" of the ECM is in order....

First of all...do you even get a Check Engine light when the ignition is on with engine NOT running?

Check for trouble codes. Take a paper clip and jumper pins A and B of the ALDL connector, then turn ignition on (again, don't start the engine). The Check Engine light will flash some codes like so:

FLASH <pause> FLASH FLASH (longer pause, repeat two more times)

This is a code 12 (one flash, a pause, then two quick flashes). This code just means there is no distributor reference pulse (ie engine isn't running), and is the first code you should see (and only one if there are no others stored). The ECM flashes each stored code three times, then starts over. If there are any other codes stored they will flash after the code 12.

If the ECM doesn't do this...then there is a problem with it.

As for the battery drain...there are a hundred possibilities. The instrument cluster is a common culprit...specifically the trip odometer circuit. With the ignition off, pull out the LCD fuse...then re-insert it slowly. If you see any tiny "arcs" when you stick the fuse back in...your trip odometer memory circuit has a "current leak" and is draining the battery.

 

[chevyagain]

first let me say thanks to all the input and help, however its beyond my control now. did jumper A&B no codes, never had codes with car running
and no jumpers. tried to start this am big big backfire at rear TB
i did notice with ignition on rear IAC kept going on and off i approx
2-3 second intervales nothing from front IAC. im beginning to think
computer not hooked up or bad no BUBBA bad boy.
im really in a rural are here in va. these guys think a crossfire
is a campground term, HA,HA. i am tryin to get someone here from
a chevy dealer who i spoke to and knows these campfires i mean
crossfires, little joke there. computer on drivers side correct??
hard to get to??? THANKS ALL--------JOHN