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Shiftless Automatic in a C4

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Oh right.... DUH??!!!

Ok

1) When you pull the air cleaner off.. do the squirters( accelerator pumps ) work?

2) Is the tranny a 700 r4?

3) You sent me the pictures of this ..correct?
If I remember, you were going to check if just the top was converted..or the whole engine was exchanged.. is the BLOCK orange?

4)What history ( if any ) do you have about the engine?

5)Dont give up!

Mike
 
D

Drewser

Guest
methinks you have the answer

With all the problems you have had with that bastard (and it IS too with a carb on it), I think you have the right idea in replaceing it altogther either with another 84 or prefferably with a hotter engine ala the Ken project. I would recommend a rebuild switching that carb for a good injection system (miniram or xram), but I have NO idea what is deeper in there, and you don't really either without tearing it all down. You seem to have that enigma engine. Good luck and keep us posted. BTW, do your engine numbers match anything or have you looked?
Drew :w
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
And....

We're just trying to get it running right...

Mike
 
Joined
Dec 27, 2001
Messages
160
Location
Matthews, NC USA
Corvette
1984 Coupe
This is what I know about the motor so far.

It's supose to be a new motor with only 4k miles.

It's got a holley and edelbrock intake. Original fuel pump was disconneted because it blew out all the seals on the holley. There is supose to be an inline fuel pump installed now.

Exhaust Manifold looks original.

Pullys and belts on the front of the engine look like original equipment for an 84.

Don't know the type of trany yet.

I Plan to get numbers off of everthing this weekend to determine exactly what I have.

Ken
 
P

Piet

Guest
Sounds like you have a money decision to make.

I usually end up in this dilema when I do home reno's
I want to call in a contractor, and just have him do it.
However, I usually press on and complete it.

The new engine will be some $$$

Tackle one problem at a time.
Start with the engine. Look at:

1) Fuel sytem, pumps, carbs, filters (It will really fry your bacon to find out your engine problems are caused by a $10 filter) You don't have any EGSV sensors?

2) Electrical System (Rotors, plugs, wires, etc...)

3) Finally mechanical (cams, chains, valves...)

Work through it systematically, to avoid frustration! :hb

Thanks for sharing the 'adventure'

-Piet
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Yet more

"It's supose to be a new motor with only 4k miles."

That should rule out the timing chain.. but we still need to check.

"There is supose to be an inline fuel pump installed now."

We need to verify that you have good fuel flow.

"Exhaust Manifold looks original".

OK not a problem at this point.

Don't know the type of trany yet.

Can you take a PIX from under the car?

I Plan to get numbers off of everthing this weekend to determine exactly what I have.

Good luck

Mike
 

Jack

Well-known member
Joined
Dec 27, 2000
Messages
1,825
Location
Florence, SC (Timmonsville SC)
Corvette
71 War Bonnet Yellow VERT 71 BH Blue CPE (SOLD)
?Fuel Pump: Mech OR Elec?

Ken:
Seems motor has been changed from original configuration ... Trying to determine what portion/combo of computerized engine management (if any) you have now:

Does this engine have a functional Mechanical fuel pump bolted to block? Normal position low on passenger side of block, toward front, just above oilpan-to-block mating line.

Are the module and pickup inside the HEI OK? Many parts houses offer a free bench test. If yours does, just remove them (easy) and take them down for test. They're CHEAP & easy to replace anyway.

Trying to identify the HEI-type here (computer or non-computer): How many ignition wires (plug/coil) does it have (8 or 9) attached to cap? Does your HEI have a vacuum advance canister (outside, near the cap-to-base mating line)? Is there an ignition coil (or place to put one) inside the top of distributor cap? How many Flat male pins/terminals does your module have (4 or 5 or 7)? Does your HEI have a group of wires (about 14 gage) exiting the base ... just below the cap-to-base mating line? If so, how many wires? Was your in-dash tachometer functioning normally?
JACK:gap
 
Joined
Dec 27, 2001
Messages
160
Location
Matthews, NC USA
Corvette
1984 Coupe
To my knowledge, nothing on the engine is computer controled any more.

Fuel pump is an in-Line elecrical.

Accelerators pumps on the carb are pumping gas normally.

The distributor is an standard late 70s early 80s HEI distributor with the coil in the cap.

Tach was/is functioning normally.

I'll be replacing the plugs, wires, Dist. cap & rotor this weekend, just to be sure.

What ever this problem is, it's definitly related to heat.

Ken
 
P

Piet

Guest
Do you have a little plastic vaccum valve on the engine connection to the top rad hose?

-P
 

singledad_9

Well-known member
Joined
Dec 7, 2001
Messages
189
Location
Glastonbury Ct USA
Corvette
Y2k vette, 73 under construction
Check the spark. I had a MGB that the coil went south and it was only when hot. The break in the wire would separate when the coil was hot. It was tough to start with no spark.

Had a bumper sticker "Parts falling off this vehicle are the finast British Manufacture"
 

Jack

Well-known member
Joined
Dec 27, 2000
Messages
1,825
Location
Florence, SC (Timmonsville SC)
Corvette
71 War Bonnet Yellow VERT 71 BH Blue CPE (SOLD)
new module

Ken:
Change the HEI module out when you do ig tuneup this weekend. With so many variables at this point, I realize new module is a shot in the dark. But, it could be central to this apparently heat-related issue ... and they're cheap & easy to replace.

Maybe you have two pumps ... in-line & mech? (why, dunno ... but possible bubba may've been there) Find the elec one & verify both its pressure-volume (somewhere between 4-9 psi should be plenty) & 12v supply.
JACK:gap
 

Jack

Well-known member
Joined
Dec 27, 2000
Messages
1,825
Location
Florence, SC (Timmonsville SC)
Corvette
71 War Bonnet Yellow VERT 71 BH Blue CPE (SOLD)
/ singledad_9
Had a bumper sticker "Parts falling off this vehicle are the finast British Manufacture"
:L :L :L
Reminds me of large sign on Elglin AF Base "Largest Mig Parts Distributor In The World"
JACK:gap
 
Joined
Dec 27, 2001
Messages
160
Location
Matthews, NC USA
Corvette
1984 Coupe
Good point about replacing the module. Might as well replace that too.

Don't know of any bubbas in NJ, probably a vito or vinny though.

"Not that there is any thing wrong with that"
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Ah HAH

After marking where all the wires go!
Remove the cap, remove the two screws holding the coil cover down & remove cover.

Observe closely.. the ground wire from the coil
(solid wire) & the jumper ( metal bar ) for ground to the cap electrical connector( on side ). And the two other wires as well. The coil pulls ALOT of current.. connections HAVE to be good!

The hold down screws for the coil are also part of the electrical connection to ground.These ALWAYS strip out.

The solid wire gets corroded at the lug ( poor connection)

The ground point for the wire & the metal bar are not always the same side so you have to use the coil frame to complete the connection.Check for corrosion.

Lastly.. Replace the Cap & rotor when you do these inspections.

There is also a 4 or 5 pin connector which goes to the old spark control.. did they tie into that?

Mike
 
Joined
Dec 27, 2001
Messages
160
Location
Matthews, NC USA
Corvette
1984 Coupe
Mike,

Just replaced the rotor and cap checked all the connections.

The car starts, runs a little better, but very rough at low rpms. Won't idle at 800 rpm which is were is was idling before.

I let tried to let it idle and it died. Tried to restart it and it kicked raw fuel out the carburator. Starting to sound like a timing chain to me.

If you ever took a major vacuume line off a carburator while the engine was running, that exactly how this thing is running.

I'd like to be sure it's not a vacuum problem before I take all the junk of the front of the engine to look at the timing chain.

Do you know a fool proof way to check for these problems?

Ken
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Fool proof..Hmmmmmm

1st
Check the timing with a light
(tell me where your initial timing is set.)
Also check the condition of your plug wires, FIRST!

2nd
Will involve removing all the plugs.
The basic idea is find where TDC lives.
You will need somebody to help you on this.

Car in neutral

Remove the power wire on the HEI cap.

Remove plugs, yes ALL 8.. also make note of what holes they came out of.. and their condition.
This will tell you how things are running.

Bump the enging over till the 0 on the timing cover index lines up with the line on the harmonic balancer.

Get a screwdriver and check that the piston is ALL the way up..If not.. your 180 degrees out.. spin again ( light bumps on the key)... once you find TDC on the #1 hole....

Remove the cap and swing it out of the way
Noting where the #1 wire is on the cap.
If the distrib was installed correctly the #1 wire
SHOULD point to the #1 cylinder.

Now see how much play you have in the distributor
there SHOULD BE NO PLAY as you try to twist the rotor cap IF you have the correct HEI distributor for an 84.. or minimal at best

( about 1/2 the distance between the cap contact your on & the next or 1/4 of an inch)

Get a breaker bar.. put it on the harmonic balancer
center bolt.

DO THIS CAREFULLY & SLOWLY,EVEN STROKES. Ive seen guys gorilla this and break the front bolt off
BE CAREFUL!!!!!

You still should be at the 0 mark with the timing

Now ready... Have somebody with the screwdriver keep in the hole to sence your movement, and keep their eye on the distributor to see when it moves.

Turn the crank 1 way... stop when you see the distributor move. Note the number on the timing indicator.

Turn the crank back the opposite way..stop when you see the distributor move. note that number.

The movement of the crank SHOULD be a direct motion
relative to the cam. If you have more than 8 degrees total, your chain is loose. more than 15 It's gonna jump any second.

If it's less than 8 degrees..I would bet the farm
that the setup is ok, and look elsewhere.


Your static timing should be 6 degrees BTDC.


Mike
 
Joined
Dec 27, 2001
Messages
160
Location
Matthews, NC USA
Corvette
1984 Coupe
Mike,

I'll try to give these tests a shot this weekend.

Checking the timing is while the engine is running won't work. The engine won't keep running below 900rmp.

The rest of the tests I should be able to do.

If this problem is cause by a major vacuum leak, it would explain the rough Idle and the problems shifting. Unless the 700 doesn't rely on vacuum to shift.

Sounds like I have my work cut out for me.

Thanks for the help.

Ken
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
A 700r4

Can't even spell vacumme, the only connection's are electrical & mechanical.

Tell me where the timing is @ 900 I dont care..it's a point of reference. Should be less than 10deg

Also check your manifold vac.. at idle it should be over 15 inches, unless you have a BIG cam.


Mike
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Other thought(s)

Have you tried driving it...does it have the same power ( in the gears you have left?)

The idle thing.. check and see if fuel is not PI$$ing out of one of the vent tubes..or it's just running way rich..you might have a needle & seat problem.

You COULD try moving the distributor a few degrees ( one way or the other ) to smooth things out, you might have to much inital advance in. Mark where you were BEFORE YOU DO THIS it will help to see if the cam chain jumped.

Does the engine shake when your at low rpm... maybe
a plug wires burned or a plug is fouled.

What carb do you have on it?

The electric fuel pump should be delivering no more than 8 PSI for a stock Q-jet or holley 650-700 ( need to measure this )

It would make sence that they dropped a different
engine in..but I'll bet the tranny is a 700r4..

Identifying the tranny
See if there is a cable that looks like the throttle cable atached to the carb and going down to the tranny ( this is the TV, throttle valve cable).. You still have the digital dash right, and does the speedo work? That would be another indication that the 700R4 is still in.. and lastly does the dip stick say on it Trans fluid on the top knob.


I dont think they would put a TH400 in there....


Is the bottom of the block ORANGE or gray/black?

Is the knock sensor still in ( by starter motor, center side of block above oil pan gasket seam)
and is it wired up? The ESC ( electronic spark control might still be active )

Sorry to ask all these questions.. but it is nessesary info to help via remote control.

I wish it was as easy as..turn this screw 1 turn and boom!

This car has been MODIFIED and as such we need to know whats left of the 84 electrics & whatever is different.
 
Joined
Dec 27, 2001
Messages
160
Location
Matthews, NC USA
Corvette
1984 Coupe
Have you tried driving it...does it have the same power ( in the gears you have left?)

No, it's runing so poorly, I'd be afraid go beyond the end of the driveway.

The idle thing.. check and see if fuel is not PI$$ing out of one of the vent tubes..or it's just running way rich..you might have a needle & seat problem.

Bingo! Saw this sunday and and again last night. Didin't think any more of it until you said something. One of the primarys was dripping fuel and there appeared to be a little puddling. I thougt it was unusual at the time but think any more of it.

If the carb is dumping large volumes of raw fuel into the intake, it could be fouling the plugs and making it harder to restart. Also, several dead plugs would explain the rough idle.

I noticed that at higher RPM things seem to smooth out.

I'd much rather replace the carb and add a fuel pressure regulator than to take the front end of the motor apart.
I mentioned earlier that this carb had to be rebuilt do to seals being blow out by an over pressure condition. Who knows what kind of rebuild job was done.

Ken
 

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