81 dies on acceleration. Need some E4ME and computer help.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
Will check. I'm guessing not though. Didn't get to work on her tonight so will check tomorrow. The sol mix screw, where is that? In pic, line looks like it is going to middle carb fixing screw
Whilst I remember, any idea what size internal diameter hose is required for the larger vacuum ports?
Thanks again for your help.
Whilst I remember, any idea what size internal diameter hose is required for the larger vacuum ports?
Thanks again for your help.
Last edited by jotto; Apr 10, 2013 at 07:30 PM.
Racer
Joined: Mar 2003
Posts: 448
Likes: 21
From: Klein Texas
From the finish, that carb is a "rebuilt" model from a parts store.
The circled screw in the pic is just that, a screw.
There are two adjustments on the MC solenoid, the lean stop and the rich stop. The lean stop adjustment is just in front of the idle air bleed. The idle air bleed screw looks low. When everything is properly adjusted, the idle air bleed has only a couple threads showing. The mixture control solenoid usually has about 1/8 of travel. When unplugged or an open solenoid, it should go full rich. (main metering circuit)
What usually happens is the o-ring on the air bleed goes bad and people tighten down the screw, restricting the air and richening up the mixture.
The circled screw in the pic is just that, a screw.
There are two adjustments on the MC solenoid, the lean stop and the rich stop. The lean stop adjustment is just in front of the idle air bleed. The idle air bleed screw looks low. When everything is properly adjusted, the idle air bleed has only a couple threads showing. The mixture control solenoid usually has about 1/8 of travel. When unplugged or an open solenoid, it should go full rich. (main metering circuit)
What usually happens is the o-ring on the air bleed goes bad and people tighten down the screw, restricting the air and richening up the mixture.
Last edited by David Mc; Apr 10, 2013 at 07:52 PM. Reason: edit: Have you checked fuel pressure?
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
Will check. I'm guessing not though. Didn't get to work on her tonight so will check tomorrow. The sol mix screw, where is that? In pic, line looks like it is going to middle carb fixing screw
Whilst I remember, any idea what size internal diameter hose is required for the larger vacuum ports?
Thanks again for your help.
Whilst I remember, any idea what size internal diameter hose is required for the larger vacuum ports?
Thanks again for your help.
that is why it looks funny.
the idle mix screws are not visible in the pic.
they are at the same level as the PCV port, 1 on each side.
couls have plugs still in and will lppk like the plugs on top but bigger diameter.
if the plugs are out, they will be slot looking screw heads.
think the blade of a standard screw diver, not the slot one goes in.
check yours.
Last edited by calwldlife; Apr 10, 2013 at 08:38 PM.
Burning Brakes
Joined: Oct 2011
Posts: 956
Likes: 86
From: McDonough Georgia
I have been following this thread and feel your pain.
You may want to find another carb and simply bolt it on without all the hoses and see if it works. Like maybe a Holley.
If it seems like your problem is better, then get an inexpensive HEI distributor from Summit and leave the q jet and CCC behind.
The only things you need vacuum for are the heat/AC switches, PCV, power brakes and pop up headlights.
Just a thought.
You may want to find another carb and simply bolt it on without all the hoses and see if it works. Like maybe a Holley.
If it seems like your problem is better, then get an inexpensive HEI distributor from Summit and leave the q jet and CCC behind.
The only things you need vacuum for are the heat/AC switches, PCV, power brakes and pop up headlights.
Just a thought.
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
As I have said in another thread....what is the challenge in that??? The CCC is a nice system considering the era...it will give a better avgerage 14.7 ratio than a QJet for everyday driving. Now if the car is going to be raced....get rid of the CCC.
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Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
Hey guys.....
So I reconnected the PCV and the MAP sensor.
I plugged the headlight vac feed and the brake servo.
Still no go. I tried the straw trick and pretty sure I saw no movement. I did take a video shown below but it was real difficult to hold her steady and what looks like movement in the vid wasnt apparent to me. I tried to keep my line of sight in line with top of straw and passenger fender.
Also, in diagnostic mode, no clicking is heard from the MCS.
UPLOADING VID NOW.
If I disconnect the 4 pin connector from the dizzy and put on a non computer carb, that would at least tell me if the actual carb was the problem wouldnt it?
If that was the case I could rebuild it.
So I reconnected the PCV and the MAP sensor.
I plugged the headlight vac feed and the brake servo.
Still no go. I tried the straw trick and pretty sure I saw no movement. I did take a video shown below but it was real difficult to hold her steady and what looks like movement in the vid wasnt apparent to me. I tried to keep my line of sight in line with top of straw and passenger fender.
Also, in diagnostic mode, no clicking is heard from the MCS.
UPLOADING VID NOW.
If I disconnect the 4 pin connector from the dizzy and put on a non computer carb, that would at least tell me if the actual carb was the problem wouldnt it?
If that was the case I could rebuild it.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
Hey guys.....
So I reconnected the PCV and the MAP sensor.
I plugged the headlight vac feed and the brake servo.
Still no go. I tried the straw trick and pretty sure I saw no movement. I did take a video shown below but it was real difficult to hold her steady and what looks like movement in the vid wasnt apparent to me. I tried to keep my line of sight in line with top of straw and passenger fender.
Also, in diagnostic mode, no clicking is heard from the MCS.
UPLOADING VID NOW.
If I disconnect the 4 pin connector from the dizzy and put on a non computer carb, that would at least tell me if the actual carb was the problem wouldnt it?
If that was the case I could rebuild it.
So I reconnected the PCV and the MAP sensor.
I plugged the headlight vac feed and the brake servo.
Still no go. I tried the straw trick and pretty sure I saw no movement. I did take a video shown below but it was real difficult to hold her steady and what looks like movement in the vid wasnt apparent to me. I tried to keep my line of sight in line with top of straw and passenger fender.
Also, in diagnostic mode, no clicking is heard from the MCS.
UPLOADING VID NOW.
If I disconnect the 4 pin connector from the dizzy and put on a non computer carb, that would at least tell me if the actual carb was the problem wouldnt it?
If that was the case I could rebuild it.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
Well the plugs are gone from the top of the carb. I forgot to look to see about the lower ports.....doh!
Forgot to mention, when I took the straws out of the carb...they had gas in them...thats not right is it?????
Forgot to mention, when I took the straws out of the carb...they had gas in them...thats not right is it?????
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
it crossed my mind but I never mentioned it.
a rebuild is a great idea.
you will need a tool. a tool I made from a drill bit.
find a bit that will fit in the access holes on top.
take a dremmel with a cut off wheel and make a slot in the shank
end of the bit to fit the adjuster head of the "bolt" in the hole.
try and get it centerline and whittle away slowly until it fits.
another thing that crossed my mind is the Ignition module.
it can make the engine act like you describe.
they can be tested at parts houses.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
I suggest you buy a rebuilt or new rather than rebuild unless you
can test the mix solenoid unit. why it isn't "clicking"
or bouncing the straw is a problem that a rebuild won't fix unless you get a new one.
then the tools and skillz to assemble come into it.
then there is the throttle position sensor poosibilty of being bad.
and needing adjusting.
can test the mix solenoid unit. why it isn't "clicking"
or bouncing the straw is a problem that a rebuild won't fix unless you get a new one.
then the tools and skillz to assemble come into it.
then there is the throttle position sensor poosibilty of being bad.
and needing adjusting.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
If I put it into diagnostic mode, Im guessing I should get some kind of voltage at the connector for the MCS.
I could check that to see if im getting a signal. I could also apply a voltage to the actual MCS to see if it clicks. This would then prove the wiring to be at issue.
Im guessing it uses the full 12 volts?
I could check that to see if im getting a signal. I could also apply a voltage to the actual MCS to see if it clicks. This would then prove the wiring to be at issue.
Im guessing it uses the full 12 volts?
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
If I put it into diagnostic mode, Im guessing I should get some kind of voltage at the connector for the MCS.
I could check that to see if im getting a signal. I could also apply a voltage to the actual MCS to see if it clicks. This would then prove the wiring to be at issue.
Im guessing it uses the full 12 volts?
I could check that to see if im getting a signal. I could also apply a voltage to the actual MCS to see if it clicks. This would then prove the wiring to be at issue.
Im guessing it uses the full 12 volts?
here is the testing
key on,
volt at sol test lead (green plug) and ground
over ten/ check voltage at ECM term, wire 18/ over 10 volts at ECM check sol resistance/ over 10 ohms faulty= ECM/ under 10ohms change sol and ECM
under 10 volts
put test light on the mix sol plug pink lead and ground.
light on/ put test light on both wires from plug (no volt meter)/
light off/check for open wire if no open-bad wire change mix sol.
light on/remove - unplug the "numbered plug" from ECM/ light off = bad ECM light ongrounded wire from mix sol to ECM term 18.
put test light on the mix sol plug pink lead and ground.
light off/ check for open wire in B+ circuit.
Racer
Joined: Mar 2003
Posts: 448
Likes: 21
From: Klein Texas
The solenoid is spring loaded with the mixture rods out of the jets (full rich).
If the solenoid had an open circuit, unplugged or failed computer driver; the carb would be running with your eyes watering and black smoke out the exhaust.
If you want to test, inset a small screw driver, pick, 16D nail or something similar into either hole just beside the idle air bleed circled in the picture above. You should be able, with a soft touch, feel the MC piece that pulses the mixture rods up and down. The up and down travel is usually close to 1/8 inch.
Form you symptoms, I think you're barking up the wrong tree.
If the solenoid had an open circuit, unplugged or failed computer driver; the carb would be running with your eyes watering and black smoke out the exhaust.
If you want to test, inset a small screw driver, pick, 16D nail or something similar into either hole just beside the idle air bleed circled in the picture above. You should be able, with a soft touch, feel the MC piece that pulses the mixture rods up and down. The up and down travel is usually close to 1/8 inch.
Form you symptoms, I think you're barking up the wrong tree.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
the resiatnce of the sol should be over 10ohms.
here is the testing
key on,
volt at sol test lead (green plug) and ground
over ten/ check voltage at ECM term, wire 18/ over 10 volts at ECM check sol resistance/ over 10 ohms faulty= ECM/ under 10ohms change sol and ECM
under 10 volts
put test light on the mix sol plug pink lead and ground.
light on/ put test light on both wires from plug (no volt meter)/
light off/check for open wire if no open-bad wire change mix sol.
light on/remove - unplug the "numbered plug" from ECM/ light off = bad ECM light ongrounded wire from mix sol to ECM term 18.
put test light on the mix sol plug pink lead and ground.
light off/ check for open wire in B+ circuit.
here is the testing
key on,
volt at sol test lead (green plug) and ground
over ten/ check voltage at ECM term, wire 18/ over 10 volts at ECM check sol resistance/ over 10 ohms faulty= ECM/ under 10ohms change sol and ECM
under 10 volts
put test light on the mix sol plug pink lead and ground.
light on/ put test light on both wires from plug (no volt meter)/
light off/check for open wire if no open-bad wire change mix sol.
light on/remove - unplug the "numbered plug" from ECM/ light off = bad ECM light ongrounded wire from mix sol to ECM term 18.
put test light on the mix sol plug pink lead and ground.
light off/ check for open wire in B+ circuit.
The solenoid is spring loaded with the mixture rods out of the jets (full rich).
If the solenoid had an open circuit, unplugged or failed computer driver; the carb would be running with your eyes watering and black smoke out the exhaust.
If you want to test, inset a small screw driver, pick, 16D nail or something similar into either hole just beside the idle air bleed circled in the picture above. You should be able, with a soft touch, feel the MC piece that pulses the mixture rods up and down. The up and down travel is usually close to 1/8 inch.
Form you symptoms, I think you're barking up the wrong tree.
If the solenoid had an open circuit, unplugged or failed computer driver; the carb would be running with your eyes watering and black smoke out the exhaust.
If you want to test, inset a small screw driver, pick, 16D nail or something similar into either hole just beside the idle air bleed circled in the picture above. You should be able, with a soft touch, feel the MC piece that pulses the mixture rods up and down. The up and down travel is usually close to 1/8 inch.
Form you symptoms, I think you're barking up the wrong tree.
Think I will pull gas filter as she had run out of gas and has gone through a gallon just testing. Might as well check the float and needle valve whilst I'm in there.
Racer
Joined: Mar 2003
Posts: 448
Likes: 21
From: Klein Texas
There are many good ideas in this thread just not a conclusive pathway.
Your symptoms sound like it is running out of fuel. Here's what I would do.
Without experience, I'd refrain from removing the top of the carb to check the float, needle seat. The TPS push rod is easy to lose and the TPS sensor needs to be held down with a thin machinist rule to get the top of the carb back on without breaking it.
Post up your results. I've rebuilt hundreds of those carbs with great success.
Your symptoms sound like it is running out of fuel. Here's what I would do.
- Jump the ALDL and check your trouble codes. There should only be code 12 for lack of RPM signal.
- Disconnect the fuel line from the carb and run it into a bucket. Make sure the pump dispenses plenty of fuel (a pint every 10 seconds or so). A cheap is handy. 5 p.s.i. would be typical. Make sure the fuel filter is new and installed in the correct direction.
- A install inline would give you an idea if the ignition coil, module or pickup coil is weak.
Without experience, I'd refrain from removing the top of the carb to check the float, needle seat. The TPS push rod is easy to lose and the TPS sensor needs to be held down with a thin machinist rule to get the top of the carb back on without breaking it.
Post up your results. I've rebuilt hundreds of those carbs with great success.
Thread Starter
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
OK, Ive got the code 12 and no others.
Will check the fuel delivery.
I have a vacuum gauge similar to the one shown. Didnt realise it can do pressure as well. Will have a look and try it.
Havent got a spark tester, may have to invest!
Ive rebuilt a couple of qjets before. Is there any major difference between the older ones and the comp one?
Will check the fuel delivery.
I have a vacuum gauge similar to the one shown. Didnt realise it can do pressure as well. Will have a look and try it.
Havent got a spark tester, may have to invest!
Ive rebuilt a couple of qjets before. Is there any major difference between the older ones and the comp one?
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
jotto:
I assume you do not have the 1981 Service Manual...?
send me a PM with your email address and I will scan and email a few pages about the E4ME carb to you that will tell you what you need to know.
I assume you do not have the 1981 Service Manual...?
send me a PM with your email address and I will scan and email a few pages about the E4ME carb to you that will tell you what you need to know.