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240 Need Help K-Jet CIS Poor Idle

D

dobber13

Member
Joined
Nov 16, 2002
Location
elgin s.c. 29045
Is there someone in or around Columbia S.C. surrounding area that would be able to look at a problem I have. Running lean (I think) and I have tried and tested everything and haven't been able to figure out what is causing it. At Idle it pops out the exhaust as if it is missing but it's not electrical since I have ruled that out.I have gone through everything at least twice and no I can't find any vacuum leak. Parts I have changed fuel pump,intank pump and temp.sensor, 02sensor and cleaned CPR, fuel distributor and frequency valve, new air filter,fuel filter, intake manifold gasket,throttle body gasket,ACV hoses,intercooler hoses,all vac. lines.Tested fuel delivery,system pressure 80psi,control pressure 25 cold warm up 50psi ,rest pressure good. Compression 1.155 2.155 3.155 and 4.155 ,new plugs,wires,distributor cap, hall sensor and rotor.
This work has been over the last 1 1/2 years. Had alot of support from T.Ber's but couldn't find the problem. At this point another set of eye's on it would help.
 
Last edited:
dobber13 said:
frequency valve.
Click to expand...

Although not your year, this manual may assist, if you can find an automotive dwell meter.

>Running lean (I think)

What happens when accelerator pedal is engaged fully from a stop? If driving in first gear at a higher RPM, what happens when throttle is released, with engine cold and at temp?
 
Have you set CO?
Does it idle without stalling?
Can you hear the frequency valve buzzing?
How does it drive otherwise?
Any problem starting?
What kind of popping out the exhaust? Like a chuffing sound?
 
gashog said:
Have you set CO?
Does it idle without stalling?
Can you hear the frequency valve buzzing?
How does it drive otherwise?
Any problem starting?
What kind of popping out the exhaust? Like a chuffing sound?
Click to expand...

CO yes
Idle's O.K but has a miss popping out the exhaust.
Frequency valve buzzing.
Drives good but you can feel the missing,under boost I can't tell if it's missing and boost is good. light throttle it will buck a little.
No starting problem cold or hot.
Chuffing? you can hear the popping well back at the exhaust. When the car warms up it does it more.

I borrowed a AFR and set at 14.7, when idling it would bounce from 14.1 to 14.9. Shut of engine disconnect 02 start up and it should be rock steady but it still bouncing about 14.3 to 14.7.
 
The ignition distributor should have been a PM generator :slash: VR type. Did you upgrade the ignition system or are you calling the stock pickup a hall effect sensor? Just want to be clear.

The harmonic damper, you probably know, likes to walk around after 30 years ish.
Your base ignition timing is dependent on the crank pulley timing mark.
Have you verified that this mark is actual TDC?

Kinda unlikely but a sticky valve or a broken valve spring might not repeatably show up on a compression test.
An intermittent hanging exhaust valve could manifest its self in the symptoms you described up top.

Have you checked frequency valve dwell?
Also, how did you set CO? Do you have a sniffer?
 
From what I have seen on this 244, it's mint. Everything under the hood is new. All sensors and the wiring harness are new. The engine has been rebuilt. Wait for the video. Photobucket is still down.
 
gashog said:
The ignition distributor should have been a PM generator :slash: VR type. Did you upgrade the ignition system or are you calling the stock pickup a hall effect sensor? Just want to be clear.

The harmonic damper, you probably know, likes to walk around after 30 years ish.
Your base ignition timing is dependent on the crank pulley timing mark.
Have you verified that this mark is actual TDC?

Kinda unlikely but a sticky valve or a broken valve spring might not repeatably show up on a compression test.
An intermittent hanging exhaust valve could manifest its self in the symptoms you described up top.

Have you checked frequency valve dwell?
Also, how did you set CO? Do you have a sniffer?
Click to expand...

I have had this on going problem for about 5 yrs. I have rebuilt this engine about 1 1/2 yrs. ago. I had another engine in the car while rebuilding mine and it did the same thing. So it's not any problem with the head.

Harmonic balance,not on a B21ft.

Hall Effect Sensor,same stock distributor.

CO don't have a sniffer.
 
dobber13 said:
I have had this on going problem for about 5 yrs. I have rebuilt this engine about 1 1/2 yrs. ago. I had another engine in the car while rebuilding mine and it did the same thing. So it's not any problem with the head.

Harmonic balance,not on a B21ft.

Hall Effect Sensor,same stock distributor.

CO don't have a sniffer.
Click to expand...
Yup disregard that. I just looked at one I have one on a stand. No rubber damper ring to rot.

Since you don't have a sniffer, you could set the CO screw with a dwell meter. You can pretty much do it by ear also, listening to the buzz of the frequency valve. You should hear it switch from lean to rich and back, once it's in closed loop. If it's switching evenly and not spending more time rich as opposed to lean, you're there.

The ignition on these cars is not great. The stock distributor has a magnetic VR pickup, not a Hall sensor.
IMO the hall sensor is a better system but the distributor lacks mechanical advance.
The stock ignition box is just a big module/amp.
You could replace it with an old MSD and Blaster.
That would rule out the switching side and increase your spark energy at the same time.

Why do you think it's lean?
And what is your base timing? I always run mine with a lot more advance then stock.
 
gashog said:
Yup disregard that. I just looked at one I have one on a stand. No rubber damper ring to rot.

Since you don't have a sniffer, you could set the CO screw with a dwell meter. You can pretty much do it by ear also, listening to the buzz of the frequency valve. You should hear it switch from lean to rich and back, once it's in closed loop. If it's switching evenly and not spending more time rich as opposed to lean, you're there.

The ignition on these cars is not great. The stock distributor has a magnetic VR pickup, not a Hall sensor.
IMO the hall sensor is a better system but the distributor lacks mechanical advance.
The stock ignition box is just a big module/amp.
You could replace it with an old MSD and Blaster.
That would rule out the switching side and increase your spark energy at the same time.

Why do you think it's lean?
And what is your base timing? I always run mine with a lot more advance then stock.
Click to expand...

A friend of mine helped with a video but is having a problem with photo bucket.As soon as photo bucket comes back up he will load it on my post.
I have the breakerless ignition system and I meant a new impulse sender.
My timing is set at 12 degree's,what are you running it at and why.
I have set the dwell with a meter and the dwell swings between 39 and 44 degree's. I have tried setting it by ear with out the 02 hooked up and it idle's smooth without popping out the exhaust but it seems like it is running a little rich.
 
dobber13 said:
A friend of mine helped with a video but is having a problem with photo bucket.As soon as photo bucket comes back up he will load it on my post.
I have the breakerless ignition system and I meant a new impulse sender.
My timing is set at 12 degree's,what are you running it at and why.
I have set the dwell with a meter and the dwell swings between 39 and 44 degree's. I have tried setting it by ear with out the 02 hooked up and it idle's smooth without popping out the exhaust but it seems like it is running a little rich.
Click to expand...

I run up to 30* advance depending on cam.
To do that, I brake off or bend the timing retard on the advance/retard servo to give a few more degrees of boost retard.
Also I run only 93 or better octane in KJet turbos.

If it's switching between rich and lean, then it's at stoic....or as close as Lambda Sond can get.
This is the problem with KJet. You can set it to factory spec and it'll run smoothly and reliably.
It winds up being so dam infuriatingly slow, you can't leave it.
So then you adjust and adjust untill you have a car that won't start when cold, stalls at traffic lights but will do a 45mph one wheel peel. :e-shrug:
 
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