Bad Idle and will die after many parts and trys

[pawman]

93 K1500 one owner with 150k. Love the truck but has had issue at idle. slight miss and will die at a light etc. Runs Great other than idle makes me think plugs are of.
Prev-owner replaced plugs/rotor/dist cap.
I decided to replace much under hood as this is my daily driver now including
Idle Control valve
throttle control sensor
MAP and the vac line to it
MAP control... where MAP vac line terminates
EGR valve and vac line
Both Fuel injectors after they failed a test.
Also adjusted timing(wire disconnected)
Did the procedure to drain ICU to reset
What would be left? Should the TBI base be rebuilt? Could a gasket on it be the issue?
Trying hard not to have to leave at a shop a week to get looked at so any ideas??
Surely not related but temp sender di not seem to be registering correct and went out today to no reading

 

[docstoy]

How long and or how many miles since this was done ? After IAC was a relearn performed ? Is plug for Minimum idle rate screw removed ? What is IAC counts at hot idle in gear ? Have you downloaded service manual from sticky thread above that is titled 88-98 service manuals, look for fuel and emissions manual, look at symptoms and go from there in service manual. Hope this helps, let us know

 

[Schurkey]

93 K1500

WHAT ENGINE???

has had issue at idle. slight miss and will die at a light etc. Runs Great other than idle

Vacuum leaks (air leak into manifold vacuum) are worst at idle, become less important as the throttle opens.

Have you looked at the magnet on the distributor shaft? They're often broken.

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makes me think plugs are of.

"Of" what?

Prev-owner replaced plugs/rotor/dist cap.

How long ago? How many miles?

I decided to replace much under hood as this is my daily driver now including
Idle Control valve
throttle control sensor
MAP and the vac line to it
MAP control... where MAP vac line terminates
EGR valve and vac line

What diagnosis was done before replacing these parts?

What is a "MAP control"?

Did you check the EGR solenoid? Are the EGR hoses connected properly?

Both Fuel injectors after they failed a test.

WHAT test?

Did the procedure to drain ICU to reset

WHAT procedure? WHAT is an ICU?

What would be left?

More than I have time to type.

Should the TBI base be rebuilt?

Does it need rebuilding?

Could a gasket on it be the issue?

Yes, it "could" be. The trick is figuring out which one(s).

any ideas??

Perform a cranking compression test on each cylinder.

Verify spark plug wires.

Replace O2 sensor. A 3-wire heated sensor is recommended, but even an original-replacement one-wire sensor would be acceptable.

Connect a scan tool, verify EVERY sensor and computer output.

Surely not related but temp sender di not seem to be registering correct and went out today to no reading

So the instrument cluster temp gauge doesn't work? Coolant level good? Wire still connected to the sending unit?

 

[pawman]

I am going to do the idle reset procedure with a paper clip. port A and B ,, then throw salt over my should and hopp backwards on one foot. hope it works

 

[pawman]

How long and or how many miles since this was done ? After IAC was a relearn performed ? Is plug for Minimum idle rate screw removed ? What is IAC counts at hot idle in gear ? Have you downloaded service manual from sticky thread above that is titled 88-98 service manuals, look for fuel and emissions manual, look at symptoms and go from there in service manual. Hope this helps, let us know

just reading on the reset but thanks.. doing it in the morning but just looked and the access to it has never been breached.. Would that mean it is factory set now and leave it

 

[pawman]

WHAT ENGINE???


Vacuum leaks (air leak into manifold vacuum) are worst at idle, become less important as the throttle opens.

Have you looked at the magnet on the distributor shaft? They're often broken.

You must be registered for see images attach

You must be registered for see images attach

"Of" what?


How long ago? How many miles?


What diagnosis was done before replacing these parts?

What is a "MAP control"?

Did you check the EGR solenoid? Are the EGR hoses connected properly?


WHAT test?


WHAT procedure? WHAT is an ICU?


More than I have time to type.


Does it need rebuilding?


Yes, it "could" be. The trick is figuring out which one(s).


Perform a cranking compression test on each cylinder.

Verify spark plug wires.

Replace O2 sensor. A 3-wire heated sensor is recommended, but even an original-replacement one-wire sensor would be acceptable.

Connect a scan tool, verify EVERY sensor and computer output.


So the instrument cluster temp gauge doesn't work? Coolant level good? Wire still connected to the sending unit?

yes just gauge.. Actually runs cooler than I expect so gonna get a new one and go from there. Don't mind these kind of parts so I know what I have

 

[pawman]

WHAT ENGINE???


Vacuum leaks (air leak into manifold vacuum) are worst at idle, become less important as the throttle opens.

Have you looked at the magnet on the distributor shaft? They're often broken.

You must be registered for see images attach

You must be registered for see images attach

"Of" what?


How long ago? How many miles?


What diagnosis was done before replacing these parts?

What is a "MAP control"?

Did you check the EGR solenoid? Are the EGR hoses connected properly?


WHAT test?


WHAT procedure? WHAT is an ICU?


More than I have time to type.


Does it need rebuilding?


Yes, it "could" be. The trick is figuring out which one(s).


Perform a cranking compression test on each cylinder.

Verify spark plug wires.

Replace O2 sensor. A 3-wire heated sensor is recommended, but even an original-replacement one-wire sensor would be acceptable.

Connect a scan tool, verify EVERY sensor and computer output.


So the instrument cluster temp gauge doesn't work? Coolant level good? Wire still connected to the sending unit?

andyes coolant level good. If it runs great at all other times but Idle would not the plugs and 02 be ok. I am not sure and asking

 

[pawman]

andyes coolant level good. If it runs great at all other times but Idle would not the plugs and 02 be ok. I am not sure and asking

it's a 350. I did replace 2 vac lines.. And did an old time check by spraying around other hoses and no extra stumble. May just do the O2 as well. It is in really good shape but bet it has never been replaced

 

[pawman]

WHAT ENGINE???


Vacuum leaks (air leak into manifold vacuum) are worst at idle, become less important as the throttle opens.

Have you looked at the magnet on the distributor shaft? They're often broken.

You must be registered for see images attach

You must be registered for see images attach

"Of" what?


How long ago? How many miles?


What diagnosis was done before replacing these parts?

What is a "MAP control"?

Did you check the EGR solenoid? Are the EGR hoses connected properly?


WHAT test?


WHAT procedure? WHAT is an ICU?


More than I have time to type.


Does it need rebuilding?


Yes, it "could" be. The trick is figuring out which one(s).


Perform a cranking compression test on each cylinder.

Verify spark plug wires.

Replace O2 sensor. A 3-wire heated sensor is recommended, but even an original-replacement one-wire sensor would be acceptable.

Connect a scan tool, verify EVERY sensor and computer output.


So the instrument cluster temp gauge doesn't work? Coolant level good? Wire still connected to the sending unit?

I see more questions for me than I can answer. I promise if I knew them all I would lay out as technical of an answer as I could. I may have misunderstood what the forum was for. Thanks for some good things to look at from here and I am making notes and a list. hoping at this point idle control reset will do it since I have not done that since replacing it

just reading on the reset but thanks.. doing it in the morning but just looked and the access to it has never been breached.. Would that mean it is factory set now and leave it

the plug is still over the idle screw. should I just leave it be

 

[docstoy]

If plug for minimum idle rate has not been removed , leave it alone because that's good , you won't have to chase iac counts,tps settings , glad your reading manuals, they will help you along. Keep us informed about progress and we will try to be of assistance if needed. Good luck