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Tim's Auto Repair
Tim's Auto Repair, Mechanic
Category: Car
Satisfied Customers: 12808
Experience:  Have owned a repair shop for 25 yrs.
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I have a 96 k1500 with a completely rebuilt motor. 30 over

Customer Question

I have a 96 k1500 with a completely rebuilt motor. 30 over with an rv cam built by a certified engine builder. my problem is that at idle it wants to surge up and down, it hestitates on take off and in gear the surging becomes worse. after take off the engine seems to run smoothly thru entire speed range. is this a throttle body problem, throttle sensor and can they be cleaned as the body is expensive and i am just a shadetree mechanic, 57 and not that good ha! the mass air flow was replaced that was no help. thanks Ed
Submitted: 1 year ago.
Category: Car
Expert:  Tim's Auto Repair replied 1 year ago.

tims auto repair :

hi


 

tims auto repair :

does the engine light stay on?if so,can you give me the computer codes?


 

Customer:

no check engine light


 

Customer:

no service no answer

Customer:

your offline i have other things to do love to hear the answer ed

tims auto repair :

hi Ed


 

tims auto repair :

sorry i missed you


 

tims auto repair :

sense you get no trouble codes


 

tims auto repair :

this does sound as if you may have a bad trottle position sensor


 

tims auto repair :

this is located on the side of the throttle body


 

tims auto repair :

you may also want to remove and clean the iac with carb cleaner


 

tims auto repair :

this can,get dirty with black soot and cause a similer


 

tims auto repair :

problem


 

tims auto repair :




























1995 Chevy Truck C 3500 Truck 2WD V8-350 5.7L VIN K TBI
Throttle Position Sensor Service and Repair, Procedures: Throttle Position (TP) Sensor Replacement









66_gmtrkbar90-031.png
Full Size Image

Throttle Position (TP) Sensor





NOTE: Since TP configurations can be mounted interchangeably, be sure to order the correct one for your engine with the identical part number of the one being replaced.

REMOVE OR DISCONNECT
1. Electrical connector.
2. Two TP sensor attaching screw assemblies.
3. TP sensor from throttle body assembly.

NOTE: The TP sensor is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result.

INSTALL OR CONNECT
1. With throttle valve in normally closed position, install TP sensor on throttle shaft and rotate counter clockwise to align mounting hole.
2. TP sensor attaching screw assemblies, precoated with appropriate thread.locking compound. Tighten Screw assemblies to 2.0 Nm (18.0 lb. in.).
3. Electrical connector.
4. Check for TP sensor output as follows:
^ Connect scan tool scanner to read TP sensor output voltage.
^ With ignition "ON" and engine stopped, TP sensor voltage should be less than 0.85 volt. If more than 0.85 volt, replace TP sensor.


tims auto repair :





























1996 Chevy Truck Truck


V8-350 5.7L VIN K TBI


Idle Speed/Throttle Actuator - Electronic Service and Repair, Procedures: Idle Air Control (IAC) Valve Replacement









65_95ckbk2_4A-021b.png
Full Size Image

IAC Valve


 








64_95ckbk2_4A-022.png
Full Size Image

IAC Valve





NOTE: The IAC valve is an electrical component and must not be soaked in any liquid cleaner or solvent. Otherwise damage could result.

IMPORTANT: Thread-mounted IAC Valves have a dual taper, 10 mm diameter, pintle. The flange-mounted IAC valve and has a 12 mm diameter, dual taper pintle.

Any replacement of an IAC valve must have the correct part number, with the appropriate pintle taper and diameter for proper seating of the valve in the throttle body.

REMOVE OR DISCONNECT
1. Electrical connector.
2. IAC valve.
^ On thread-mounted units, use a 32 mm (1-1/4") wrench.
^ On flange-mounted units, remove screw assemblies.
3. IAC valve gasket or 0-ring and discard.

CLEAN
^ Thread-mounted valve - Old gasket material from surface of throttle body assembly to insure proper seal of new gasket.
^ Flange-mounted valve - IAC valve surface on throttle body to assure proper seal of new 0-ring and contact of IAC valve flange.

NOTE: If the IAC valve was removed during service, its operation may be tested electrically with the IAC system analyzer (J 37027 or BT- 8256K). However, if the valve pintle is extended electrically, it must also be retracted electrically. Before installing an IAC valve, measure the distance between the tip of the valve pintle and the mounting surface. If the dimension is greater than 28 mm (1.10"), it must be reduced to prevent damage to the valve. This may be done electrically using on IAC system analyzer motor tester (J 37027 or BT-8256K).

MEASURE
^ Distance between tip of IAC valve pintle and mounting flange.
- If greater than 28 mm, use finger pressure to slowly retract the pintle. The force required to retract the pintle of a new valve will not cause damage to the valve.

IMPORTANT: No physical adjustment of the IAC valve assembly is required after installation. The IAC valve pintle is reset by the control module system which causes the valve pintle to seat in the throttle body. The control module then has a reset procedure to set the correct pintle position. Proper idle regulation should result.

INSTALL OR CONNECT
1. IAC valve into throttle body as follows:
^ Thread-mounted valve - Install with new gasket.
^ Flange-mounted valve - Install with new lubricated 0-ring, using attaching screw assemblies. Tighten Thread-mounted IAC valve assembly to 18.0 Nm (13.0 lb. ft.) with 32 mm (1-1/4") wrench. Tighten Flange-mounted attaching screw assemblies to 3.2 Nm (28.0 lb. in.).

2. Electrical connector to IAC valve.
3. Reset IAC valve pintle position:
^ Remove battery cable for 10 seconds.
^ Ignition "ON," engine "OFF" for 5 seconds.
^ Ignition "OFF," for 10 seconds.

tims auto repair :

Please RATE my answer by clicking the RATINGS button, so I can get credit for my work,,the [BAD SERVICE] and [POOR SERVICE] rating does not give me credit].i don't receive commission if you give a less than 3 star/smiley rating ..I'm not always going to be giving you good news,so please don't let this stand in the way of you accepting my answer.it does not cost you more money.we will still be able to communicate,,.please understand,i can not see,hear or touch the vehicle and only know what you tell me. Bonuses and positive feedback are appreciated!if you are not satisfied with my answer,please do not leave bad feed back,i will gladly opt out and let another expert handle the question.if i have sent any diagrams,please print them.they will only stay on here for an hour or so...sometimes you may need to right click the image,then save picture as]to save it to your computer so you can open it with your picture program...PLEASE ASK IF YOU NEED MORE HELP


 

Tim's Auto Repair, Mechanic
Category: Car
Satisfied Customers: 12808
Experience: Have owned a repair shop for 25 yrs.
Tim's Auto Repair and 16 other Car Specialists are ready to help you

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