Question about 1989 Chevrolet C1500

1 Answer

Instantanious ignition drop out

89 Chevy 1500 truck / 350ci engine /throttle body fuel injection/ with automatic transmission.Problem; Instantanious intermitant inigtion drop out, just as you could create by switching off key and instantly turning key back on. Problem is narrowed down to speed sensor circuit on transmission tail section. Yes, I know , it makes no sense. Unplug speed sensor, engine runs perfect.Replaced speed sensor / no change, ran out circuit all the way to instrument cluster no wire damage found.Removed cluster from dash, engine runs perfect/replaced with new cluster, no change. Ran out circuit to ECM module ,no wire damage found.Replaced ECM module, no change.Coil,complete distibutor,rotor, wires, plugs,etc.etc. all replaced with new known good parts. NO change ,Unplug speed sensor at transmission and engine runs perfect(speedo nolonger works with sensor unplugged of course)plug sensor back in and engine imediately starts dropping out and in. This is a must find & fix ,you cant turn loose a teenager in a vehicle with no speedometer. At this point I am out of Ideas.

Posted by on

  • carhob May 11, 2010

    a stab in the dark here! pre 91 models vss sensor signal helped control tcc of tranny thru ecm,maybe tcc goes haywire locks and unlocks bogging down engine,just an idea!

×

1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    Hot-Shot:

    An expert who has answered 20 questions.

    Corporal:

    An expert that hasĀ over 10 points.

    Mayor:

    An expert whose answer gotĀ voted for 2 times.

  • Expert
  • 50 Answers

Chek for good engine graund ,inspeckt body graund to.bed graunds on motor and bady will cose lat of hedicks

Posted on Mar 13, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

5 Answers

2002 van 1500, 5.7 engine. Why won't it start?


Throttle body injection I assume , watch butterfly on injector and c if it injects fuel , if it starts w ether but shuts off its still not getting fuel into cylenders and since your fuel pressure to engine is normal , the problem is in the throttle body or injection ..possible electrical ...if for some reason u still have a carbureted engine hit me back up it could be sumin diff

Nov 13, 2015 | GMC Sierra 1500 Cars & Trucks

1 Answer

Where is the speed sensor at on a chevy z71 1994 4x4 truck


I think you made a big mistake throttle body fuel injection that you removed is much much more superior to any carburetor that's on the market, what were you thinking. I imagine when you put the carburetor on you did not reattach the throttle positioning sensor. Your engine control module needs the information from your throttle positioning sensor. You might try to have the problem chip in your ECM reprogram. And what are you doing about a fuel pump, the carburetor runs on 5 to 7 pounds of pressure, your fuel pump spreading around 30 pounds, and the fuel regulator with in the throttle body. the best advice, is to reinstall the throttle body, before you cause a permanent damage to other systems on the vehicle.

May 04, 2014 | 1994 Chevrolet C1500

1 Answer

I have a 1990 Chevy 1500. Have replaced fuel-pump already and it ran great. Now it wont start again. Fuel-pump works, but injectors in throttle-body not injecting fuel. What would cause this?


Leak in fuel line. Put air pressure gauge on rail and crank engine. Should get psi reading. There should be a nipple on fuel rail for testing. If no pressure check for leak

Dec 28, 2012 | Cars & Trucks

1 Answer

Problems shifting into overdrive in my 96 chevy 1500 4x4


i have a 90 chevy 2500 2wd 350ci.when i go to start my truck the key turns hard in the ignition,the check engine light and brake light come on the heater dont work,and the transmission will shift from 1-2 at real high rpm and shift hard,no 3-od.this comes and goes,but all happens at the same time.some times it last for 10 min,sometimes its days.what is going on?

Apr 24, 2012 | 1996 Chevrolet K1500

1 Answer

How do you increase the idle speed on a 200 chevy silverado 1500 fuel injection 4.8 LT


the computer decides idle speed. take the big air hose off that goes from the air cleaner to the engine and clean the throttle body with carb cleaner and a toothbrush,open the throttle to clean it good. you may have to turn key on and depress the gas pedal.

Sep 22, 2011 | 2001 Chevrolet Silverado 1500

3 Answers

How do I know if my truck has a carb or if it's fuel injection?


FUEL INJECTION THROTTLE BODY INJECTION SYSTEM HAS TWO ROUND FUEL INJECTORS ON TOP.CARBURETOR DONT HAVE FUEL INJECTORS.IT HAS CHOKE VALVE AND FUEL NOZZLE WHICH IS THE FUEL METERING SYSTEM.

Feb 04, 2011 | 1987 Nissan Pickup

2 Answers

1990 chevy blazer 350 ci throttle body fuel injected . the motor is flooding out u can see the injectors keep dumping fuel into the throttle body


Sounds like you have an injector leaking. Have someone just cycle the key on and off to run the fuel pump but don't crank the engine. If you see fuel dripping from the injectors, unbolt the injector cover on the throttle body, remove the injectors and replace the orings around the injectors.

Jul 22, 2010 | 1991 Chevrolet C1500

1 Answer

Where are the throttle body plates located


Throttle plates are in your throttle body that open and close to allow more air into intake, Depending on fuel system- multi port fuel injection, Throttle body or carburated. In your case it is fuel injected.

Oct 07, 2009 | 2003 Chevrolet Silverado 1500

2 Answers

Engine power loss


Inspect Wireset Damaged, worn, or deteriorating spark plug or coil wire(s). in this list u will find a answer to ur problem Shaun 2 Inspect Spark Plug Fouled, damaged or broken spark plug(s). 3 Inspect Fuel Filter Clogged or dirty fuel filter 4 Inspect Distributor Worn, loose or incorrectly adjusted distributor. 5 Inspect Distributor Cap Loose or cracked distributor cap 6 Inspect Distributor Cap And Rotor Kit Loose, cracked, or worn distributor cap and ignition rotor. grey_line.gif 7 Inspect PCV Valve Plugged or damaged pcv valve. grey_line.gif 8 Inspect Air Filter Restricted or clogged air filter. grey_line.gif 9 Inspect Catalytic Converter Clogged, damaged, defective or faulty catalytic converter. grey_line.gif 10 Inspect Automatic Transmission Improperly adjusted kickdown cable adjustment or internal transmission problems. grey_line.gif 11 Inspect Fuel Pump Improperly functioning fuel pump or circuits. grey_line.gif 12 Inspect MAP Sensor Improperly connected or faulty m.a.p. sensor. grey_line.gif 13 Inspect Mass Air Flow Sensor Improperly connected or faulty mass air flow sensor. grey_line.gif 14 Inspect Throttle Position Sensor Faulty throttle position sensor or throttle position sensor circuit. grey_line.gif 15 Inspect Timing Specification Incorrectly adjusted engine timing. grey_line.gif 16 Inspect Fuel System Pressure Incorrect fuel pressure being delivered to carburetor or fuel injection system. grey_line.gif

Nov 13, 2008 | 2002 Chevrolet S-10

Not finding what you are looking for?
Cars & Trucks Logo

263 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

yadayada
yadayada

Level 3 Expert

61037 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

21949 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

6812 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...