How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask AMEDEE Your Own Question

AMEDEE
AMEDEE, CHEVY TECHNICIAN
Category: Chevy
Satisfied Customers: 21883
Experience:  ASE MASTER TECHNICIAN ADVANCED LEVEL SPECIALIST. Wisconsin certified emissions state inspector
279429
Type Your Chevy Question Here...
AMEDEE is online now
A new question is answered every 9 seconds

1987 s10 wont start unless i pour gas down throttle body

Customer Question

No Comment Added
Submitted: 6 years ago.
Category: Chevy
Expert:  AMEDEE replied 6 years ago.
You could have a bad fuel pump. I would rec to check fuel pressure. Fuel injected cars are very fuel pressure sensitive. Fuel pressure is very important and must be within specifications! But if the pressure is low, it does not mean the pump is bad. A plugged fuel filter, a pinched line, and low voltage at the pump can contribute to low fuel pressure. All three must be check before replacing the pump! You can get a fuel pressure gage at a local auto parts store for cheap. Good luck!
Customer: replied 6 years ago.
fuel pressure good already have gage
Expert:  AMEDEE replied 6 years ago.

I would rec to check for fuel trigger. Fuel trigger is the signal from the computer to the injectors. You would use a tool called a noid light. It simply plugs into the injector connector after the fuel injector is unplugged and should blink when the engine is cranked over. It looks like this.

 

graphic

Customer: replied 6 years ago.
tried that with a regular test light no blink
Expert:  AMEDEE replied 6 years ago.
Did you test for a ground signal trigger?
Customer: replied 6 years ago.
truck only has one fuel injecotr, test with key on and tester on - side wire with power, take other wire and hook tester to + should flash when i crank it right that is what another expert said and then he told me it was the ecm so i repaced it no luck and tested again still no flash o yea also checked wire
Expert:  AMEDEE replied 6 years ago.
DO you have spark?
Customer: replied 6 years ago.
yes and thank you for being so fast so far i have used this 3 times and had to wait way too long
Expert:  AMEDEE replied 6 years ago.
Does the check engine light come on with the key in the on position?
Customer: replied 6 years ago.
yes it also will run if i pour gas in it not well but it will stuble untill it burns all the gas up
Expert:  AMEDEE replied 6 years ago.
Have you tested the pick up?
Customer: replied 6 years ago.
pick up? not shure what you mean
Expert:  AMEDEE replied 6 years ago.
Have you replaced the distributor?
Customer: replied 6 years ago.
not the whole thing but the cap rotor and modual get health spark. thing is it sat for 2 years ran when parked now dosent
Expert:  AMEDEE replied 6 years ago.

Well the pick up inside the distributor can be bad. This is what tells the computer that the engine is turning over and for the injectors to fire.

The distributor has a separate coil which connects to the rotor through a high tension wire.

The distributor uses a magnetic pick-up assembly located inside the distributor consists of a permanent magnet, a pole piece with internal teeth, pick-up coil, and a hall effect switch. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage of 35,000 volts is induced in the ignition coil secondary winding which is directed through the rotor and secondary leads to fire the spark plugs. This system incorporates a hall effect switch which tells the ECM when to fire the next cylinder. The capacitor in the distributor is for radio noise suppression.

This distributor also features a longer spark duration, made possible by the higher amount of energy that is stored in the coil. This is desirable for firing leaner mixtures

Customer: replied 6 years ago.
ok (trying not to sound stuipd) that part is called the distbutor pickup?
Expert:  AMEDEE replied 6 years ago.
You got it!
Customer: replied 6 years ago.
ok ill try that cross my fingers but cannot do untill tommaro, ill stay online and let you know tommaro is that doable
Expert:  AMEDEE replied 6 years ago.
Sounds good!
Customer: replied 6 years ago.
part dident come in to day somthing wrong with dilivery truck tomorrow for shure
Expert:  AMEDEE replied 6 years ago.

K... I will be here!

 

Customer: replied 6 years ago.
are you online
Customer: replied 6 years ago.
did the pickup and no change someone told me how to scan comp with paperclip and code 12 comes up and that is hall effect switch so ill go get that one now.
Customer: replied 6 years ago.
did more resurch and 12 is not hall effect switch, so i tested it according to haynes and i think it failed not shure if volage meter was on right setting had a friend stop by and crank truck wile i watched the for injector spray and there was noe at all
Expert:  AMEDEE replied 6 years ago.

Lets check for the ground signal trigger at the signal wire coming right out of the computer.

ALso, lets pull codes again

Expert:  AMEDEE replied 6 years ago.

graphic

 

This connector is used in the assembly plant to connect a computer for checking of the system to see that it is functioning properly before shipping the vehicle. To obtain trouble codes with the ignition switch on and the engine either stopped or running the "test" terminal in this connector should be grounded. The "test" terminal should be ungrounded when starting the engine or the "Check Engine" lamp will not function properly. Refer to Figure 1.

Expert:  AMEDEE replied 6 years ago.

ALso, here is a flow chart to help you diagnose the no injector pulse.

Circuit Description :

This chart should only be used if diagnosis in CHART A-3 indicated an injector circuit problem.

 

Test Description : Numbers below refer to circled numbers on the diagnostic chart.

This test will determine if the ignition module is generating a reference pulse, if the wiring is at fault or if the ECM is at fault. By touching and removing a test light, connected to 12 volts, to CKT 430, a reference pulse should be generated. If injector test light blinks, the ECM and wiring are OK.
This step tests for 12 volts to the injector. It will also determine if there is a short to voltage on the ECM side of the circuit.
This test checks for continuity to the ECM.

graphic

graphic

Customer: replied 6 years ago.
just got a distributor form another truck runs now but boy is it smokin white
Customer: replied 6 years ago.
smokin really bad even more when i geve it throttle any ideas why
Expert:  AMEDEE replied 6 years ago.
Where is the smoke coming from? Under the hood, or out the tail pipe?
Customer: replied 6 years ago.
was coming from tail pipe now is mostly gone but now that i let sit after i ran it and had no problem idling just smoking, now it wont idle and has a little blow back threw carb and wont start unless i give it throttle
Expert:  AMEDEE replied 6 years ago.
WHat did you set the ignition timing at?
Customer: replied 6 years ago.
says 8
Expert:  AMEDEE replied 6 years ago.
That should work as you as you followed directions and set the idle accordingly.
Customer: replied 6 years ago.
just went out to look at truck and it is leaking gas from that emmisons canistor on the drivers side front fender well what is that all about its quite a lot of fuel
Expert:  AMEDEE replied 6 years ago.
Did you overfill the tank with gas?

Did the gas get in there from when you where pouring fuel into the intake?
Customer: replied 6 years ago.
mabe if you think me not so shure because it dident leak untill i ran the motor makes no sence to me
Expert:  AMEDEE replied 6 years ago.
Try disconnecting it and see if that helps
Customer: replied 6 years ago.
gas must have been from me no more leak, still no idle runs ok just when you let off the gas completly it dies and also you cant ajust the idle speed on throttle body applications
Expert:  AMEDEE replied 6 years ago.
Have we checked for codes with the info I gave you?
Customer: replied 6 years ago.
no ill do can you explain how so i now im doin it right never messed with that befor today
Expert:  AMEDEE replied 6 years ago.
To obtain trouble codes with the ignition switch on and the engine either stopped or running the "test" terminal in this connector should be grounded. The "test" terminal should be ungrounded when starting the engine or the "Check Engine" lamp will not function properly. Refer to the diagram a few posts ago
Customer: replied 6 years ago.
did the test blinked 12 a bunch of times haynes says this code will flash every time teminal is grounded and will flash 3 times and then flash the the codes
Expert:  AMEDEE replied 6 years ago.
That is correct.

What code was flashed after code 12 was flashed three times?
Customer: replied 6 years ago.
nothing i watched code 12 flash probly 8 times
Expert:  AMEDEE replied 6 years ago.
SO we got it running, but it just wont idle?

Have we checked for vacuum leaks?
Customer: replied 6 years ago.
well the first time it ran it idled fine now it wont but still runs in no dont have a fancy vacume gauge yet is there another way
Expert:  AMEDEE replied 6 years ago.
This is very common! Open the hood and listen for a hissing sound when the engine is running.
Unmetered air can enter the engine through a vacuum leak, a dirty airflow sensor that is not reading airflow accurately, an EGR valve is not closing and is leaking exhaust into the intake manifold, an EGR valve that is allowing too much flow.
If it is hard to pinpoint take some brake cleaner or starting fluid around the intake manifold and vacuum lines and see if the engine stumbles or if the idle is affected. Be extremely careful when doing this!

Also, your throttle body may be carboned up and need to be cleaned! This can cause all sorts of idle and hesitation problems. This is caused by the throttle plate not seating properly. The First thing i would do is clean out the throttle body with some throttle plate and intake cleaner and a small brush. Another common cause would be the Idle Air Control motor. This is very common on older cars. The IAC motor gets lazy and cant keep up with the fast idle changes. Also when the IAC motor is out, I rec to check the passages for carbon build up. If they are plugged they need to be cleaned out.



Check for the following conditions:



Poor connection at PCM or IAC motor. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
Damaged harness. Inspect the wiring harness for damage.
Restricted air intake system. Check for a possible collapsed air intake duct, restricted air filter element, or foreign objects blocking the air intake system.
Throttle body. Check for objects blocking the IAC passage or throttle bore, excessive deposits in the IAC passage and on the IAC pintle, and excessive deposits in the throttle bore and on the throttle plate. Check for a sticking throttle plate. Also inspect the IAC passage for deposits or objects which will not allow the IAC pintle to fully extend.
Vacuum leak. Check for a condition that causes a vacuum leak, such as disconnected or damaged hoses, leaks at EGR valve and EGR pipe to intake manifold, leaks at throttle body, faulty or incorrectly installed PCV valve, leaks at intake manifold brake booster hose disconnected, oil filler cap, oil level indicator loose or missing, etc..
Customer: replied 6 years ago.
ok after cooled down truck started and idled great after setting timing again and idleing for while it started not idling gradualy after a shile i let truck die got out and there was a lot of gas on floor its coming out of cansitor from the line thats inbetween the two fuel lines also after seeing gas i thought i try the gas cap and there was quite a bit of pressure in the tank
Expert:  AMEDEE replied 6 years ago.
SI it is idling ok now?
Customer: replied 6 years ago.
unhooked that line to that canistor and everything ok but gas still coming out of the line when i put thte gas cap on im thinking stuck vent mabe
Expert:  AMEDEE replied 6 years ago.
Which line did you dissconnect from the canister? The line coming from the fuel tank?
Customer: replied 6 years ago.
yes
Expert:  AMEDEE replied 6 years ago.
Looks like you might have disconnected the one that comes from the manifold. This is most likely full of fuel because you were pouring gas down the throttle body to get it to start.
Here is a diagram.

graphic
Customer: replied 6 years ago.
right but it takes about 10 min of idling and gas is pouring out of that disconected line just like it is the supply line
Expert:  AMEDEE replied 6 years ago.
Well then disconnect it from the manifold and plug up the vacuum leak.
Customer: replied 6 years ago.
but i would like to fix the problem probly get the better gas milage with the canistor and today that is important
Expert:  AMEDEE replied 6 years ago.
Well, that is another question.

I have answered your first question and many more and got your truck running. And have put a lot of time into helping you and I have not gotten an accept from you yet.

I will opt out so another expert can assist you. I am done giving you free information.

You can re list with another question.

Have a good day.
Customer: replied 6 years ago.
no problem get right on that

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
< Last | Next >
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
< Last | Next >
  • http://ww2.justanswer.com/uploads/TI/tim37857/2011-10-28_23053_S6301814.64x64.JPG Tim's Auto Repair's Avatar

    Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
  • http://ww2.justanswer.com/uploads/DT/dt69nova/2012-6-15_234154_pic1.64x64.jpg Dave Nova's Avatar

    Dave Nova

    Chevrolet Technician

    Satisfied Customers:

    6870
    ASE Master Certification. GM World Class Certification
  • http://ww2.justanswer.com/uploads/ggrote1/2009-06-27_031011_me.jpg Gary's Avatar

    Gary

    Chevy Technician

    Satisfied Customers:

    5404
    15 years GM master tech
  • http://ww2.justanswer.com/uploads/testedtuff/2009-09-26_170108_pictures.jpg John's Avatar

    John

    Master A.S.E Automotive technician

    Satisfied Customers:

    4071
    A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
  • http://ww2.justanswer.com/uploads/RO/rodcuda/2011-7-25_224114_Donhoff1.64x64.JPG Neal's Avatar

    Neal

    Chevy Mechanic

    Satisfied Customers:

    2306
    Shop Owner and Mechanic on multiple makes.
  • http://ww2.justanswer.com/uploads/goodwrench9124/2008-11-09_220838_dscf0007.jpg goodwrench9124's Avatar

    goodwrench9124

    ASE Certified Technician

    Satisfied Customers:

    2041
    Ase Master Certified, GM Master Certified Tech. Awarded GM Top performer, Hybrid certified
  • http://ww2.justanswer.com/uploads/DR/drivefast1971/2012-1-12_172422_0009051tQKh.64x64.jpg Ron Z.'s Avatar

    Ron Z.

    - Chevy Tech -

    Satisfied Customers:

    1912
    18+yrs experience. State Inspector and Chevy Diagnostics