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: 25636
Experience:  ASE certified tech 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

My 1994 k3500 5.7 liter w manual trans has issues firing up,

Customer Question

My 1994 k3500 5.7 liter w manual trans has issues firing up
JA: What is the model of your '94 Chevy?
Customer: K3500
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: Replaced distributor, engine grounds, spark plugs and plug wires
JA: Have you checked all the fuses? Do you have a wiring diagram?
Customer: I have checked all fuses
JA: Anything else you want the mechanic to know before I connect you?
Customer: It is getting fuel, just not wanting to fire up
Submitted: 4 months ago.
Category: Chevy
Expert:  AMEDEE replied 4 months ago.

Hello and welcome!

My name isCustomerand I can assist you with your question.

Expert:  AMEDEE replied 4 months ago.

I will try my best to answer all of your questions.

However, before we get started, please let me mention a few things.

1. If at any point you would like to speak on the phone, please feel free to request a phone call on your end and I can call you right away.

2. If you dont understand any technical terms or anything that I mention (component tests or theory or operation), please let me know and I will provide you with a more in debt explanation or answer.

3. Please understand that I am here to help you anyway I can.

Your saying the engine cranks over but starts hard or does not start? Is that correct?

Does this happen all of the time or just when cold/warm?

Customer: replied 4 months ago.
It spins over fine, just doesnt fire up, doesnt seem to matter what the weather is
Expert:  AMEDEE replied 4 months ago.

Thank you for that information.

Have you checked for spark when this occurs?

Is the check engine light on? Are there any codes in the computer?

Have you checked the fuel pressure when this occurs?

Customer: replied 4 months ago.
I have checked for spark, it is orange, have not checked fuel pressure, but it wont fire up with starter fluid either
Customer: replied 4 months ago.
I have hooked up a scantool, no diagnostic codes are present,but scantool also shows tps @ .37 volts
Expert:  AMEDEE replied 4 months ago.

Ok so it sounds like there are a few things that need to be addressed..

The fuel pump could be bad.. and this is VERY common on these vehicles. This would need to be at least checked and or ruled out first.

The TPS signal voltage is a bit low as well. You might want to double check this signal and replace the TPS as needed.

You are going to want to check the primary ignition system and secondary ignition system along with checking for power at the ignition coil with the key on and cranking when this happens to ensure we dont have low voltage causing this orange spark.

Also, checking injector pulse using a noid light would be a good idea as well.

Customer: replied 4 months ago.
The fuel pump and relay are fully operational, but my scantool shows 0.0volts at fuel pump
The truck made a*****just a week ago without any issue, no service engine light came on, the pink wire from under the steering column ign switch has 12v with key on
Expert:  AMEDEE replied 4 months ago.

If there is no power to the fuel pump, the fuel pump will not work and the engine will not run.

I would recommend to check for power on the power supply wire going to the fuel pump just to be sure your reading is accurate.

If so, power up this wire manually and see if the engine will start and run.

If so, we can pull a wiring diagram of the fuel pump circuit and trace down the root cause of the power loss issue..

Expert:  AMEDEE replied 4 months ago.

Would you like a wiring diagram of the fuel pump circuit?

Customer: replied 4 months ago.
The fuel pump and relay are fully operational,and are sprayin fuel from the injectors when the key is turned on
Expert:  AMEDEE replied 4 months ago.

Excellent!

What is the fuel pressure at?

Customer: replied 4 months ago.
Tbi systems do not have a scrader valve to install a fuel pressure guage on, it does not fire up with starting fluid sprayed down the throttle bores
Expert:  AMEDEE replied 4 months ago.

You can hook up a fuel pressure gauge in line between the throttle body and fuel pressure line. I have done it more times that I would like to admit.

IF you dont think it is a fuel related issue, then you would need to check spark when cranking to ensure it is night blue and it can jump a half of an inch of a gap.

Customer: replied 4 months ago.
The spark is orange, and is not very conaistant
Expert:  AMEDEE replied 4 months ago.

Based on my experience, I dont think this is the issue.

But if you would like to persue it, then you need to check the ignition coil/module and power to the primary ignition system.

Expert:  AMEDEE replied 4 months ago.

Maybe we could talk on the phone? It might be easier that way..

Customer: replied 4 months ago.
Coil and module are new
Expert:  AMEDEE replied 4 months ago.

Does not matter. I have seen bad new parts right out of the box. In fact, just had a customer with this problem. Bad new part.

Customer: replied 4 months ago.
It had been fired up and running since i installed the new distributor and coil, seems like it gets fire when i first spin it over, then it weakens, possible ignition switch?
Expert:  AMEDEE replied 4 months ago.

YES Sir! That is possible! If the ignition switch were faulty, the ignition coil/module would have low voltage, so your going to want to check this and verify this is the case before replacing the ignition switch.

Expert:  AMEDEE replied 4 months ago.

I am glad I can help!

It has been a pleasure working with you. Please dont forget to honor your good faith deposit by rating my answer as "5 STAR SERVICE" for assisting you today.

Keep in mind, we can still continue this conversation at no further cost to you even after you rate my answer. Just reply back to me using this page and I will get it and get back to you ASAP!

Also, if you are a member or if you have a subscription to the site, you still need to rate my answer in order for me to get credit for assisting you with your question.

Please let me know if you have any further questions.

Expert:  AMEDEE replied 4 months ago.

Hello!

It'sCustomerand I just wanted to check in to see how things are going and to see if you need any further assistance?

Let me know!

Related Chevy Questions