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Tool Hut
Tool Hut, ASE Certified Technician
Category: Chevy
Satisfied Customers: 494
Experience:  Owner of a mobile diagnostics company assisting auto technicians with difficult vehicles
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Swapped a 97 vortec 5.7 plus it's harness to a 96 truck, it

Customer Question

swapped a 97 vortec 5.7 plus it's harness to a 96 truck, it cranks over but will not run.. it ran in the 97 though..
Submitted: 1 year ago.
Category: Chevy
Customer: replied 1 year ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  Tool Hut replied 1 year ago.

Hi, My Name is***** have over 20 years experience repairing vehicles. I am a ASE Certified Master Auto Technician. I am confident we can resolve your problem together.Please remember I don't know your skill level. I can't see, smell, hear, or touch the vehicle. It may take a few back and forth replies to get to a satisfactory resoloution. I also do not work in an office at just answer awaiting your reply. I operate a small business and will do my best to answer quickly. Depending on the day and time there may be a delay in getting back to you.Try your best to respond with good detail so I can do the same. I also try to give all of the information you may need expecting a positive rating. If there is any reason I cannot get a positive rating please let me know.

Do you know if it is missing spark or fuel? Does it have a security light on?

Customer: replied 1 year ago.
no security light on.. what I did just find was that the pink wire going to the ecm and coil are grounding out.. ūüėě explains the weak spark..
Customer: replied 1 year ago.
or is the pink supposed to be ground..
Expert:  Tool Hut replied 1 year ago.

Which pink wire? When is it ground?

Customer: replied 1 year ago.
there is a pink wire that seems to run throughout the ignition system. i did a continuity test to ground.. and it makes contact to ground.. I don't think it's supposed to..
Expert:  Tool Hut replied 1 year ago.

The coil should have 2 pink wires. Both should be power the white wire is trigger. SO when testing the key should be on and engine off.

Expert:  Tool Hut replied 1 year ago.

here is a diagram

Customer: replied 1 year ago.
I'm testing while key is off. its a hot wire, it shouldn't be grounded
Expert:  Tool Hut replied 1 year ago.

key off it will be. Thats how it shuts it off

Customer: replied 1 year ago.
it goes to an open circuit when off
Customer: replied 1 year ago.
I've never seen a live circuit ground out when not in operation.. but I'm just speaking of years of electrical tecnicianing.. this is a new one for me..so let's say it supposed to be grounded when off. what should I check,for?
Expert:  Tool Hut replied 1 year ago.

Only be concerned with what it has key on. You say it has weak spark? How did you determine that?

Customer: replied 1 year ago.
no spark to plug from distributor.. but, spark to plug if you hook a wire directly to coil and grounded, except the spark is a full orange and it only allows a spark to happen when the spark gap is small..
Expert:  Tool Hut replied 1 year ago.

The pink wire should be battery voltage

Customer: replied 1 year ago.
it's 12.25 the battery is 12.5
Expert:  Tool Hut replied 1 year ago.

That should be sufficient. Did the distributor come out of truck or engine?

Customer: replied 1 year ago.
i replaced it.. tdc on cylinder 1 with valve cover off to make sure both valves were closed, then distributor installed to where the rotor is pointing to cylinder 1 on cap
Expert:  Tool Hut replied 1 year ago.

Is it possible it is 180 degrees off? Which valve was next to open when you rolled over?

Customer: replied 1 year ago.
I'm very sure that it's on the money.. checked over 6 times..just in case I did do 180 out .. that's why I removed valve cover..
Expert:  Tool Hut replied 1 year ago.

So when you roll the engine with distributor pointing to 1 which valve is next to open?

Customer: replied 1 year ago.
I don't know.. that's a different way that I've never done.. it should be 8 I suppose
Customer: replied 1 year ago.
all I know is I aligned the timing cover notch to the crank line and checked the valves.. then I rotated another 360deg and checked valves again. I'm on when it's on both valves are closed on cylinder 1.. I don't look to see which valve opens next..
Expert:  Tool Hut replied 1 year ago.

When you are at top dead center and you place the distributor pointing at 1 you should always roll the engine and verify which valve is next to open. It should be exhaust. Both valves will be closed when piston is up both times. So it is possible you are 180 off

Customer: replied 1 year ago.
ok, what's the fastest way to do this without having to remove the valve cover
Expert:  Tool Hut replied 1 year ago.

it is either remove valve cover or pull distributor and turn it 180

Customer: replied 1 year ago.
how much time do I have between responses. both of those things take time
Expert:  Tool Hut replied 1 year ago.

3 days until it times out. you can reply after that

Expert:  Tool Hut replied 1 year ago.

I am pretty confident that you will find this fixes it. as long as wires are hooked properly.

Customer: replied 1 year ago.
ok.. what time you working till
Expert:  Tool Hut replied 1 year ago.

I will check in morning. I will be answering questions for another hour or 2

Customer: replied 1 year ago.
did the 180 deg turn on rotor.. no go
Expert:  Tool Hut replied 1 year ago.

shoot I was pretty confident that was the problem. Have you tried spraying carb clean and see if it runs?

Expert:  Tool Hut replied 1 year ago.

Did the distributor come out of truck then> Have you tried swapping with one that came out of engine?

Expert:  Tool Hut replied 1 year ago.

Are you confident that it is pointed to the right plug? Also are you sure wires are all hooked up?

Customer: replied 1 year ago.
I sprayed carb cleaner, fuel, I've tried 3 other distributors. replaced the icm 3x, I'm at a point where I'm convinced my spark can't jump a 1/4 " gap.. that's just my guess though.. cuz I have spark from coil to plug with small gap, but no spark from coil to dizzy to wire, that's a huge gap by the way, to plug..
Expert:  Tool Hut replied 1 year ago.

Is this what your distributor look like?

Customer: replied 1 year ago.
Expert:  Tool Hut replied 1 year ago.

Why the big gap. do you have correct rotor?

Customer: replied 1 year ago.
it's the same distance among the other 3 rotors I have..
Expert:  Tool Hut replied 1 year ago.

no way that should be a 1/4 inch

Customer: replied 1 year ago.
it's a wide gap, I've seen videos of people drilling holes in cap to see spark and it jumps sometimes 3/4 inch..
Expert:  Tool Hut replied 1 year ago.

If you attach a test light to ground and crank the engine with the wire off coil and hold the test light to coil how far will spark jump? Make sure you have good ground

Customer: replied 1 year ago.
it barely jumps an 1/8 inch.. weak little orange spark, should be bright white
Expert:  Tool Hut replied 1 year ago.

Is the coil mounted? DO you have another coil?

Customer: replied 1 year ago.
I've swapped coil 3 times, they all the same
Expert:  Tool Hut replied 1 year ago.

what is the voltage at the pink wire? again are you confident that all of the wires are hooked up properly? Specifically at the starter?

Customer: replied 1 year ago.
there are only 2 wires at starter.. kinda hard to mess that up.. the harness came out of a 4x4 and my truck is 2wd if that makes a difference
Expert:  Tool Hut replied 1 year ago.

What is the voltage of the pink wire? The ground is at least as important also.

Which computer did you use?

Customer: replied 1 year ago.
pink was 12.25... tried both computers
Expert:  Tool Hut replied 1 year ago.

OK. So lets get back to basics

What engine did truck have in it? same or V6?

Which computer is in truck now? If engine size is the same make sure you use computer that belongs to truck

I am attaching a theft learn procedure I suspect you have it in theft mode

Customer: replied 1 year ago.
both trucks have the 5.7, I'm using the computer that was originally with truck,.. I tried the theft mode procedure and a security light does not turn on,..I'm stumped..
Expert:  Tool Hut replied 1 year ago.

I do not have a lot of time tonight. I would suggest doing a fuel pressure check. check fuel volume as well.

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