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TBI newb-no start **SOLVED**

mrk5

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Okay I'm an old carburetor die hard that's entering the 21st century. I picked up an '88 K5 and I'm planning to swap the TBI onto my '84.

The '88 hasn't been started since 6-8 months ago. I want to make sure it runs good before I swap everything onto the '84.

So onto the meat of the problem, it won't start.

My guess is fuel pump. The truck cranks fine and if we pour little fuel in the throttle body, it will run for the 5-10 seconds the poured in fuel supplies.

I don't hear the pump running like I do on the TBI trucks I've been around.

We tried jumping a wire from the positive on the battery to the little plug below the fuel pump relay while cranking the motor. Nothing changed. FWIW, we did get a spark out of the lead when contacting the terminal. I guess I really don't know what that little test lead is supposed to tell me.

Anything else I should test before just replacing the pump? I do have spare pump from my bro-in-law, so at least I don't have to spend money.

One other item of mention, I don't want to leave any possibility out. I don't know how much charge the battery in the truck had. I put it on a trickle charger for 8-hours. Somebody had cut the terminal clamps off the cables so we just vice gripped the bare ends on the battery along with a large gauge wire coming from the alternator. Would low battery voltage be an issue? It seemed to crank just fine.

Sorry for the long post, but I know I hate it when others ask for trouble shooting without enough background.
 
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if it is cranking and you are hearing no fuel pump first check the wires to the fuel pump. If you got a spark from the lead to the fuel pump, this could be becaause the wire is grounded before the pump or the pump has a internal ground(means the pump is bad). Also you might want to check to see if the injectors are getting a signal. Using a test light it should blink while cranking and hooked up to the injectors.
 
Cool, I'll try that with the injectors. Thanks!

I was already planning to trace out the wiring.
 
Hey, welcome to the wonderful world of fuel injection!!:wink1:
Let us know how you get on. It'll be worth it in the long run......I think!
Damn...next thing you know you'll be burning your own chips!:D
 
I just finished putting a 327ci in my 88 k5 and when I tried to start it the injectors wouldnt fire then i realized that I forgot to hook up the wire from the battery to the back of the alternator.You said that your cables were cut off and Im willing to bet that you just need to hook a wire from the positive terminal on the battery to the small stud on the alternator.
 
Yeah, my brother-in-law caught that one. The first time I tried, we didn't connect that wire. We tried it again with that wire connected and still no start without us pouring gas.

Hopefully I'll have time to try it out again tomorrow.
 
Here is the troubleshooting list straight out of the manual.

1. Fuel Tank Empty
2. Battery discharged, engine rotates slowly
3. Battery terminal connections loose or corroded
4. Fuel not reaching fuel injection unit. Check for clogged fuel filter, defective fuel pump, or clogged fuel tank vent lines

5. Faulty distributor components
6. Defective oil pressure or fuel pump switch
7. Low cylinder compression
8. Valve clearnces out of adjustment
9. Water in fuel system
10. Defective ignition coil
11. Dirty or clogged fuel injector
12. Wet or damaged ignition components
13. Worn, faulty, or incorrectly gapped spark plugs
14. Broken, loose, or disconnected wires in the starting circuit
15. Loose distributor
16. Broken, loose or disconnected wires at the ignition coil or faulty coil
17. Timing chain failure or wear affecting valve timing.
 
ivie29 said:
Damn I thought that was it for sure.
I know, I wish it was that simple. :smirk:

James, the funny thing is I think the tank might just be bone dry. I'm going to add some fuel. Wouldn't it be funny if that is what the problem is.:rolleyes:
 
mrk5 said:
I know, I wish it was that simple. :smirk:

James, the funny thing is I think the tank might just be bone dry. I'm going to add some fuel. Wouldn't it be funny if that is what the problem is.:rolleyes:
A friend put his tank back into his '59 caddy. When I got there he was cranking it over with no joy at all.
Fuel? I asked.
Put a gallon in. he said.
Well a gallon in the bottom of a tank that big probebly sits less than an inch deep. Put another gallon in and it fired up straight away!
 
That did it, 2 gallons of gas and it fired right up and ran.

So I'm feeling like both :doah: and :saweet:
 
Hee-hee, firefighter184 just earned a reprieve.

You just made top of the HUA list. :haha: :haha: :haha: From now on you shall be my pet project and John shall help me make sure you never forget. :rotfl:
 
mrk5 said:
That did it, 2 gallons of gas and it fired right up and ran.

So I'm feeling like both :doah: and :saweet:
:doah: :haha: All's well that starts well! lol.:D
 
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