GM 1987 Suburban 350 tbi: no spark (also no throttle body installed)

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Feb 28, 2019
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So I bought a Suburban for 200 bucks.
Sitting since 2012.

STATS

-1500 (6 lug)
-5.7L/350 tbi
-700R4 Automatic Transmission
-ODO Reads 60,000 (Guessing 160,000)

Wouldn't start and my gas peddle was stiff so I pulled the seized up throttle body to try and rebuild it. But ended up with 6 snapped off screw heads, 2 corroded injectors. 1 seized throttle body core, and a parchrige in a f***ing pear tree.
So moving on I noticed that I wasn't getting spark at all. so I changed the coil with a good one I had.. nothing.. So i checked to see if my distributor was spinning and is just fine. Bought a new rotor and dis cap and still nothing. Then I pulled the ignition control module off and put it on one of my other suburban 350 tbis and works great (tho looks like s*** but still) I did notice that the positive and negative plug on the back looks like it was melted to nothing so I cleaned it up with brake cleaner and wrapped it up with some high quality 30 year old used electrical tape from under the dash and I think I got it pretty nicely and plugged in the other ignition control module. I'm assuming that's not the problem and if it's not.
Any ideas?? I was thinking maybe the throttle body being uninstalled?? No throttle positioning.. Maybe a fail safe of sorts.. only other thing I can think of is fuel inertia switch or a ground out issue. I'm not gonna order a 300 dollar tbi unit to drop in a 200 dollar beater w/o a heater but I'll pull out my other tbi to test in this if it's a possibility it might be related to the no spark issue.
 
Last edited:
Joined
Nov 9, 2012
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Location
Olathe, KS, USA
On those years, typically the spark was completely independent of the TPS.

My first thought was ignition module.

Was the truck wrecked? If so, yes it could be an inertia sensor (don't know where) to shut off the fuel pump, but not necessarily the spark.

How about the crank sensor? Usually there is a crank sensor that allows some of the stuff to run, but it's not being used as the trigger because that should be the distributor.

I'm guessing if there are melted wires in one spot, they are melted in others as well. Look at ignition switch, wires under dash, other areas in the harness.

Did you actually pull a plug wire to verify no spark?

Is it plugged into the distributor cap? (HEI right?)
 

jvalex

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Mar 4, 2018
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Here for this tthreeeeeeeeead will be back later, though
 
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