Starting problems / gas fumes (1993 TBI)

[SlushFund]

I believe I have an issue related to pressure buildup from gas fumes..
The sequence of events:

Last week I stopped to get gas, and the tank would only take about a gallon before shutting off the pump.
I did a little research, and reasoned it was related to the evap canister. When I got home, I took the evap canister off, and tried to blow air through it (with my mouth..). Some dust came out.

I then went and filled up at the gas station, and the truck would not crank.
I tried a few things, including disconnecting the canister line again, and blew air back into the hole.
I don't know if that helped or not. I may have also pressed the gas peddle down at some point.
(I' later read that pressing the gas peddle down can alleviate a possible flooded condition, I don't know if that was the case).

Eventually, I got the truck to start and have been driving it around on that same tank of gas (with the evap canister hooked up).

Today while driving home, I stopped to grab some chicken wings for the grill, came out and the truck would not start. I disconnected the canister, pressed the gas peddle down, even removed the gas cap, but the truck would not start.
It finally started after about 5 minutes.

My questions:
Does my truck have a purge cylinder, or is that built into the evap canister?
Is there anything on/in/or near the gas tank that could be causing this problem (apart from the evap canister)?
Should I (temporarily) disconnect the canister and get a vented gas cap?
I'll eventually buy a new canister.

 

[df2x4]

Really sounds like unrelated issues to me. I don't see how the EVAP system could prevent the truck from starting under any circumstances.

In relation to the gas filling problem, if it happens again just pull the nozzle out of the filler about half an inch and try again. Should fill right up. My red truck is picky about that on certain pumps.

 

[SlushFund]

It was not related to the pump, I tried pulling the nozzle out and gently squeezing the handle. I tried two pumps. Even went to another gas station. Believe me, I know how to use a gas pump. The pump would shut off and gas would come out of the filler as it were full. It clearly was not full because I had driven about 100 miles before gassing. The fumes in the gas tank need to dissipate, if not it can cause starting issues.

My questions is:
Does my truck have a purge cylinder (for fumes) on or near the tank? Or does the evap canister handle this?

 

[df2x4]

Yeah that's definitely an issue, then. I still don't see how it would cause a no-start, though.

There is a separate purge solenoid, although I'm not exactly sure where it's located. What year truck? The EVAP systems were little bit different between TBI and Vortec motors.

 

[SlushFund]

It's a 1993 TBI.

 

[df2x4]

Looks like you're looking for GM part number 1997201. Here's a diagram I found on GM Parts Direct.

https://www.gmpartsdirect.com/auto-.../emission-system-cat/emission-components-scat

Sorry I can't help you with where it's at, both of my trucks are Vortecs.

 

[SlushFund]

Thanks! Just need to locate the sucker now

 

[89RCLB]

Hopefully this helps...

You must be registered for see images attach

 

[77Impala]

On the fail to start issue that happens from time to time, check that you have spark when the truck does not start. I do not think that the EVAP canister or if yours has the tank pressure control valve would cause the no start condition.

I would recommend if the truck does not have spark to have the Ignition Control Module (in the distributor under the rotor bug) checked. The module does have a start feature built into them and that portion could be bad.

 

[SlushFund]

OK, maybe it was just a coincidence that it happened on the same day the first time. I did need to replace the ignition control module a few months back. Maybe something is stressing it?

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