Truck shut off at stopsign on occasion should open my damper permenatly ?

[Hugomartin]

Have you checked your distributor? That little vent in the bottom of it likes to plug up with dirt and corrodes the inside. That made my truck randomly die at lights.

Also jiggle your keys back and forth and see what happens. The coil is hot of the ignition and if the switch is worn out it can cause random shut offs.

Also check the operation of your egr.

I'm assuming you have 87 and up tbi?

My egr is fairly new
I have a brand new ignition switch

Yes I have 87 Tbi 350

Yes the keys jiggling I’ve tried that but it’s pretty tight , I initially thought bad key tumbler n rack

Not sure about the vent on the distributor . My distributor is also new 1 year or so

 

[gmbellew]

if it starts when you put the pedal on the floor, that is clear flood mode. maybe a bad fuel leak into the tbi is flooding it out? or does it die quick like electronics are killing it?

 

[SirRobyn0]

@Hugomartin that "damper" thing is called a thermac. There should be one vacuum line to it that supplies it with manifold vacuum. There is a little thermal thing in there is designed to keep the air flowing into the carburetor close to 90F. You really need to have the hose from the air cleaner to the grill and the smaller one to the exhaust for it to work correctly. Since it looks like your missing both it really doesn't matter what that thing does because it drawing air from the engine compartment either way. You really should replace the missing pieces, but regardless it's not causing your stalling. Wedging it open with a piece of wood will not do anything for you.

 

[Bennyt]

When it "dies" ...is it trying to run but dies or does it just shut off like a switch?

Does it idle fine and only dies after a hard stop?

Does it restart immediately? Any other drivability issues?

 

[Hugomartin]

if it starts when you put the pedal on the floor, that is clear flood mode. maybe a bad fuel leak into the tbi is flooding it out? or does it die quick like electronics are killing it?

It dies fast no stumble , i think as soon as the light turned green it cuts off in drive , seems electrical. Why would it crank slow when i try to start it back up right away?

 

[Hugomartin]

When it "dies" ...is it trying to run but dies or does it just shut off like a switch?

Does it idle fine and only dies after a hard stop?

Does it restart immediately? Any other drivability issues?

it starts after a few slow cranks almost like a dead battery, almost like the dash lights pulse as its turning over slowly. After a few failed attempts cranking i keep pumping that gas pedal while cranking then it finally starts

 

[Hugomartin]

if it starts when you put the pedal on the floor, that is clear flood mode. maybe a bad fuel leak into the tbi is flooding it out? or does it die quick like electronics are killing it?

why would it over spray into the tbi? Would ecm be the culprit maybe running to rich?

 

[Hugomartin]

Any other time i start the vehicle i dont have to flood it with gas, it idles and drives fine

 

[Bennyt]

My experience with those ecm's are they are very reliable and either work or don't work so I don't think that's the issue.

How do you know you are flooding it when starting? You can visually see and smell fuel?

Is gas tank full or low when this happens?

Some of what you are describing sounds like a bad fuel pump or missing pickup. (You stop fast and it uncovers, fuel sloshes while you crank and fires when it recovers)

I believe you have a fuel pressure issue. That could be anything from bad pump, pickup, low fuel level, dirty filter, etc.

I'd change the filter, fill it at least 3/4s full, and drive and check fuel pressure immediately after it dies.

 

[Originalthor]

good call on the fuel stuff. ^^

Also the line being busted in the tank but usually if that brakes it don't want to restart.

I wouldn't rule out your distributor. I went through 3 in one year until they finally gave me back my money and I ordered a good one. Same symptoms pull up to light and went to go and it would randomly shut off.

One other thing I've ran into is if you put in a new coil like a msd one the connector doesn't click in there nice and can make a bad connection.

 

[Hugomartin]

My experience with those ecm's are they are very reliable and either work or don't work so I don't think that's the issue.

How do you know you are flooding it when starting? You can visually see and smell fuel?

Is gas tank full or low when this happens?

Some of what you are describing sounds like a bad fuel pump or missing pickup. (You stop fast and it uncovers, fuel sloshes while you crank and fires when it recovers)

I believe you have a fuel pressure issue. That could be anything from bad pump, pickup, low fuel level, dirty filter, etc.

I'd change the filter, fill it at least 3/4s full, and drive and check fuel pressure immediately after it dies.

I put in a new fuel pump last year I’m thinking I need to add more grounds , the last owner or mechanic seemed to have removed a block ground and spliced the wire to battery negative post instead you can see the electrical tape. May I need to add a tee to ground to the block and “ground” to the neg battery post

 

[BadBowtie]

Do the 1987 EFI trucks still have a vacuum advance on the distributor? I can't remember.

Also, what is your timing set to??

 

[Ricko1966]

Replace everything,or pay someone to properly diagnose it.