Getting fuel and spark - no start.

[AlaskanDad]

I have another thread floating around, but now that I have some new information, I thought it was time for a thread centered around some better information.

My truck is getting fuel and spark, but isn't starting.

1987 with 350TBI. Just got a new fuel pump / filter and was timed.

Anyway ideas would be helpful.

 

[ryoken]

when you say won't start, what's it doing? crank and do absolutely nothing? or does it try to light a bit here and there?

fuel, fire and air..

I'm gonna guess you have a coil sh*tting the bed... it's probably weak spark.. is it just a yellow spark, or is it a snapping blue spark? make sure you pull some plugs and they are ok and not flooded..

 

[AlaskanDad]

I grounded the plug on the alternator bracket and it was yellow. At first there was nothing but when tapping I could see and here it.

Also, it does nothing but crank; does not sputter at all.

 

[ryoken]

try a new coil..

 

[-stew-]

A new coil and new plugs. If you've been cranking the daylights out of it those plugs are fuel soaked and they are shot.

 

[AlaskanDad]

Turns out the coil was original much like rest of everything else. This is a crate engine with only 61k miles. Who ever commissioned the replacement decided not to replace any sensors, etc.

It tried to start, but with the cold weather and my many attempts over the last 4-5 days my batteries were drained. When my wife gets home this after I will jump the truck.

Hopefully this was he problem.

 

[ryoken]

so you put a new coil in and it tried to light off?

 

[AlaskanDad]

Got my buddy to try and jump me and nothing happened. It tried to light off, but no actual power. All the other attempts failed with it doing what it was before. Just turning.

 

[ryoken]

It tried to light off, but no actual power. .

what do you mean by this... was it turning over and some cylinders/plugs where firing but it wouldn't start?

is this with a new coil? have you pulled and checked some plugs?

 

[AlaskanDad]

Yes. It wanted to fire up, but before it could actually stay ignited it let go. Do not know any other way to describe this.

This was with the new coil and have not tested the spark since. I have been trying to juggle for a math test tomorrow morning and this.

 

[ryoken]

I would pull the plugs as mentioned and make sure they are not fuel soaked/fouled... if questionable replace em..

you may also want to pull any codes if you get a chance.. all you need is a paper clip.. here's how...


http://www.troublecodes.net/gm/

 

[AlaskanDad]

Was unable to pull codes when I tried yesterday. The plugs are only 8-weeks old. However, they are black like coal.

Did not think that would make a difference since the old ones were nearly as dark.

Maybe I will run into town real fast and replace them all.

 

[ryoken]

black, rich fouled plugs fire like cr@p... replace them...

that also indicates it had an issue when running...get it fired back up with fresh plugs.. than check the plugs after a few days of running and see what they look like.. it was more than likely the coil failing, weak spark not burning the mix well..

 

[shady]

i should have seen this thread 20 minutes ago I just looked up OBD codes and checked my truck.... came up with a weird one and I started a thread about codes

somehow It doesn't seem like our trucks our that far off of each other at the moment different issues sorta, but not by a lot

 

[AlaskanDad]

Finally got time to install new plugs and it fired right up. I have yet to take it out for a drive, but plan on it as soon as the kids are in bed.

However, after it warmed up a bit I gave it some throttle and it nearly wanted to stall the revolutions came back towards idle.

 

[ryoken]

is the service engine light on?

 

[AlaskanDad]

Took it out for a 30 minute drive; it did great.

Lots of power.

Thanks for all the help. Funny how this all started because the air cleaner lid slipped, fell, and cracked the vacuum line from the lower font TBI into the EVAP. This in-turn caused it to pour fuel into the engine which made the plugs foul and put further strain on the original Coil pack.

Running like a champ.