islanti

Hi guys. so i'm trying to diagnose an issue

Yesterday morning when i fired up my truck it started fine but idled very rough (engine was shaking very roughly which caused most of the truck to shake) but it went away after about 20 seconds of idling. it has done this a few times in the past month or so, but it always goes away after a few seconds.

This morning when i went to start up, it cranks but doesn't start. you can actually kind of hear when it would normally fire up (after a couple cranks), but it just continues to crank after that. also, the check engine light has come on for the first time

With the key in the ON position, i jumped TE1 and E1, and the check engine light just flashes repetitively. also, while in the ON position, i can not hear the fuel pump. however, when i jump FP and B+, you can immediately hear the fuel pump kick in. but when i try to start it again, it still fails just as before

It's nice to know my fuel pump is (possibly) working fine, but if it's simply an electrical issue, then why isn't it starting when i bypass the connections?

I'm going to have another look tomorrow. any ideas what to check next? i'm not sure if this is related at all, but might be worth noting that it has been raining yesterday and today and the temperatures are beginning to drop

Any help is greatly appreciated. thanks

jb451

Fuel. Air. Spark. You know the engine is getting air, pull one of the plugs out along with the wire and have someone crank it. If you see an arc on the electrode, you know you have spark and now have a fuel issue. Also check all vacuum lines to and from the engine. I highly doubt its a vacuum line but check just to be sure.

islanti

So i had another look today. i loosened the bolt at the cold start injector and gas was present. i also removed a spark plug and could smell fuel on it. this, as well as being able to jump the fuel pump leads me to think the fuel system is (possibly) fine. unfortunately nobody was available to help check for spark. next i swapped the mass air flow sensor with another one i have but it made no difference...

I tried cranking it again with the gas pedal down, and it barely starts and shakes A LOT and just wants to stall. without the gas pedal down, it basically just stalls right when it would normally start. this makes me think the issue is related to the rough idle and shaking i've been having occasionally for the past few months as described in my first post.

Kiroshu

Sounds like ignition system failure.

Defiantly need to verify "spark."

Possible failed ignition coil and or igniter assembly.

Possible faulty/damaged distributor components.

islanti

I will try checking the sparks tomorrow. also might be worth mentioning that when it used to shake on startup, i would always hear a "swishing" sound (like fluid rushing through a small tube) after the shaking went away. as if it was trying to work something through the system? that's the best i can describe it

islanti

Just checked the ICV. clean as a whistle