Hey guys. Okay so quickly here it goes. Runs great and passes smog in summer. Cold months roll in and or rains and it won't start. Everything for fuel issues from the pump/filter/injectors and tps have been replaced due to previous psi dropping with the pump. Dist/cap/rotor/plugs/wires also replaced with dealer av Delco parts. O2 sensors all replaced when Whaley rusted out back in Pa. Blazer has run amazing since all this work was done. Been done for a couple years now. Starting this year IF I get started it running really bad. Almost like not on all cylinders. Throws a p0420 code. After it warms up and stops sputtering the CEL goes off. Starts right up on my lunch break but if I let it set for more than 2 days it will just turn over and turn over. I spray ether down it's throat and still nothing. I know it's getting gas and I know it's getting air and spark. My only thought is maybe some sort of choke issue? Maybe the computer doesn't know its cold? My temp gauge does not work. Went out a little while ago. I don't know. It's weird and freaking annoying. I drive this thing max 4500 miles a year but I drive it everyday

 

Just did the fuel pump on mine. The issue I had was it wouldn't start when the outside ambient air temperature was below freezing. Since replacing the pump I have not had a single issue despite the temperature falling into the low teens several times. I think that took care of it for now.

 

My fuel pump is 3 yrs old. I would think and hope it is not fuel pump.

 

Also if I sprayed ether wouldn't it have at least started for a little? My 88 blazer did and so has my TA

 

Not a good idea to use ether. One stray spark or a backfire and you've got an instant flash fire! Use carb cleaner in a spray can, much safer.


If it doesn't start when adding "fuel", the problem is not fuel related. Time to look for an ignition problem. Needs to be a blue, not orange, spark at each plug, and it needs to jump a half inch gap.

 

Thanks hook. Yeah I know ether isn't good but it was one of those moments where I was so fed up I didn't care if it burnt to the ground.

Little update. Temp gauge works now. Loose connection on driver side.
Anyway. When I get off work today I'm going to check out the cap and rotor and see if anything looks fishy. What's the best way to test for spark?

 

Looking at the distributor cap, is kinda like looking at bath water... ya can't tell if it's good or bad until you test it If it's been a while, or it's not an AC Delco cap & rotor, replace it.


First thing to check is pull the coil wire off of the distributor cap. Stick a small screwdriver in the wire you pulled off the cap. Prop it up so the screwdriver shaft is about one half inch from ground. Crank the engine over and watch for a blue, rhythmic, spark to ground as the engine is cranking. Also watch for any stray sparks to ground from the coil housing. Post your results.

 

Well. I am pretty sure I found the issue. I had some daylight left after work so I pulled the dust cap and rotor off. They were heavily corroded. Green flaky corrosion. The kind we find on the electrical parts at work. So I'm thinking condensation is getting inside the cap somewhere. I check the wires and everything seems fine. I go to put the cap back on the both screws are stripped out. So this whole freaking time the cap is loose and just probably vibrating around. I'm sure with it being so loose that how moisture is getting in there. Also is there a fix for this? I know I'm not the only one with this issue because I have read about it on here before. I will call in the morning to see if it is covered under my warrantee from 3 yrs ago. I would post pics but it seems I cant

 

The "corrosion-like" substance on the cap terminals is normal. The terminals are aluminum, which is a much better conductor of electricity than brass. The problem with aluminum is that it corrodes. When the cap is replaced, silicone dielectric grease is applied to each terminal. The grease helps stop the corrosion process, but it crystalizes when the spark goes through it, leaving behind the appearance of corrosion.


Now for the stripped screws. Unfortunately that's pretty normal too, especially when someone gets carried away tightening the screws, or they reuse the old screws. The new cap and rotor come with new screws that have thread sealer on them. Snug them just enough so the cap doesn't move, that's all they need. The correct "fix" is a new distributor. The "answer" is this one: White Performance Detail Description All aluminum housing, not cheesy plastic like the OEM and most aftermarket replacements. It comes with a cap and rotor, toss it in the trash and install an AC Delco cap & rotor

 

Wow. I can't belive how inexpensive that is. Damn I really would hope this is it. I am sick of dealing with this thing. I have had this blazer for 11 yrs and the moment I let one shop test and replace the full pump and cat I had had nothing for issues.