Amazing Blazer

97 Chev Blazer 4.3 CPI No Start

Obvious why this was a no start, but what it led to will amaze you. After hooking it back up, (the connector at the Ignition module) it started, but ran awful for about two minutes , then died and wouldn't restart. Back to square one, I still have a no start, so I refresh my mind and started over. It cranked fine, battery volts was good, fuel gauge reported a full tank, fuel pump prime exsisted and sounded ok, ignition was good. Fuel pressure reported 10 PSI, I pulled the fuel tank cap and listened to the pump through the filler neck and it sounded like the tank was empty, (sometimes tanks are insulated and I can't hear the pump that well) sure enough, it was. After adding five gallons or so, pressure jumped up to 65 psi where it belonged, now I start it up and it runs awful, missing badly, MIL light flashing.

Going into onboard tests reveals cylinders four and five doing zip, a whole new ball game, and a lying tank sender

Part of the reason I did this article was to show you this test adapter I built for the vortec engine, it hooks to the injector pins in the top of the plenum and allows easy testing of the injectors. Now its much easier to check resistance, or flow test them, plans will be available soon. (onboard tests are included in some PCM's, but not all)

I also modified my injector pulser to hook up to this adapter as well as other injector types, this allows testing of more than one type injector. After flow testing injectors, number four and five were totally plugged, they did not flow anything, resistance tested good on both and you could hear them pulsing.

In concluding, I can't imagine how this all happened, especially how the module connector got loose, it seemed tight upon reconnecting. Oh yeah, it had to have a tank sender as well. You should have seen the bill.