geozeke

My 93 Silverado will start for a few seconds and then die. I am not that familiar with TBI. When the truck is cranking I can see that fuel is being sprayed from the injectors onto the throttle plates. I would describe the spray pattern as similar to what would come from a bottle of window cleaner. Not a real fine mist, but a coarser spray. It that what I should expect?
I have already removed the injectors, installed new injector filters and O-rings and also new pressure regulator parts (has to buy all of that just to get the right set of gaskets...) Everything looked decent to start with anyway.
This year of truck has no valve on the fuel line to test the fuel pressure, so it is a pain to rig up a fuel pressure test. If the spray pattern is as it is supposed to be, then maybe I don't need to bother with that... If not, then fuel line filter would be next, before ripping out the fuel pump.
I also tested the idle air control valve, the throttle position sensor and temperature sensor, per the Haynes book, all are on spec. I also cleaned the idle air valve and passage into the TBI unit. Fuel pump has power to it. Distributor cap and rotor replaced, as they needed it anyway. Spark tester shows that I am getting spark. No OBD I codes on the computer.

2009Sierra

When you turn the key to ON can you hear the fuel pump run? My fuel pump on my old 93 started to go and the truck would start and then die. I turned the key to on and I could here the pump start to run and then it just slowed down and died. Needless to say I had to replace the fuel pump. Not exactly a fun job.

A clogged fuel filter will generally show poor performance - bad acceleration. But, if it's over due to be changed then probably won't hurt to change it. Easy and cheap job. I'd try that before replacing the fuel pump.

Speedy650

change the filter and run some injector cleaner through it.

lukemoore646

my 93 did the same thing, it was the IAC, not saying yours is the same problem but the way i found out is by cracking the throttle while trying to start it, then presto it would run, TBI is great till little problems like this occur

MDTAHOE

Will it run if you hold the throttle some? Can your drive it using two feet, to keep it running a stops? If so how does it run for normal driving? heavy acceleration?

geozeke

I worked my way through the troubleshooting to the IAC also. After I cleaned it, the truck will finally hold an idle for about 10 or 15 seconds and then sometimes die, or start to die, recover for a few more seconds and then die. Opening the throttle will cause it to idle longer. So, the problem would seem to be IAC related.

geozeke

Well, I have replaced the Idle Air Control and I still have the same problem. I measure about 10 volts on each pair of wires coming into the IAC connector, does anyone know if that is correct?