1987 chevy 350 tbi problems
grey87
10-08-2007, 12:18 AM
Hello im new to this forum, but i have an 1987 chevy 350 with throttle body injection. it set up for a while, year and half, but it will not spray out of the injectors. checked the wires goin to the injectors and they are supplying juice but the injectors just arent sprayin anyhting. of course it is getting fuel to them cause it steadily dripped due to the fact that it leaked around the seal that i replaced, but the injectors just arent spraying at all. any help or advice?
Cadillakin'98
10-08-2007, 01:06 AM
Sounds like your injectors are clogged. Did you drain your fuel tank and put fresh gas in before trying to fire it up after sitting that long? Gasoline gels up as it sits over time. Guess it gelled up in your injectors or you sent gel-like fuel through your lines which clogged up the injectors. Probably need to ghange all the injectors now but I'd also clear your lines before doing so. You can disconnect the fuel lines and use compressed air to do this.
grey87
10-09-2007, 01:49 AM
is there any way that i can check the injectors to see if there clogged without having to buy new ones? i really dont want to have to spend that kind of money on that if i dont have to. it just seems like there should be a way, i mean is it possible to tear them down and check them?
Sonny01
10-09-2007, 03:59 AM
TBI means Throttle Body Injection and there are only two fuel injectors that sit on top of the engine. The TBI unit kinda looks like a carb.
envoyxuv
10-10-2007, 12:59 AM
I know you said you have juice to the injectors, but have you found out if they're actually pulsing? If you have a 12-volt test light, you can test this. unplug both injectors. You'll need to have someone crank the engine, or use a remote starter with the key in the run position. Connect the test light to the terminals on one injector connector at a time. While it's cranking, the light should be blinking on and off. If it's not blinking, that means it's not getting the pulse it needs to turn on and off. Just food for thought.
grey87
10-10-2007, 03:49 PM
Ok so there not pulsing as you said, i replaced the ecm and still nothing, i did ground them out for a second and they sprayed like crazy so the injectors are good, what else could cuase them not to pulse
envoyxuv
10-10-2007, 04:36 PM
The ignition module supplies the signal to the ecm for the injectors. This dude is located under the distributor cap and has 2 connectors plugged into it. That seems to be a common failure on these trucks. You might also find that you don't have spark.
2000CAYukon
10-10-2007, 04:40 PM
A bad pickup coil can also cause this since it supplies the AC signal to the ignition module (which converts it do DC).
//2000CAYukon
//2000CAYukon
Sonny01
10-10-2007, 05:42 PM
i did ground them out for a second and they sprayed like crazy
If memory servers me correctly there is a grounding wire for the injectors...you might want to check that. It's part of the wiring harness that plugs in.
If memory servers me correctly there is a grounding wire for the injectors...you might want to check that. It's part of the wiring harness that plugs in.
grey87
10-11-2007, 12:24 PM
the new brain box i put on still didnt make the injectors spray, so your sayin it could be the pickup coil, or the ignition module? im gonna try the pickup coil today cause i bouhgt one yesterday. the injectors arent pulsing, but they do spary when you hot wire them and the truck does fire becase you can dump some gas into the injector bowls and the truck will run.
Ripsta7sign
10-12-2007, 01:45 AM
check the ground thats on the thermostat housing screw.IS your fuel gauge reading correctly?
grey87
10-18-2007, 08:59 AM
iv'e checked the grounds and there good. i cant think of anything else that would be holding them back from spraying?
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