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24 Posts
Sorry for the long post
I’ve been trying to diagnose my stall/ no start problem for a while now. I need some expertise.
Vehicle: 1989 s10 (2.5 tbi) 2wd w/ 5speed
80% of the time it won’t start on the first 5 attempts or not at all.
19% of the time it will start and die a few times then run if I give it throttle to keep it going. And the 1% it will start right up and run perfect. Regardless, while diving it will stall out. Speed, temp, throttle position, fuel level, you name it, has no effect on when it stalls. When it stalls it will not start again. There was about a week when I could wait 10 or 15 min and it would start and run again to get me home. Now I can’t even get that to happen. I can get it to run for just a couple seconds with starting fluid. ( note that the injectors are still spraying fuel when it whiny start). Only other symptom is a hesitation with throttle. It will bog before acceleration. This is worst when cold.
You would think fuel problems right? Well, I have done everything fuel side. Drained tank and new fuel, checked grounds for pump, checked 12 volts to pump, checked fuel pump relay and replaced, replaced fuel pump, replaced fuel filter, checked fuel pressure at throttle body, I even replaced the injector. Everything is either replaced or passes with flying colors. ( note these tests where done in both start and no start situations).
so my mind turned to the computer, something must be telling the computer to send more or less fuel causing this. Because after all the injectors are spraying fuel, must not be enough? So I start checking all the 5v reference sensors. Everything has good continuity with ground through the computer and are getting the appropriate signal strength. I even replaced almost all of them. Map, tps, idle air, temp sensor and I think one other I can’t remember. (Again tests done in both start and nostart situations) all checked out. I even replaced the computer and one point.
so if it’s not fuel then maybe it’s electrical? Like maybe it’s getting enough fuel but spark isn’t strong enough to ignite? (it has spark in both start and no start situations). New plugs, distributor cap, rotor, hall effect switch, ignition control module, spark plugs I think I even replaced the coil but it’s been a while. Still no change.
I can’t find any vacuum leaks with the old soapy water trick, and all the grounds I’ve checked have been great. I’m at a total loss. I’m at the point where I wouldn’t even be mad if it was the dumbest thing ever that I over looked because I just want it fixed.
thank you!
I’ve been trying to diagnose my stall/ no start problem for a while now. I need some expertise.
Vehicle: 1989 s10 (2.5 tbi) 2wd w/ 5speed
80% of the time it won’t start on the first 5 attempts or not at all.
19% of the time it will start and die a few times then run if I give it throttle to keep it going. And the 1% it will start right up and run perfect. Regardless, while diving it will stall out. Speed, temp, throttle position, fuel level, you name it, has no effect on when it stalls. When it stalls it will not start again. There was about a week when I could wait 10 or 15 min and it would start and run again to get me home. Now I can’t even get that to happen. I can get it to run for just a couple seconds with starting fluid. ( note that the injectors are still spraying fuel when it whiny start). Only other symptom is a hesitation with throttle. It will bog before acceleration. This is worst when cold.
You would think fuel problems right? Well, I have done everything fuel side. Drained tank and new fuel, checked grounds for pump, checked 12 volts to pump, checked fuel pump relay and replaced, replaced fuel pump, replaced fuel filter, checked fuel pressure at throttle body, I even replaced the injector. Everything is either replaced or passes with flying colors. ( note these tests where done in both start and no start situations).
so my mind turned to the computer, something must be telling the computer to send more or less fuel causing this. Because after all the injectors are spraying fuel, must not be enough? So I start checking all the 5v reference sensors. Everything has good continuity with ground through the computer and are getting the appropriate signal strength. I even replaced almost all of them. Map, tps, idle air, temp sensor and I think one other I can’t remember. (Again tests done in both start and nostart situations) all checked out. I even replaced the computer and one point.
so if it’s not fuel then maybe it’s electrical? Like maybe it’s getting enough fuel but spark isn’t strong enough to ignite? (it has spark in both start and no start situations). New plugs, distributor cap, rotor, hall effect switch, ignition control module, spark plugs I think I even replaced the coil but it’s been a while. Still no change.
I can’t find any vacuum leaks with the old soapy water trick, and all the grounds I’ve checked have been great. I’m at a total loss. I’m at the point where I wouldn’t even be mad if it was the dumbest thing ever that I over looked because I just want it fixed.
thank you!
