!997 Blazer will crank but not start. Have 60 psi fuel pressure to rail. Have spark on both sides of motor at plugs. Have compression. Timing seems to be close if not dead on. Have all dash lights when turn the key to on and after I try start it. Has not even attempted to start. Even when spraying starting fluid or dumping gas directly into intake. New fuel pump and filter 6 months ago. New MFI spider 1 month ago. Only code is if we have throttle position sensor unhooked, get a low volt throttle position code. No other codes. Even if they are unhooked. New cap, rotor, wires, and plugs. New coil. Tried another computer. Tried another ignition control module. New map sensor.
Sounds like youve really done your home work all that comes to mind now is try a cam posistion sensor this would keep your car from starting as well if that is good you can aslo try a crank sensor. you will get all of the readings that you are getting and these sensors can still be bad.
yes the sensors can and will cause all of those symptoms you can put a ohm meter or volt meter on the sensors. should be around 12 or higher volts 0 ohms if you do get ohms it should be very low no more than 4. have you checked your maf sensor (mass air flow) this can be found on the airfilter canister closest to the accordian hose. also the throttle posistion sensor can be bad the computer reads that the throttle should be closed therefore not allowing the car to start. just to rule out any of the sensors id just replace them all they are relatively cheap considering. you may also try to see if there is a vacuum leak or a bad hose(vacuum) the hose may look good on the outside but can be collapsing in on itself inside feel all of the hoses if they are very easy to squeeze together or are very stiff replace them. i hope this will help you.
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I agree with brian 22 but i would replace the plugs even if they look ok i have seen plugs that got washed with fuel and look very good the only other thing i would do is when you have the plugs out squrrt some oil in the spark plug hole then replace the plugs also i have found when replacing the back plug on the drivers side it is very hard i have found that removeing the bolt from the steering shaft at the steering box/gear and pushing the shaft up and off the spline will give you lots of room just do not turn the shaft as you will mess up the clock spring if you do not know what a clock spring is it it at the top of the steering colume under the steering wheel and it is the wiring for the horn air bag and possably other things
Wow a lot of work has gone into this one I see. Ok well with a bad cam sensor this truck will still start and with a bad crank sensor you will lose spark and injector pulse. So return to the basics, you need three things to start this bad boy, one spark, two fuel, and three compretion. To start lets be shur that as you crank the engine the security light is not flashing at you, as far as compretion goes usually it dosent just fail, what i mean is a mechanical failure should be obvious, spark is also easy to test and sounds like you have, feul however is not always about preshure, because you need some volume too, but you said poring fuel into intake had no effect. I have fixed a few of these with a new set of plugs, pull one out and see how much wear they have, it sounds like you are in the right diretion just pay close attetion to details.
you said that it seams to flood right off the bat, i would pull the fuel pump relay and crank engine to clean it out. if it is flooded it should fire and want to start as it cleans the extra fuel out. if thats the case i would suggest a coolant temp sensor. if its not flooded than you need to check compression, on at least 4 cyclinders, min 100psi, most GM cars and trucks have a anti-theft system, called pass-key or pass-lock. any-way look at it this way even if your timming is off and compression is low, eventually if spark and fuel mix you will get a bang, even if out the intake, so the problem is you dont have a good fuel mixture that is fired at the right time. replace the spark plugs, and no sensors yet, if you suspect a sensor just unplug it.
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I forgot to mention that all injectors seem to be firing and 1 of them for sure is firing and giving fuel. We pulled intake plenum off and checked. So my question is would either the crankshaft sensor or the camshaft sensor or both cause all of these symptoms? Is there a way to check/test either of these? Thanks for the help.
new plugs about a month ago. what "security" do you mean? the "MIL" light? It really doesn't flash as I crank it. I would describe it more as a pulsing light.
update: Have install brand new distributor. Have spark at all plugs (removed all and grounded them and they ALL spark). Vehicle is in time. Checked and re-checked that. Still no-start. When the vehicle is cranked and then plugs are removed they are wet with fuel. What could cause this? Almost as if cylinders are being flooded at first crank or, as funny as this sounds, the spark plugs are firing in the head. Head IS grounded.
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