93 k Blazer

[Australia]

I have a 1993 K Blazer It will start but wont keep running I get good fuel ,sprays evenily from the ejecters Ive changed the coil ,spark plugs ,pick up in the distributor tps ,idle air valve new catalytic converter

[Chris Stewart]

Is the "Check Engine" or "Service Engine Soon" light on?

[Australia]

no the truck was running fine then it cut out driving down the highway.It may have had a code but ihave disconnected the battery since so really have no idea also the control module has been changed

[Chris Stewart]

When starting, does the engine quit as soon as you release the key?

[Australia]

no it runs for about 10 15 secs coughs and farts and then stalls if i keep pumping the gas it will run but i have to rev the shit out of it ive checked the timing its good. while running it misses bad.

[Chris Stewart]

Sounds like it's losing fuel pressure. There's a fuel pressure check device called a Schrader Valve near the throttle body with a black cap on it. Borrow or buy a fuel pressure test kit, your local auto parts store should have one...here's mine.


I'm not sure but I think TBI injection needs 9 to 12 psi, all help gratefully accepted. Watch what the fuel pressure does when you start the motor.

Even if the fuel pressure is in spec, there's a screen inside the TBI somewhere that can be cleaned too.

[Australia]

It doesnt have a fuel bar where you can connect a pressure gauge. it seems to have a good fuel supply it actually back fires through the throttle body and flames shoot up i think because the fuel isnt getting used up do think it could be the control module in the distributor i did replace it a couple of years ago. when it happened before it would completly cut out and not start at all but then it would be ok for a couple of days then it would cut out again while driving along but i could always get it going again.

[Chris Stewart]

The module in the distributor acts as a crankshaft position sensor too and with that info, the computer tells the coil when to spark.
I've seen the "star wheel", mounted on the distributor shaft on a 305 V8, crack then wobble, sending crazy signals to the computer. See if yours is loose. A rust ring may be visable.

[Australia]

Ive had the distributor apart when i changed the pick up coil the star wheel is good and tight and no cracks

[Australia]

Still cant get the bloody blazer runnin can any one give me an idea of what to do besides flat bedding to a dealer.

[Chris Stewart]

Find the Assembly Line Diagnostic Link (ALDL) at the lower portion of the dash...it's the device for checking Trouble Codes. Maybe the computer "remembers" something to lead us to your problem. Jumper the 2 top right holes with a piece of wire or even a paper clip then turn the keyswitch on. The Check Engine light should flash once then 2 times...1-2 or what's refered to as a condition code 12 which is the computer's way of letting you know it's now in diagnostic mode and is preparing to flash more lights in 2 digit sequences. It'll flash each one including the aforementioned code 12 three times. After it gets through, it'll flash the code 12 again letting you know it's played all the stored codes.

[Australia]

I did the codes got code 34 and 42 i changed the map sensor as indicated by the manual and 42 is EST elctronic spark timing i think the 42 happened when i changed the pick up coil because i didnt disconnect the battery so just to be safe i changed the control module in the distributor i cleared the codes. now i have no codes but the truck still dosent run its better but it wont stay running im thinking may be you were right about the fuel pump but how can i check the pressure there is no room to attach a gauge because there is no fuel bar with the shrader valve and no room to put any fittings or adapters for a gauge .

[Chris Stewart]

The fuel filter and where the fuel line goes to the Throttle Body has fittings. Make up fittings to one of those connections and an 1/8" NPT for a 0-30 oil pressure gauge.
You're working with gasoline, bad fire hazard...be careful, no smoking and no fuel leaks allowed.

[Australia]

Got the 93 Blazer running.Turns out to be the bloody fuel pump. Thanks for all your input mate.