vehicle Speed Sensor

[sickblazer]

I have a 90 k5 blazer and it cranks over but no fuel is coming out of the injectors I am getting fuel to ghe tbi .but when I checked the obd1 the only code I was getting was the vss code would the vss being bad cause the computer to stop the injectors from working

 

[dhcomp]

Most of the time, when you have spark and no fuel at injectors, its the ignition module in the distributor.

VSS code would not be related.

My 91 is the same distributor/injector setup, and this has happened to me more than once.

Buy ONLY the stock AC Delco brand ign module, or you'll be replacing again in short order.

Easy to swap, just pull the wires and distributor cap, unscrew, and reinstall.

Best of luck.

 

[sickblazer]

Also my crank fuse keeps blowing as soon ss I try to start it

 

[dhcomp]

Also my crank fuse keeps blowing as soon ss I try to start it

I would suggest you take a look at the wiring down by the starter. The purple "crank" wire, as well as the main feed to the fuse block, drop down from the passenger side of the firewall into a little metal pipe down by the starter and bellhousing.

I had a lot of exposed wires down there that needed to be properly sealed. Also, check the fuseable links down there.

My guess is your purple wire is shorted.

How do you know you aren't getting fuel if you can't crank the motor?

The fuel injectors should only fire during cranking and running, and not fire when you just have the key on.

 

[sickblazer]

I can crank the motor and also it has an electric fuel pump.i put a noid tester on the injector wires and it is pulsing but still nothing coming out of the injectors when I crank it over and also there is no wires running into a tube on the passenger side of the firewall

 

[dhcomp]

I can crank the motor and also it has an electric fuel pump.i put a noid tester on the injector wires and it is pulsing but still nothing coming out of the injectors when I crank it over and also there is no wires running into a tube on the passenger side of the firewall

I'd still bet ignition module.

If you trace the wires from the starter, you'll find the tube i'm referencing. Its just a wire guide, probably 6-8" long, attached to the belhousing down by the starter.

I have definitely found some exposed wires down there.

 

[sickblazer]

I got the fuse to stop blowing and now I am getting obd1 code 42 I can start my blazer and if I keep it at 1500 rpms or higher it will run but as soon as I let off the gas the injectors stop working and it dies could this be the ignition control module

 

[diesel4me]

Did you check the fuel pressure?...sounds like the pump is dying or has low output...might be low voltage going to the pump,lots of GM's have corrosion problems on the fuel pump wiring plugs and the wire itself coming from the front of the vehicle gets gangrene and causes hard to diagnose problems like these...

 

[dhcomp]

If its dying at low throttle, its probably not ign related.

Search that code online, lots of good info.

Id lean towards fuel pump / fuel pressure, or a bad IAC causing stalling at idle.

 

[dyeager535]

Go borrow autozones fuel pressure tester. Use it before and after the fuel filter to rule the filter out as a problem. If pressure is below about 10PSI (GM spec is 9-13PSI, but anything less than about 10 will cause some issues.

Seems odd that it runs better with throttle though, a weak pump (or split tank hose) often idle ok, but die as soon as you try and use the throttle. But the fact you aren't getting fuel at that point seems to indicate that you do have a fuel delivery issue.

 

[paratrooper307]

Could be your timing is off. I had an issue where my hold down loosened and the distributor rotated. Couldn't hold an idle on account of the timing being retarded, but give it more gas and it would hold a high idle fine as the advance kicked in.

A vacuum leak could also cause problems idling.

Don't know if you've checked these already, probably a slim chance, but I've learned before that it's always possible to mess up something else while rooting around under the hood, and the couple minutes checking the basics can save some aggravation.