I have a 1989 GMc full-size Jimmy (K5 Blazer). Here is what I know. Blazer runs perfect all day and I get home and park it. I get up the next morning and it turns over but won't start. I take off the air cleaner and try to start it. I see that there is no gas going from the injectors into the engine. Furthermore there is no spark. I called a mobile mechanic and he came and replaced the distributor cap, rotor, coil, ignition module, spark plugs, and spark plug wires. Still no spark and no gas. So I check the computer and I get a map sensor code. I replace the map sensor and the code goies away, but still I have no spark and no gas and the truck turns over. The mechanic just wants to keep throwing parts at it (a new computer, and go from there). Any ideas what could have gone out that could cause both of these systems to fail?

 

hey dude, it may be the computer. it controls everything. if you need one get one from the junk yard. there big bucks. good luck bubba

 

you say you can hear the pump turnon ?? then i wuld startchecking distibutor parts will need a book & meter some of this parts you my be able to have check at your part store (autozone) ingnttion module coil pickup / stator . i had a 1988with no spark endup being the pickup had gone bad http://www.partsamerica.com/ProductL...ickup%2fStator

 

computer more than likely can you hear the pump kicking on at all? another thing all those parts you replaced cancels them out so i would deffinitly have the computer checked i think autozone can test them im not sure but its worth a try

 

Yes, I can hear the fuel pump. I heard that the pickup coil can cause these symptoms when it goes. Any thoughts on this?

 

It could possibly be theelectronic spark control (ESC)Module (niehoff part #DR1303) i'm not too sure if the fuel pump solenoid is powered from there or not, it's been a while since i've worked on a gasser. Also i dont know if those early model fuel injection systems will shut down fuel and spark if there is no signal from the oil pressure sender.I had a mid-90's Buick do that on me.

 

I did a little reading on the TBI systems. You should have an EST module (Niehoff ignition control module part # DR411CS) in your distrubutor which sends a signal to the ECM that will synchronize your injector pulses. My guess is if that module is burned out you wont be getting any fuel. Also the part number i provided is for an '89 Chevrolet Fullsize Blazer with a 5.7 V8.
Hope this helps. I had a friend with a camaro that would regularly eat these because his engine ran way too hot.

 

From what I've read here, you've replaced everything but the computer and the pick-up coil.
The pick-up coil can be the problem because they tend to break the wires but not the insulation and the wires still look intact. Every time you step on the gas the vaccum advance pulls the breaker plate and it's kind of like twisting the pick-up coil wires back and forth. (How many times can you bend a wire back and forth before it breaks?)
Check the wires with an ohmeter. If you have "0" ohms, tug gently on the wires and see if they go open circuit.
To replace the pick-up coil, the distributor needs to be removed and dissassembled.

 

Thanks to everyone who helped it was the pickup coil but now i have a new problem https://blazerforum.com/m_117084/tm.htmhere it is if you care to look.

 

I know you've found the problem (pickup coil) but another inexpensive tool to get is a "Noid light". It goes across the wires to the injector on the TBI and helped me diagnose a bad computer on a '90 Blazer that had similar problems. With mine, I could get it to run with carb cleaner sprayed down the throttle body but had plenty of fuel and pressure. The computer was not activating the injectors and the Noid Light helped find it. BTY, a rebuilt computer was only $75 at AutoZone and has lasted me the last 5 years.