won't start

Have a 97 gmc jimmy highrider, had problems starting since about a week after buying the truck. Recently wouldn't start, tried the obvious, spark, gas, fuses, etc. anyway was told the spider injeciton was bad. tore down no gas in the ports after removing plentum. tried pressure test on schrader valve, when ignition is on reads ten on gauge, when cranked it jumps up to 50 to 55, any way could get it to start once pouring gas done in the throttle body, would start fine for a couple of hours trying it once every so often. once sitting over night, nothing just cranking and not starting. was also told the regulator in the top of the injectors might be bad, I'm thinking fuel pump, any suggestions anybody?

buying the truck. Recently wouldn't start, tried the obvious, spark, gas, fuses, etc. anyway was told the spider injeciton was bad. tore down no gas in the ports after removing plentum. tried pressure test on schrader valve, when ignition is on reads ten on gauge, when cranked it jumps up to 50 to 55, any way could get it to start once pouring gas done in the throttle body, would start fine for a couple of hours trying it once every so often. once sitting over night, nothing just cranking and not starting. was also told the regulator in the top of the injectors might be bad, I'm thinking fuel pump, any suggestions anybody?

Finn,

If you are getting 50-55 lbs. pressure during cranking, I very much doubt it is the fuel pump. I'd be more inclinded to think the CP! injector block is the problem. If you are not getting fuel feed from any of the injectors it has to be something common to all the injectors, like a blocked passage in the inector block or no +12V to the injectors. That's the direction I'd take in troubleshooting the problem.

Those Central Point Fuel Injection systems are known to be troublesome, but I've only worked on a couple of them and both times it was a problem with just one cylinder not dispensing fuel (one was a bad injector and another was a stuck closed poppet valve on one cylinder line caused by using crappy gas).

Regards, Bill Bowen Sacramento, CA