Have 1990 with 4.3 TBI. How do I check the fuel pressure, and what should it be?

 

you need this guy right here
TBI Throttle Body Injection Fuel Pressure Gauge Adapter | eBay

plus the fuel test kit. hit up autozone etc. its totally free,but because of lowlife thieves,you have to leave a retail deposit. i think its about 100 bucks? Not sure. been a while.

 

It's more like $150-$160 for the deposit down here. But yeah, like chris said, you get it all back when you return it. Rotten thieves!

 

Thanks, any particular place that the adapter screws into?

 

Yep,right behind the throttle body.

 

thanks, what should the pressure be?

 

checked fuel pressure, between 7 and 8 psi. at idle. What should it be?

 

gotta be between 10-13. Best you can do is rebuild the throttle body,if its still low,its the pump. Buy whatever brand rebuild kit,but stick to ac delco on the pump. Unless you enjoy changing them every 2 months.


hint : to bump pressure a 1lb or 2,stick a quarter on top of the regulator spring before you reinstall it. google "quarter mod tbi". ive done it. made a difference.

 

since it is low, does that mean it is the fuel pump? I tested the pressure between the tank and the filter.

 

Ah! in that case. Yes pumps weak. Remember to buy only ac delco. You can get one from rock auto for 40 bucks. Cheaper then a aftermarket.