fuel I think Options

[driver66]

damn car, I was cruising and happy,then i developed a miss in my1.7. so I kept driveing and it jumped out of it ,then back and forth. so I get home and throw in a new set of plugs and cap. [local parts store has the rest ordered] and fire it back up and off i go to work , no fix...so i figure its my injector cutting in and out. at lunch i wiggled some wires to see if it could be a bad connection . after work i jump in to come home and she would not do anything but turn over ,the fuel pump would not come on . so we pulled it in with a damn ugly s-10 and set ever sence......3 days ...............help me please find this problem

[garyh]

1) Does the fuel pump run when you first turn the car on? It should run for 5 seconds when you move to key to on. The center relay on the panel behind the driver's head is the pump relay.

2) If it does, is it making the correct pressure? (A -good- pressure gauge is $20. Everyone should have one.) 30~32 PSI, IIRC.

If the pump doesn't spin, it's an electrical problem, or a bad pump. If it does spin, but can't make pressure, it's a bad pump, a clogged fuel filter, or a bad pressure regulator. If the pressure is too high, it's a bad regulator, or a crimped/clogged return line.

Heck, it could even be a clogged screen in the bottom of the tank. (Which will eventually kill the pump. BTDT)

After you can say yes to 1) and 2) above, you can start looking for blown injector drivers (very rare), bad FI points (almost as rare) or clogged injectors (quite common).

A quick test for clogged injectors is to up the pressure to 40~45 PSI. If it starts running "better", you have clogged injectors. Do not leave the pressure that high; fix the problem, and set it back to normal.