The cars been giving me some problems lately. At first it didnt start up, ended replacing the fuel pump, fuel filter, and the fuel pump relay before figuring out it was the oil pressure sensor. THen i took it out and it drove great until it stalled on the packed vegas boulevard. It seemed to be a bad fuel pump as it was running extremely rich and blowing tons of black smoke. Driving it home fouled up all my plugs and as soon as we parked it at the house all the fuel leaked out of the evap canister.
So we replaced the fuel pump again along with the cap, rotor, coil and wires and it seemed to idle good blowing no black smoke until we took it out for a spin and now it keeps bogging and stalling during acceleration.
Before we take it to a shop anybody have any ideas what it can be?
maybe fouled injectors, cts, iat?

 

Have you placed a Fuel pressure gauge on the rail and tested if it's holding pressure? Next thing I would check would be the Fuel pressure regulator. Black smoke is definitely not good but is indicative of alot of fuel being dumped a.k.a an overly rich condition. If you put the fuel pressure gauge on it and turn the key to initial key-on positon and it holds pressure it's not your pump. If it drops pressure to 0 within a few seconds then you could have a leaky injector(s). With the fuel pressure gauge still on the rail tape the gauge to the windshield, go for a drive around town, and have a buddy watch the pressure gauge for sudden spikes or drops while driving. That will be indicative of a bad FP regulator.


HTH,

Brian P
89 IROC-Z 355

 

An overly rich condion will not b e caused by a bad pump, due to the fact that the FPR regulates the pressure coming from the pump down to 12-13 PSI (in a TBI application ) regardless if its 75 or 20 incoming.

You need to figure out what part of your fuel system is dumping so much fuel, but i assure you it is not the pump.

 

Agreed Bort62. Bad Fuel Pressure regulator or Leaky/Stuck open injector is probably the case.

Stick a scantool on it and see what the 02 sensor is seeing...probably 1000mV's.


Brian P
89 IROC-Z 355