Hey guys I need some help troubleshooting my 92 SC300 (237K). This past week I've had problems with acceleration where I would lose power and regain immediately...I would describe them as "hiccups" whether I was accelerating or cruising on the freeway. I also had one occaision where the it had a hard time cold starting.

I did some tests per the manual and thought that the fuel pump was at fault. I changed that out yesterday and thought it was running fine. But I find that I'm still having a problem with starting and the "hiccups" are now less severe.

Reading through the manual I jumpered the FP and +B connectors and the engine fires up immediately every time. Does this mean my fuel pump ecu is shot? I did replace my fuel pump ecu at about 200k but I did replace it with one from a junk yard. But my symptoms at that time where that when I started the car it would start fine but die immediately. This time it won't start at all.

Any help is appreciated!

UPDATE: I did the fuel pump ECU bypass trick and everything is running perfect!

 

ever think about the fuel filter?

 

Forgot to mention I changed that about 30k miles ago

 

 

well i know what you talking about, i had the same problem, i switched out the fule pump for a new one, and the fuel pump ecu also, and the fuel filter, the only thing is diffrent is that it can start up by itself now without me having to jump it, but the hiccup problem is still there. im working on it rite now if i find the problem today ill let youll know