FUEL PUMP WAS CHANGED 2 MONTHS AGO. CHECK ENGINE LITE ON, FUNNY SMELL AFTER SHUT OFF ENGINE. TAKE IT TO SHOP IN STREET CORNER. REPLACE OXYGEN SENSOR, REPLACE WORN HEAD GASKET. CHECK ENGINE LITE STILL ON AND FUEL PRESSURE GOES UP AND DOWN WITH BLACK SMOKE OUT TAILPIPE. SHOP STILL CAN'T FIGURE OUT WHAT GOES WRONG. COULD IT BE THE ECU OR IS THERE A MALFUNCTIONNING FUEL PRESSURE REGULATOR??? NEED HELP !!!

 

Could be a bad fuel pressure regulator.It could also be a bad mass flow sensor.Or a very bad vaccum leak.
Or even maybe the coolant temp sensor.

 

hi tech,

They replace the fuel regulator and clean the return hose, but its the same reading. Suppose it s/b 42#, it is running at 80-100# even when the engine is not running. The fault code is 113 and 213 pointing to the fuel system, fuel injection. According to them, ECU, MAF, coolant sensor, vacuum are all okay. Everything pointing to the fuel pump which is replaced 2 months ago. Could this be the pump problem? The pump is either working or not working, how to test it.


Thanks again.

 

There is a possiblity the pump is bad.I forget it your car has a port to measure fuel pressure by the filter or not.If there is always a high fuel pressure then the pump might be bad.

 

Took it back to the Volvo specialist who installed the fuel pump, they checked the fuel pressure between the regulator and fuel injector. It was 34psi. They say fuel pump is not a problem, they also reset the check engine lite. The check engine lite stay off after ignition. How can the corner shop measured 80-100 psi?

But the engine shakes a lot, they suggest the valve need to be adjusted, so does the throttle lean/rich setting. Back home, discover that AT fluid is dripping from the transmission from the top, need to take it back to the corner shop. Any suggestion?

 

Are you sure the head wasn't bad.If the valves need to be adjusted they should have done it when they did the gasket.Did they have the head checked when it was off?

 

They farmed out to have the head rework, and I guess they check it there. Isn't true that compression test will show something?

BTW, as of late yesterday, they still could'nt find any wrong. They checked all the valve adjustment, timeming mark alignment etc... they are sure that the problem is not from the mechanicals in the head/valve. They checked the fuel flow is around 40psi, but the check engine lite goes back on, same codes as before 113,213. They suggested that ECU and/or MAF is at fault. Any lead?

 

Are you sure they have the throttle position sensor adjusted properly?If it is off it will cause it to run rich.You could also unplug the mass flow sensor and start it and let it idle and see if it idles better.It will set the light but it will tell you if the mass flow is bad.

 

Hi tech,

Shop finally get a rebuilt ECU and plug it in and everything is cool. No more shaking, check engine lite off and I am $400 poorer
They charge me only 400 on good faith. Thanks for your help. I will tell you the AT leak in the other subject.

 

Im glad you finally got it going properly.