|
"Hello, I have a '93 volvo 940 wagon Regina with 161,000 miles in near mint condition.
Problem:
After a period of heavy stop and go traffic driving (in the city) - from a complete or rolling stop, when I give it throttle, it does not accelerate/respond and feels as if it is 2nd gear not 1st as it moves forward or not getting enough gas or air. After a about 5 seconds with the pedal at full throttle it begins accelerating and shifting normal while driving. Also, IT DOES NOT OCCUR at all while driving at speed in all gears once beyond initial acceleration (drove a 2000 mile trip - not even a hiccup on the highway). As soon as I hit the city in stop and go driving (engine hot) the symptom returned.. It seems significantly more pronounced when the engine is hot (as if some hose or wire is overheating/collapsing). IT NEVER STALLS out but idle limps rythmically between 200 to 700rpms like the ECU is keeping it from stalling out then stablizes around 600 for a period then limps again. Symptom occurs about 7 out of 10 "in city" accelerations.
OBD codes - recurring 2-3-2 fuel code (cleared several times and reset/ swap ECU and all repairs below) all other ODB codes 1-1-1. NO CHECK ENGINE LIGHT.
Attempted solutions: none of the following affected the symptom one way or the other.
all vacuum hoses - OK
clean/serviced throttle body all air intake system - smoked for leaks - OK
cleaned/tested IAC - OK
installed correct Regina O2 sensor checked all connections - OK
replaced MAP sensor - OK
replaced Regina FPR - OK
swapped ECU with known working ECU - OK
sent injectors in for testing and cleaning / re-installed- OK
serviced PCV system (even replaced breather box) - OK
replaced RPM sensor- OK
replaced ATS (in air intake hose) - OK
checked/replaced TP switch / checked idle - OK
replaced ETS on block (car not overheating and reading correct temp) - OK
tested/swapped FP relay- OK (seams a bit hot to touch but it wouldn't crank if shorting)- OK
new rotor,cap,wires and ignition wire plus 1-1-1 on ignition ODB - OK
Did not test/suspect the fuel pump because a new one was put in by a trusted mechanic about 1 year ago with new fuel filter. Also new brake booster with hose and check valve installed(since pic) no leaks detected.
I'm going to test the fuel pressure tomorrow at the rail and in-line just in case FPR or pump has failed. Could it be a Bosch pump in there causing havoc ?
Transmission and electrical next (all grounds seem to be ok) but you never know.
Anyone have any thoughts ? 1 volvo specialist and 3 other mechanics have failed to diagnose and solve this problem so far....
No oil or coolant leaks and I assume/hoping the head gasket is still in good shape.
Thanks everybody for taking the time to read this lengthy post, I thought I would save a lot of time with answering obvious questions first.
Best,
Schumi1
|
