Ranxeroxlubna
Member
- Joined
- December 30, 2014
- Messages
- 38
- Reaction score
- 1
- City, State
- Miinneapolis
- Year, Model & Trim Level
- 1998 Mercury Mountaineer
This is a repost.
Initially, the hesitation began just at the start up. Wait a second and it would smooth out and no problems.
2 days ago the following happened.
Could it be the fuel pressure regulator?
Here is the information from the diagnostic tool:
Fuels sys 1 - CL
Calc LOAD% - 28.6
ECT F - 188 DEGREES
STFT B1% - 10.1
LTFT B1% - 25.0
STFT B2% - 13.2
LTFT B2% - 25.0
ENG RPM - 675
Veh Speed - 0
IAT F - 69 DEGREES
MAF lb/mn - 0.474
TPS % - 17.6
02S B1 S1 V - 0.425
STFT B1 S1 % -8.5
02S B1 S2 V - 0.670
STFT B1 S2 % -NA
02S B2 S1 V - 0.730
STFT B2 S1 % - 12.5
02S B2 S2 V - 0.770
STFT B2 S2 % - NA
OBDSup - OBD2
This is an average out of 5 frames in memory.
Initially, the hesitation began just at the start up. Wait a second and it would smooth out and no problems.
2 days ago the following happened.
- Motor died on the road.
- Repeated attempts to start it resulted in a stuttering idle, bucking, and the motor stopped running.
- After restarting the motor, if you work the throttle and let the engine spool up, it would accelerate up smoothly to wide-open throttle.
- If you open the throttle all they way suddenly, you get backfires in the manifold and the hesitation and stuttering really go nuts.
- I drove it home after clearing out whatever was involved, it stuttered and hesitated all the way home, but it got there. I put it in neutral at the lights and revved it up to keep it going.
- I sprayed starter fluid on all the vacuum connections with no change to the idle.
- I pulled the spark plug cable off the coils, one at a time; the front row caused major changes to idle, the back row did not seem to have as much of an effect, less as moved from 3-2-1.
- I disconnected the MAF connector and it did have a very subtle effect.
- I disconnected the intake hose at the throttle body and it ran a bit better, although moving the throttle manually repeated the aforementioned problems.
- When I reconnected the intake hose to the throttle body, it just died.
- I get no codes.
- The computer seems to struggle to connect with the diagnostic device.
- I cleaned the MAF in late summer.
- Before I changed the fuel filter, I checked the Fuel Pressure, which is at 24 PSI, dropping down to 21 PSI if you accelerate.
- I changed the tank, the fuel pump and the gas lines in February of 2014.
- Fuel filter replaced - Gas clear - EFI pressure still at 24 PSI, but doesn't dip.
- Poured 2 cans of Sea Foam into a full tank and left it running for 30 minutes. Took it out on the highway and it ran okay at the start, ran better as it cruise home.
- Stutters and staggers with cold start
- Idles smoother, no stalls as it warms up
- Will spool up to 3k RPM, then catches a bit, then spools up to 5500 RPM.
- Accelerates fine.
- Will run smoothly at highway speeds
- Pressure still at 24-25 PSI when I checked upon return home.
Could it be the fuel pressure regulator?
Here is the information from the diagnostic tool:
Fuels sys 1 - CL
Calc LOAD% - 28.6
ECT F - 188 DEGREES
STFT B1% - 10.1
LTFT B1% - 25.0
STFT B2% - 13.2
LTFT B2% - 25.0
ENG RPM - 675
Veh Speed - 0
IAT F - 69 DEGREES
MAF lb/mn - 0.474
TPS % - 17.6
02S B1 S1 V - 0.425
STFT B1 S1 % -8.5
02S B1 S2 V - 0.670
STFT B1 S2 % -NA
02S B2 S1 V - 0.730
STFT B2 S1 % - 12.5
02S B2 S2 V - 0.770
STFT B2 S2 % - NA
OBDSup - OBD2
This is an average out of 5 frames in memory.