Hit gas bogs down

[blkfordsedan]

Sounds like a fuel issue (lack of) to me. Since it runs good on start-up when the EFI is running rich (warm-up mode), I would swap the ECU and any other sensor related to the fuel system that is on the actual car and didn't get swapped in the motor exchange. I would have to research, but isn't there a MAP or air temp or density sensor or something that is mounted to the firewall? Time for a Haynes manual!

[Papabug]

Did you use the intake and throttle body from the old engine? Could be the butterfly in the throttle body isn't opening all the way. Or as someone before stated O2 sensor..

[GenevaDirt]

Did you use the intake and throttle body from the old engine? Could be the butterfly in the throttle body isn't opening all the way. Or as someone before stated O2 sensor..

as stated....EVERYTHING that is attached to the engine stayed attached to the engine when it was taken from and excellent running Festy and dropped into this car. Wiring harness and ecu are about the only things that were not transferred over.
Car had this same problem with previous engine that was installed....took that one out and put in new engine....start new engine....same issue.....

[ericsmith32]

Well as I know not all electronics are made the same.. anybody that works on computers for a while would testify to that. The ECU from the other car may or may not been as sensitive on a particular sensor or a series of them.. this one could be too sensitive. I'm still thinking it's the o2. How did the gas mileage compare on the car you pulled it from compared to the new? I can tell you one of my dad's car get better mpg than the other. Timing and all the parts are the same the old difference is the one that gets the better mpg has ac.. you'd think it'd be the other way around. There's always the fluke car running around.

[GenevaDirt]

Well as I know not all electronics are made the same.. anybody that works on computers for a while would testify to that. The ECU from the other car may or may not been as sensitive on a particular sensor or a series of them.. this one could be too sensitive. I'm still thinking it's the o2. How did the gas mileage compare on the car you pulled it from compared to the new? I can tell you one of my dad's car get better mpg than the other. Timing and all the parts are the same the old difference is the one that gets the better mpg has ac.. you'd think it'd be the other way around. There's always the fluke car running around.

the NEW (used from known good running car) engine is running the same as the old engine and the o2 sensor was tried 3 different times with no change.

Not saying it is not the o2 sensor but from all that I know has been tried I would say it is not.
I am guessing ecu still, at this moment, since it is one of the only things that has not been changed.

[blkfordsedan]

It sounds like when it goes into closed loop mode it's not getting enough fuel. The creeping idle may be a result of a lean mixture and when you open the throttle it is not giving it the fuel enrichment it needs. I would start by changing the ECU and then go to any sensors that stayed with the original car. I would think if it was a sensor it would throw some kind of a code to the CEL.

[TONYCASH]

Cel?

[blkfordsedan]

Cel?

Check Engine Light

[TONYCASH]

Check Engine Light

LOL.Thanks.

[FB71]

Tony, got your PM. Here's my thoughts;

You have a fuel starvation issue. The reason it idles higher (and sometimes creeps up) is the same reason it falls flat when you try to accelerate; its going lean from lack of fuel. My guess, since it starts and runs fine at first, but seems to develpo the problem as it warms, actually has nothing to do with engine temp. As the fuel pump runs, it collects debris from inside the tank, and gradually restricts the sump. The problem then becomes noticeable about the time the engine reaches operating temp. When you shut off the vehicle/pump, the debris floats away from the sump, permitting reasonable fule flow for the next start.

I had this exact issue with a Taurus years ago. The vehicle tank was full of silt from a contaminated fueling station tank. It would gradually clog during the first few minutes of driving, ulimately rendering the vehicle powerless, to the point of stalling. Sitting for a few minutes would temporarily clear the problem. Any rocking of the car, while off, would yield a greater time before a repeat failure.

Open your tank, and I bet you will find some nasty crud floating in the bottom.

[ericsmith32]

Sorry I guess I didn't read the part where you changed the o2. ECU sounds like a good start. I just recalled my dad said it's still jumping on take-off never figured that one out. We have a spare ecu though I'll try. Can't help you but I bet whatever it is is simple and probably make you cuss when you figure it out! lol

[TONYCASH]

Tony, got your PM. Here's my thoughts;

You have a fuel starvation issue. The reason it idles higher (and sometimes creeps up) is the same reason it falls flat when you try to accelerate; its going lean from lack of fuel. My guess, since it starts and runs fine at first, but seems to develpo the problem as it warms, actually has nothing to do with engine temp. As the fuel pump runs, it collects debris from inside the tank, and gradually restricts the sump. The problem then becomes noticeable about the time the engine reaches operating temp. When you shut off the vehicle/pump, the debris floats away from the sump, permitting reasonable fule flow for the next start.

I had this exact issue with a Taurus years ago. The vehicle tank was full of silt from a contaminated fueling station tank. It would gradually clog during the first few minutes of driving, ulimately rendering the vehicle powerless, to the point of stalling. Sitting for a few minutes would temporarily clear the problem. Any rocking of the car, while off, would yield a greater time before a repeat failure.

Open your tank, and I bet you will find some nasty crud floating in the bottom.

Well "the mechanic" my mom took it to ran through
some kind of cleaner.???? I guess it is possible.

[wybnrml]

I have had the same problem as you mine is a 90 Automatic and have followed your thread since you posted it the first time hoping you would figure it out on your car so I could fix it on my car. I have done the same stuff as you have like coil, timing, MAF etc.
I droped the fuel tank on mine and no rust or crud and blew the fuel lines out and it didn't fix anything so I don't think that is it.

[Kofkof_00]

Similar to fb71, rust in the gas tank? Fairly common with 15+ year old cars.

I am batteling the same issue as we speak. I'm going to try a new OC sensor. (once I figure out where it is located)

...Goes back to his haynes manual...

[ericsmith32]

I'd spray the o2 sensor with some PB Blaster for a couple days before you try to remove it.. you might cuss otherwise.