96? lincoln accel problem
#1
96? lincoln accel problem
well, it's dads car so I am not positive about the year and engine size but I believe a 96 4.6L engine.
problem: when accel hard, car simply bogs down. When accel slowly, engine will follow accelerator just fine.
engine scan showed lean on left bank. no other trouble codes.
Not positive but I think I might hear a vacuum leak (didn't have a lot of time to check things out.) Dad's always in a hurry, that is why the poor accel is a big problem
anyway, any ideas would be great. Time together is limited and any ideas would help speed the dx and rx.
problem: when accel hard, car simply bogs down. When accel slowly, engine will follow accelerator just fine.
engine scan showed lean on left bank. no other trouble codes.
Not positive but I think I might hear a vacuum leak (didn't have a lot of time to check things out.) Dad's always in a hurry, that is why the poor accel is a big problem
anyway, any ideas would be great. Time together is limited and any ideas would help speed the dx and rx.
#5
nap - Any other symptoms that could be revealing? Gas mileage, misfiring, hard starting, anything like that?
Vacuum leak sounds feasible.
I think I would be wondering about fuel delivery maybe, too. Fuel filter changed recently? Wouldn't hurt to check fuel pressure.
In the good old days you would immediately suspect the accelerator pump in the carburetor. Nowadays that function is taken over by the computer using the various sensor inputs - MAF, MAP, TPS, etc - to determine that you need more gas delivered, but you're not getting any codes for a sensor problem. Puzzling.
Vacuum leak sounds feasible.
I think I would be wondering about fuel delivery maybe, too. Fuel filter changed recently? Wouldn't hurt to check fuel pressure.
In the good old days you would immediately suspect the accelerator pump in the carburetor. Nowadays that function is taken over by the computer using the various sensor inputs - MAF, MAP, TPS, etc - to determine that you need more gas delivered, but you're not getting any codes for a sensor problem. Puzzling.
#6
other symptoms: hunting for idle speed. It doesn't do it all the time and it only does it for maybe 15 seconds, if that, and then settles into a correct idle.
all in all, it actually runs pretty smooth. It's just that darn bogging on med-hard accel.
new fuel filter, plugs, air filter, not sure what else since my brother did that for dad.
when I get a chance, I going leak hunting (I hat hunting vacuum leaks, especially since I am getting older and it's actually harder to hear them)
all in all, it actually runs pretty smooth. It's just that darn bogging on med-hard accel.
new fuel filter, plugs, air filter, not sure what else since my brother did that for dad.
when I get a chance, I going leak hunting (I hat hunting vacuum leaks, especially since I am getting older and it's actually harder to hear them)
#8
I was thinking possible TPS as well. They often throw no codes since they are a variable input and as long as they read within parameters, they do not generally throw a code. That does not mean they are reading properly at any given position though.
The TPS is only about $30 so that may simply get a new one. The MAF is $130 so that may get some dx work prior to replace.
thanks again.
The TPS is only about $30 so that may simply get a new one. The MAF is $130 so that may get some dx work prior to replace.
thanks again.
#9
Nap... I'm thinking fuel filter or fuel pump,,, They can't keep up to the demand of heavy acell... Can you borrow or rent a fuel pressure guage??? If so,, Tape it to the windshield & go for a drive... Fuel delivery problems can very decieving... Roger
#10
fuel filter is new so that is out. I'll have to hunt up the pressure gauge. I know either dad or I have one somewhere.
Just so all know; I used to work as a mechanic in a life long ago (along with a million other occupations) and dad was a lifer industrial truck mechanic (lift trucks specializing in electrics. In fact, for fun he made an S10 electric truck conversion that I towed up to Michigan from Tennessee where he built it at a friends house. It doesn't have enough range to run from Tenn to Mi) We aren't newbies but as things progress, sometimes the cure is just not as obvious, and easy, as it once was.
thanks for all the help.
Just so all know; I used to work as a mechanic in a life long ago (along with a million other occupations) and dad was a lifer industrial truck mechanic (lift trucks specializing in electrics. In fact, for fun he made an S10 electric truck conversion that I towed up to Michigan from Tennessee where he built it at a friends house. It doesn't have enough range to run from Tenn to Mi) We aren't newbies but as things progress, sometimes the cure is just not as obvious, and easy, as it once was.
thanks for all the help.
#12
well, it seems a vacuum leak is not the problem. I looked and listened and fumbled around with everything and could find nothing. I pulled the plug to the idle air motor and the thing died instantly and when it was hunting, pulled it and manually ran the throttle and could get it to idle quite low so that tells me; no vacuum leaks.
guess it's time to start checking sensors but it has been so long, off to the library where we have Ford service manuals (factory stuff) which are quite complete in their processes of checks. It has been so long for me that I have forgotten how to check many of the sensors.
thanks for the ideas guys.
Oh, and kwick, the MAF is high on the list of sensors to check.
guess it's time to start checking sensors but it has been so long, off to the library where we have Ford service manuals (factory stuff) which are quite complete in their processes of checks. It has been so long for me that I have forgotten how to check many of the sensors.
thanks for the ideas guys.
Oh, and kwick, the MAF is high on the list of sensors to check.