98 camry 5sfe

[Charlie Smith]

1998 camry 5SFE 80K miles, occationaly hesitates and sputters on accelaration. I ran a OBII live check and discovered that the ST FTRM was about -20% during an episode of sputtering. It occurs often when there is a slight load on the the vehicle ie. a hill. It will return to normal if I open the throttle, but sometimes it will backfire which I do not want to happen for obvious reasons. I visually checked the vacuum lines on the manifold and found no glaring problems. I do not have a fuel pressure gauge or a hand vacuum tool so I did not get that test done. My research points to a possible faulty fuel pressure regulator. Is it worth purchasing a new fuel pressure regulator? They run from 50 to 120 dollars. Wonder why the wide range of price? Do they fail often? Any Suggestions??
Thanks

[chronoti]

dont really hear of failing fpr's, also look at sticking injectors

[Toy_Dreamer]

Originally Posted by Charlie Smith

1998 camry 5SFE 80K miles, occationaly hesitates and sputters on accelaration. I ran a OBII live check and discovered that the ST FTRM was about -20% during an episode of sputtering. It occurs often when there is a slight load on the the vehicle ie. a hill. It will return to normal if I open the throttle, but sometimes it will backfire which I do not want to happen for obvious reasons. I visually checked the vacuum lines on the manifold and found no glaring problems. I do not have a fuel pressure gauge or a hand vacuum tool so I did not get that test done. My research points to a possible faulty fuel pressure regulator. Is it worth purchasing a new fuel pressure regulator? They run from 50 to 120 dollars. Wonder why the wide range of price? Do they fail often? Any Suggestions??
Thanks

I have the same problem, but I intend to put a bottle of Lucas fuel tune-up in a bottle:
http://www.lucasoil.com/products/dis...catid=2&iid=26

..and not take the big route and take it in somewhere to have them fix it just yet.

[deadrx7conv]

How old is the fuel filter?

[fenixus]

Originally Posted by Charlie Smith

1998 camry 5SFE 80K miles, occationaly hesitates and sputters on accelaration. I ran a OBII live check and discovered that the ST FTRM was about -20% during an episode of sputtering. It occurs often when there is a slight load on the the vehicle ie. a hill. It will return to normal if I open the throttle, but sometimes it will backfire which I do not want to happen for obvious reasons. I visually checked the vacuum lines on the manifold and found no glaring problems. I do not have a fuel pressure gauge or a hand vacuum tool so I did not get that test done. My research points to a possible faulty fuel pressure regulator. Is it worth purchasing a new fuel pressure regulator? They run from 50 to 120 dollars. Wonder why the wide range of price? Do they fail often? Any Suggestions??
Thanks

negative fuel adjustment looks like engine is not getting enough air for proper mixture. have you checked/replaced the air filter recently?

is this car a California emission specs? if so then until '99 (inclusive) there is also an Air Assist tube going from bottom of IAC valve (below Throttle Body) and plugged into the engine head between fuel injector 2 & 3. make sure there is no cracks/restrictions in that tube.

IAC valve itself might be a problem too (dirty/sticky), restricting the air flow at slightly open throttle plate, or throttle plate itself might be sticky on edges.

FPR problem is very rare, same about fuel pump. but do check the fuel pressure at idle if you have time and the gauge. Fuel Pressue Norm is 44-50psi at ACC ignition (I think same should be at IGN ON when fuel pump works), should hold value for 5 mins (min 21psi) and show same value at idle.

I actually have the opposite problem, my fuel trims tend to go into strong positives at idle, looking like engine is getting some unmetered air from somewhere, but it fluctuates, sometimes looks perfect (+4% LTFT at idle) and some other time is bad (up to +14% LTFT at idle). almost impossible to find the root cause.