Ford problem?

Question

Ok, 1989 thunderbird...3.8 fuel injected. 124,000 miles.

Now the problem(s): i would call it a "stumble" but it isnt that dramatic...its more of a "delay" when i hit the gas. It is more evident when i am NOT trying to take off fast.It also takes a few trys to get it to start a lot of the time.

I take very good care of my car. A good word would be "meticulous". There are no fault codes or error codes of any kind. And almost everything is new under the hood. I got it with 98000 miles on it with a bad head gasket, and that has been fixed. I dont know what the problem could be, so if some one could throw out some "maybe"s, i would really apreciate it!

PS, could that be the fuel pressur regulator?

I have done a complete tune up, and a new fuel filter 2 days ago. I also took the upper intake manifold off and thoroughly cleaned all of the carbon out...because i thought that it might have been the problem.

When i tap the throttle, i can hear it suck air quite a bit sooner than the engine revs."quite a bit" is like a half second.

Answer 1

Usually on those models, when the regulator causes issues, it causes major issues such as heavy black smoke... those engines won't hesitate on a rich mix until at least 60 or so PSI I've found in the past. (fuel pressure should be 30PSI running at idle..40 on WOT)

But first step may be those fuel and air filters just to check...

Does this vehicle have a MAF or a MAP sensor?

I've seen both of them cause issues like this.. I want to say this one is a MAP sensor car.. you'll see a vaccum line heading off the engine to a square box with 3 wires coming from it... If this box isn't reading the air pressure right, it will give symptoms just like this, and was a known issue on these cars.

Some of the newer ones close to 1992 I think were the ones that had the MAF sensor (3 wire sensor in the intake line between the air box and the engine).. if it reads the airflow wrong ..same issue different part.. that's all (the MAP sensor was more forgiving than the MAF)

Also check your base timing..make sure you pull the spout and with it reading number 1 cylinder (that's the first one on the passenger side near the front of the motor).. it should be firing on 10 degrees BTDC...

Seen some where a bad ignition distributor cause this issue too but usually it comes with lack of power accross the band.

Hope this gives you some ideas on this EEC IV system.

Answer 2

The major tune up on the car needs checked first ...

it consists of the following according to the Chiltons labor Guide

clean battery connections, test battery, check intake and exhaust manifold mounting nuts and bolts, tighten/retighten to specs, Check engine compression, replace spark plugs (be sure all are correctly gapped too), test resistance of plug wires replace any bad ones, inspect distributo cap and rotor replace if necessary, if equipped check vacuum advance operation, check base ignition timing and idles speed, service aircleaner element and emission controls inspect and adjust all drive belts...

this specification calls for 2.1 hrs book time...

also make sure the fuel filter has been changed within the last 8,000 to 15,000 miles

even though your head gaskets were recently done do a compression check to ensure a good job was done and that a problem still doesn't exist in that area...

after this my best bet is that the problem is the crank position sensor toothed cog on the crank is partially dirty... clean it an the magnet pickup with carb cleaner and a rag ...

blowing it off with compressed air will also help... many a stutter and hesistation on Fords is from the crank sensor

Walt

Answer 3

Always start with the basics. In your case check the air filter and then the throttle body. Most people pay littel attention to the throttle body and spend all kinds of money on stuff that isn't needed.

When you clean the thottle body you have to do it properly and not just empty a can of throttle body cleaner in it and assume this will work.

The oil vapors get sucked in via the PCV and breather hose and they will then solidify inside the cool throttle body just past the throttle plate.

You have to spray a clean rag with throttle body cleaner and then hold the throttle plate open and wipe the interior of the throttle body out and the back side of the throttle plate. Keep wiping until the rag comes out clean and the only thing you see is clean aluminum with no black goop on it.

Hope this does it. You have to use throttle body cleaner and not carburetor cleaner as the carburetor cleaner will melt some of the sensors and damage seals.

Good Luck!

Answer 4

Fuel filter, spark plugs and wires are a good place to start if its been over 18K miles. It is likely caused by a small vacuum hose that was left off or put in the wrong place when it was last repaired, Check the hoses first, if it did not do it before the repair then it should not start doing it after.
Good Luck and GOD Bless

Answer 5

Replace the IAC valve located on top of the intake manifold. It has a bellows inside that usually tears. Be sure to get a new gasket,too.

Answer 6

Sounds like its not getting enough fuel to start or get going. Could be the regulator or the fuel pump.

Answer 7

Could be that or it could be it needs new spark plugs/wires.