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1993 Ford Thunderbird, acceleration issues..

10184 Views 9 Replies 6 Participants Last post by  slingshots
First off I would like to say hello to everyone! Seems like an awesome forum. I'm pretty new to Fords and cars in general (only 17 years old).

Ok so here is the problem. I have 93 T-Bird thats got no 'get up and go'. She's a 3.8 V6 and the problem is that at full throttle she'll do 3000 RPM's at best. However in idle I can rev her all the way up to the 6000's.

Here is what I know/what I've done:

-The Check Engine Light is NOT on
-O/D Was slipping so I installed AOD-HP Shift kit from TransGo (did it all by myselft :D )
-Tranny Flush/new filter
-Replaced Spark Plugs/Spark Plug Wires
-Oil changed (nothing milky, so head gaskets are good)
-Ran injector cleaner through the lines and all injectors are operational

Any ideas? Any help would be greatly appreciated. Oh and I don't know the mileage. The dash is stuck at 180xxx.

Also, how much power can you crank out of the Essex 3.8?
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First you need to dump the codes. Being a '93, it should be an EEC system-which allows a user to dump the diagnostic codes without a scanner. You need a piece of wire, a paperclip, piece of mig welding wire, anything that will conduct electricity. has the instructions how to do that. It's geared toward a Mustang but same principles apply...locations may be different though.

Just because the CEL (check engine lamp) is not on doesn't mean that nothing's wrong. The computer stores codes too for I believe 50 drive cycles. Might be 100. Many times dumping the codes will give a clue as to what's going on...I do it about once a month just to keep a watch on things.

2nd...keep in mind that a 3.8 isn't anything to write home about, especially in a heavy thunderbird. I think a 4 cylinder Mustang is faster. Well maybe not but it's a close race.

Mods...there's some things you can do, but the heads just don't flow much air so a head change is usually in order to open them up. 4.2 trucks and 3.9 Mustangs had dual port heads (split port) and intakes...they are the hot ticket for stock Essex performance. Then you're going to get into exhaust, intakes, blowers and turbos with the latter two being enough to blow the block to smitherines...or at least bust the crankshaft and lift the heads.

Surprised your current 3.8 hasn't lost a gasket yet. Impressive! 99% of them leak coolant into the engine with that many miles on them.
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2 things to try...

Replace fuel filter.

Try unplugging mass airflow sensor. The car will still run with it disconnected. The check engine lamp should come on and it may stumble a bit but with MAF disconnected the PCM uses throttle position sensor and rpm to determine the right amount of fuel. If you're able to pull more RPM with the MAF unplugged then it is likely bad.
Welcome to the forums! These guys have it covered, and as you gather more info, we can help get more results. If you're serious about more power from your 'Bird, there are popular swaps that will net more performance per dollar and labor hour than twisting the nipples on the 3.8L. We can get this one going for a daily driver, and then you can analyze what direction you want to go for performance.


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Oh yeah, and free revving this motor "into the 6000's" really isn't a good idea. :eek:

"twisting the nipples" :D:D:tup:
I disconnected the MAF (engine light ON) and it did pull much better without it. shifting from second to third gear at full throttle was a much heartier 3600 RPM's. So that means I should get a new MAF sensor? And is 3600 good? Hehehehe what can I say? Nipple twisting is fun :D :D :D

I'll probably be checking the codes later on this week and post my results. I was thinking that maybe after saving up some money I'll go for the Stage 3 Power Pack from It seems to be very comprehensive and many forums I've visited recommend it. As for my gaskets, I'm just as surprised as you are. The guy I bought it from was kinda creepy so I was expecting it to have some problems but it drove all 30 miles back to my house. Still running strong :)
I disconnected the MAF (engine light ON) and it did pull much better without it. shifting from second to third gear at full throttle was a much heartier 3600 RPM's. So that means I should get a new MAF sensor?
yep :tup:. it should run even better with a good maf.

btw... 3.8's in rear drive cars seemed to not have nearly the head gasket problems that fwd taurus\windstars did. dont know why.
Head gaskets in rwd 3.8 is pretty common, about every 100k-120k. if your head gasket is going it most likely won't show up in the oil. I have had this happen 3 times on two different engines, it will start to use coolant. this will go on for a long time. If you drive it long enough it will end in a big puff of white smoke. No noticable loss of power untill they blow out. Never saw any evidence of water in the oil. Other than the head gasket thing they are great little engines. I have one with 260k, it has had two sets of head gaskets and a set of injectors other than that just small stuff and it still runs great. The little 3.8 is short on performance, If you really want more power you would be better off to buy a V8 car or a newer sixer (ie an 11 stang). With a mild V8 you could get twice the power and the same mileage of the 3.8. That being said, I did build a 3.8 mustang with some supersix stage II stuff. It ran pretty well and I used the smaller of their cam choices and my stock converter in the AODE. Also went to 3.45 gears. For reference if I had a manual trans and the next step up cam I could probably have kept up with a stock GT. In short getting HP out of the 3.8 expensive, but possable. If you have your heart set on building the 3.8 swap out your gears first, no less than 3.73s, or you will be dissapointed. Especialy with the stage III stuff.
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Hi Guys,

I literally just purchased a 93 Thunderbird from the original owner with 79k. It has had all its server from a dealership. the owner went into a nursing home and its been sitting the last 6 years. I have the same problem as described. Revs all day in park. Put it in Drive and she just doesn't wanna do anything. I am going to try this little test and see how she does. Clear car, no leaks, and im super excited about owning her. I know they are nothing special but ever since I was a little kid growing up in the 80s, I have wanted one of these 90's style Thunderbirds.

The other mistake I made, I got her home. Drove 76 miles and stopped to get a car wash when I got home. I forgot about the antenna. that thing ripped right off. Have that on my list now :)
Just a quick update. I unplugged the mass airflow sensor and power was instantly better. I went across town and found a replacement. Works like a champ. Loving this old car.
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