97 LX not shifting into 3rd

[mysterymau0521]

My 1997 LX 4.6L just started not shifting into 3rd gear. it will go through 1st and 2nd gear but it wont shift out of second even when the revs are at the limiter. if i let off the gas it will shift into 4th but if i coax it down a gear it acts as it its in neutral and the gas pedal just revs the engine.

also it intermittently misfires on cylinder 4 and I have no idea why. I took it to the mechanic and they dont know why. New spark plugs, new wires, new coil packs, new computer.
Also when it misfires it shifts really badly and just jerks down into the gear it should be in

 

[theterminator93]

Could be a bad direct clutch. I also postulate that the misfire may not actually be a misfire, but torque converter shudder due to either burned up trans fluid or a burned up TC clutch. Either way I'd say it's rebuild time...

 

[mysterymau0521]

Could be a bad direct clutch. I also postulate that the misfire may not actually be a misfire, but torque converter shudder due to either burned up trans fluid or a burned up TC clutch. Either way I'd say it's rebuild time...

why would that read as a "P0304" code then? also my transmission has less than 100k on it. also when I hit the gass sometimes i can hear a distinct pop in the engine bay

And, I have put less than 10k miles on it, I had it serviced when i got the car because the previous owner hadnt sealed it right when he installed it and they said they resealed and serviced the transmission

 

[Grog6]

Idk about the codes, but the direct clutch is shot. misfire on 4 is likely a problem with that cylinder; see if the heater hose on the manifold right beside it is leaking into the spark plug hole.
You'll need to rebuild a transmission.

 

[MadMikeyL]

For the misfire, one of the first things I would do is get your factory coils back and swap them back. The factory ones literally never go bad, and all the aftermarket ones are problematic junk. As for what is causing the misfire, first step is a compression test. If that cylinder is low on compression, you have an internal engine problem. If not, check for spark at the plug. If you have spark, it could be a bad injector, or a bad computer hanging the injector open. Listen to the injector with a stethoscope or a long screwdriver to see if it is clicking. If not, swap it to another cylinder and see if the problem moves or stays on that cylinder.

 

[mysterymau0521]

Could be a bad direct clutch. I also postulate that the misfire may not actually be a misfire, but torque converter shudder due to either burned up trans fluid or a burned up TC clutch. Either way I'd say it's rebuild time...

Is it still okay to drive short distances like this? will that damage more?

 

[theterminator93]

Sorry, I speed-read your OP and missed the detail about the cylinder 4 misfire code. Yes, it wouldn't be old fluid or shudder - double check to be sure the plug well isn't wet with coolant; an intake manifold coolant passageway mates against the head there, and the heater core outlet from the manifold is also known to crack/leak after time.

If you're driving at modest speeds over short distances (I'd say speeds under 40 MPH for local trips of a few miles) I think you should be safe.

 

[Kenz]

If it's misfiring badly the catalytic converters can potentially get damaged. Probably best to drive it as little as possible until you get it sorted out.

 

[mysterymau0521]

Sorry, I speed-read your OP and missed the detail about the cylinder 4 misfire code. Yes, it wouldn't be old fluid or shudder - double check to be sure the plug well isn't wet with coolant; an intake manifold coolant passageway mates against the head there, and the heater core outlet from the manifold is also known to crack/leak after time.

If you're driving at modest speeds over short distances (I'd say speeds under 40 MPH for local trips of a few miles) I think you should be safe.

thank you, would a 2001 mustang GT intake manifold work? if you remember me, I swapped in that engine a while ago

If it's misfiring badly the catalytic converters can potentially get damaged. Probably best to drive it as little as possible until you get it sorted out.

its only misfiring intermittently and neither I nor the mechanic I go to knows why

 

[Grog6]

A2001 is a pi intake; you swapped a pi motor, and not the intake?

 

[mysterymau0521]

A2001 is a pi intake; you swapped a pi motor, and not the intake?

what are the differences between the pi and the npi motors?

 

[Grog6]

There's a lot. I'd suggest starting with google, and reading the modular motor entry in wikipedia.

 

[theterminator93]

Main differences - larger piston dish, smaller combustion chamber in the head, larger intake port in the head/different shape, more aggressive cams, longer intake manifold runners. Altogether worth ~35-50 HP over the NPI design, depending on application.

 

[mysterymau0521]

Main differences - larger piston dish, smaller combustion chamber in the head, larger intake port in the head/different shape, more aggressive cams, longer intake manifold runners. Altogether worth ~35-50 HP over the NPI design, depending on application.

is any of it stuff i can visually identify?

 

[LukesCougar]

is any of it stuff i can visually identify?

The intake itself (which could be a mod of its own and nothing else done) is the most obvious.

Pi intake on the right.

genuine ford pi intake left / doorman pi intake right.

Pi heads will have bigger ports too

The pi intake swap is still an option if you want to use a 2001 gt intake but requires a bit of rtv and some other gt parts..

 

[mysterymau0521]

The intake itself (which could be a mod of its own and nothing else done) is the most obvious.
View attachment 11144
Pi intake on the right.
View attachment 11145
genuine ford pi intake left / doorman pi intake right.

Pi heads will have bigger ports too

The pi intake swap is still an option if you want to use a 2001 gt intake but requires a bit of rtv and some other gt parts..

I still have most of the parts that came off of the mustang engine. can i send you pictures of both intakes i have and see if you can tell the difference? I cant really see one, they look very similar

 

[LukesCougar]

I still have most of the parts that came off of the mustang engine. can i send you pictures of both intakes i have and see if you can tell the difference? I cant really see one, they look very similar

Sure. I just read that you swapped in an 01 gt engine and not just the parts. In that case the pi intake install should be pretty straight forward and no rtv required if u have pi coolant passages/ ports. I am curious though how putting an npi intake on pi heads went if that's what happened.

 

[theterminator93]

If you truly installed a PI engine without getting a tune, it will not run optimally due to different spark tables (different combustion chamber design and compression ratio). It's also worth considering this as a contributing factor to the #4 issue. If it was wholly an issue with the programming you'd see issues on all cylinders, but if a mechanical aberration is present for #4 it would make a misfire all the easier to trigger with the stacked (potential) complications.

 

[mysterymau0521]

If you truly installed a PI engine without getting a tune, it will not run optimally due to different spark tables (different combustion chamber design and compression ratio). It's also worth considering this as a contributing factor to the #4 issue. If it was wholly an issue with the programming you'd see issues on all cylinders, but if a mechanical aberration is present for #4 it would make a misfire all the easier to trigger with the stacked (potential) complications.

This was my original post if you want to look at it: https://forum.birdcats.com/threads/2001-mustang-gt-4-6-vs-1997-thunderbird-lx-4-6.588/#post-12851

I also did replace the computer but since i replaced it with a Tbird computer the tune is probably still for the Npi engine?

 

[theterminator93]

Indeed it is.

What's the full rundown of what original T-bird parts you kept with the swap, and which 01 GT parts are on the car now? Engine, wiring, injectors, MAF, computer etc.?

 

[mysterymau0521]

Indeed it is.

What's the full rundown of what original T-bird parts you kept with the swap, and which 01 GT parts are on the car now? Engine, wiring, injectors, MAF, computer etc.?

everything that isnt the engine is t-bird. We couldnt use some of the mustang parts because it was manual

 

[theterminator93]

OK, that makes sense because it would probably not have wanted to run with the Mustang MAF on the T-bird tune.

The spark tables between PI and NPI are "close enough" for it to run, but they're still not ideal for the long-term. Getting the tune adjusted should be on the short list since it's been about a year since the swap, from what it looks like.

Have you checked the area around cylinder #4 for any signs of coolant? How old (and of what brand) are the plug wires? #4 may be intermittently opening up causing a weak or intermittent no-spark condition.

 

[mysterymau0521]

OK, that makes sense because it would probably not have wanted to run with the Mustang MAF on the T-bird tune.

The spark tables between PI and NPI are "close enough" for it to run, but they're still not ideal for the long-term. Getting the tune adjusted should be on the short list since it's been about a year since the swap, from what it looks like.

Have you checked the area around cylinder #4 for any signs of coolant? How old (and of what brand are) the plug wires? #4 may be intermittently opening up causing a weak or intermittent no-spark condition.

The plug wires are NAPA brand and I dont think Ive seen coolant. Ill check when i get a minute. Where can I get a tune and what would I ask for?

 

[theterminator93]

Don LaSota or David Dalke are the go-to mail-order tune guys familiar with MN12s. To do it right you will need an XCal2/3/4 flash device (unlocked if you get it used) and then Don or David can write and e-mail you the tune. You upload the tune to the XCal from a computer, then plug it into the car to flash it to the PCM. They will most likely ask you to record some data for them so they can observe the fuel trims to make minor corrections in the tune and dial it in.

Don runs his own website - lasotaracing.com. David I think has a presence on FaceBook as SuperCoupes Unlimited.

You will need to get the car running 100% before you try getting a tune for it though.

 

[mysterymau0521]

Don LaSota or David Dalke are the go-to mail-order tune guys familiar with MN12s. To do it right you will need an XCal2/3/4 flash device (unlocked if you get it used) and then Don or David can write and e-mail you the tune. You upload the tune to the XCal from a computer, then plug it into the car to flash it to the PCM. They will most likely ask you to record some data for them so they can observe the fuel trims to make minor corrections in the tune and dial it in.

Don runs his own website - lasotaracing.com. David I think has a presence on FaceBook as SuperCoupes Unlimited.

You will need to get the car running 100% before you try getting a tune for it though.

Thank you! do you have a recommendation for what mustang parts i should swap onto the t-bird?

 

[mysterymau0521]

OK, that makes sense because it would probably not have wanted to run with the Mustang MAF on the T-bird tune.

The spark tables between PI and NPI are "close enough" for it to run, but they're still not ideal for the long-term. Getting the tune adjusted should be on the short list since it's been about a year since the swap, from what it looks like.

Have you checked the area around cylinder #4 for any signs of coolant? How old (and of what brand) are the plug wires? #4 may be intermittently opening up causing a weak or intermittent no-spark condition.

I do not see any coolant around cylinder 4. Can you tell if I have an NPI or PI intake from these photos or should i get better pics

 

[LukesCougar]

Looks to be a doorman pi intake. Not 100% sure though. Those are npi valvecovers though

 

[mysterymau0521]

Looks to be a doorman pi intake. Not 100% sure though. Those are npi valvecovers though

That was the intake that was on the bird. do the valve covers make a difference?

 

[XR7-4.6]

I really can’t tell what intake that is with that big alternator bracket in the way(where did that come from btw(it’s not from a Tbird or a Mustang???)

The 01 Mustang 4.6 with the sole exception of the rare Bullitt with a totally different aluminum intake had the oil fill on the passenger side, so I assumed you swapped the ones from the Tbird on when you installed the engine. If those valve covers were on the engine to begin with it’s probably not a 2001 engine but rather a 96-98 npi

 

[theterminator93]

Since you swapped over the intake, do you recall if the intake ports on the heads were round or rectangular?