3-4k rpm miss/sputter WOT

[lib88stang]

I have an 88 5.0, it just started to sputter at 3-4k rpms at WOT,it feels like it doesn't want to pull past 4k rpms. At normal acceleration it doesn't do it, but if you punch it, it starts to sputter then take off but doesn't pull as strong as it always did.

I have changed the following: plugs after it started doing this, wires 1 year ago, tps sensor 1 year , coil 1 month ago, cap and rotor and new distributor 1 year ago, checked computer last year OK, checked MAP sensor last year OK,checked EGR OK, Put adj fuel pres reg last year, fuel filter last year, 190lph fuel pump last year, I have a fuel pres gauge and the pres when driving is 38-40psi and when it sputters it doesn't drop.

Any help is appreciated

Also car has been having a bad vibration at 4k rpms and higher I can't tell if its tranny or rearend, shifter shakes bad and I have a poly urathane mount. It hums but the gears have been in it for 4 years now they are 355 but it feels like it has 410 in it. I don't know whats wrong. Please Help.

 

[jrichker]

The TFI module on the side of the distributor is the prime suspect when everything else is new and in good condition. They tend to fail most when the engine is warm.

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/article...c-iv_codes.html

IF your car is an 88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart .

 

[lib88stang]

The TfI module is also 1 year old I also heard that they either go bad to the point where the car won't start or don't-no in between.

Please give me more info

 

[mac7290]

I'm having the same exact problem. It's fine when you roll into the throttle but at WOT it starts missing after 3 grand. If I reset the puter it goes away for 2-4 days then comes back. So everytime I think I fixed it, it pops back up. I've changed the feul filter, air filter, adjusted the TPS checked all connections, plugs, wires and so on. No fix found yet. No codes are popping up either. if you figure it out let me know and I will do the same, thanks. E-mail @ [email protected]

 

[lib88stang]

I haven't figured it out yet, but I am going to install a MSD 6al this week.

Do you think this may help??

I know someone out there had this problem and fixed it so PLEASE help

 

[modulistic]

maybe your fuel pressure is dropping off? fuel pump going bad? fuel filter clogged?

 

[lib88stang]

fuel filter is about a year old, fuel pump is 2 years old, I have a fuel pres gauge and it doesn't drop when the miss occurs.

 

[HISSIN50]

fuel filter is about a year old, fuel pump is 2 years old, I have a fuel pres gauge and it doesn't drop when the miss occurs.

then i would defer back to JR's great advice - TFI.
what brand is the one you have on there. remember, it is suscepted to high heat and is busy - it can fail (esp depending upon brand) in short order. if it does this at any temp, take it in for a bench test. if it happens only when the motor is hot, that is the prime time when they fail (when on last legs).

for you vibration issues, does it happen at 4K in any gear, or only higher gears (relating to absolute speed)? if former: check your balancer. if latter, check DS.
good luck.

 

[lib88stang]

So you mean the TFI can start to go bad and make the car do that?? I always thought they either worked or didn't.. The brand I put on my car is autozones brand.

I have an alum driveshaft but I guess it could have lost a weight.

How do I check the balancer???

 

[HISSIN50]

yes, TFI's can do that.

the alum DS is probably alright. like i said, if it vibes at idle while revving, that points to the balancer (there are other things, but it is no. 1 on the list).

take a look at it. is the elastomer cracked. does it wobble while idling? are the timing marks still accurate (or when you time it, are the timing marks off). stuff like that. the outer ring can slip on the inner ring (why you check the elastomer) - and that is not a good thing.
good luck.

 

[lib88stang]

I am going to take off the TFI and have it checked, also I will check the balencer, but it vibrates while driving at high rpm's ??

I guess the DS could have lost a weight because a buddy had that prob with his alum DS.

Would the MSD box help? also what is needed to hook it up??
all I have is the MSD 6AL box. Where do the wires go??

Any help is appriciated.

 

[modulistic]

lilb, im assuming you have just the box with a bunch of wires coming out. I was in the same boat. here goes.

inventory
thick black
thick red
thin black
thin red
orange
white

any other wires are not used

MSD 6AL.
you have a fat red wire and a fat white wire
fat red goes directly to the battery. apparently it MUST go directly to the battery to supply adequate power.

thick black goes to a good ground or ideally neg term on battery.

thin red wire is what turns the box on and off so it doesnt drain your battery down when the car is off. it goes to switched 12V. a great source is the red with green stripe wire that normally connects to your coil. splice it together with a wire nut or crimp connector

thin black wire goes to the negative side of the coil. it is the only wire that will go to the negative side of the coil. you can tell the negative side by pulling out the coil plug and looking down into the socket. there will be a neg and pos symbol. pretty important. on my car it was the side nearest the fender

orange wire goes to positive side of the coil. it is the only wire that will connect to the coil. if your coil is stock style, you will have to fabricate something to connect it properly or, like I did, connect it with alligator clips so I can unclip them and make my car unstartable easily.

white wire is the trigger signal wire for the MSD box. It is the wire that used to go to the neg side of the coil. that wire (on my car) is orange with a white stripe. I crimp connected these together


oh hey, next time your car starts missing, spray the TFI module with a mist of water from a spray bottle or something. apparently the cool water will cool it down enough if its bad to work properly again

 

[modulistic]

here is a bad ass little pdf that I found so you can see a picture of how it goes.

http://msdignition.com/pdf/6series.pdf

its on page 19, has a perfect little illustration.

if you get that harness part number 8874, it looks like it would be a snap to install, but some of us like to go the hard way.

 

[HISSIN50]

sorry, i mis typed earlier. i meant to say that if the motor had vibration issues while revving, but stationary, that suggested balancer.
if that checks out alright, but it vibes while moving (esp at higher speeds - not engine speeds, but absolute speeds), that indicated a driveline balance issue.
good luck.

 

[lib88stang]

Thanks you guys have been real helpful and I am going to check all of that.

The MSD plug adapter? If I get that what wires does that take care of??

 

[HISSIN50]

i think the wiring adapter allows you to truly plug and play - no cutting or soldering wires. makes it nice if you go back to stock.
good luck.

 

[MadMatt5oh]

Does it vibrate though the shifter handle alot? It could be from a seized stock clutch fan. Check that fan, thats one issue I have

 

[lib88stang]

It does vibrate through the shifter alot.

 

[lib88stang]

I had the TFI checked out today and it was fine

Hooked up the MSD and it works

Problem now is a slight miss at 2k rpms when the cars is pulling. The WOT miss is gone.

Any help is appricated?????