Heres a tough one

[JoshGT87]

I have a 87 Mustang GT. Heres the problem. In the mornings right at the point it starts to warm up, it starts to miss. Sometimes it sounds like individual cylinders are cutting out and sometimes it sounds like for half a second all 8 cut out. After it warms up if Im cruising down the road and let off, its like the car just falls on its face. Then it hesitates to go. If im sitting at an idle and try to accelerate it hesitates. If it starts missing and a rev it up sometimes I get what sounds like an intake backfire. Here is what Ive done, new plugs and wires, cap and rotor. And I just bought a new TFI module, but I havent put it on yet. I tried to check for an upper intake gastket leak buy spraying TB cleaner on it. Any help would be great, thanks.

Josh

 

[custom89stang]

car burn oil? check the spark plugs?

 

[JoshGT87]

car burn oil? check the spark plugs?

Doesnt burn any, leaks a little. The plugs are as new as the wires, wich are mabey a couple months old. Looked at a plug anyways but it looked good and clean.

 

[Michael Yount]

Have you pulled the diagnostic codes? The computer stores error codes so you don't have to just start changing parts by guessing at things. At the point of warm up, the car usually goes into what's called closed loop operation taking data from the O2 sensors and using it to help operate more efficiently. Sounds to me like you could O2 issues, or intake air or coolant temperature sensor issues. If those systems are causing problems, it should be indentified in the error codes. You can buy a scanner at WalMart for about $23; go to AutoZone or PepBoys and they'll usually pull them for your for free. The diagnostic port comes off the wirng harness behind the driver's side strut tower.

 

[SynMan5.0]

Josh,
Did the miss happen right after you installed the plugs, wires, cap and rotor, or has it always been there?

 

[JoshGT87]

Josh,
Did the miss happen right after you installed the plugs, wires, cap and rotor, or has it always been there?

Cant really remember when it started, its been there for quite awhile, it just seems to be getting worse.

On another note: I see you have a Lentech AOD. I ordered one awhile back and it just came in. Ill be putting it in this weekend. Hows yours workin out for you?
Thanks,

Josh

 

[sunburstpony]

josh sounds like you have a timing problem. get the timing checked out and also check the plug gaps. when timing is off you will get a backfire and hesitation. the backfire sounds like a clicking noise in your intake. has your engine been built. worn timing parts can jump timing.

 

[CobraWannabe]

I was also going to say check the timing.

Michael, do you mean I can get a scanner to pull codes for $23???? I thought they were like hundreds?

 

[SynMan5.0]

On another note: I see you have a Lentech AOD. I ordered one awhile back and it just came in. Ill be putting it in this weekend. Hows yours workin out for you?
Thanks,

Josh

Awesome . The transbrake stopped working at one point, but they sent me a whole new valve body and solenoid and everything under warranty. Also, if the tranny gets hot enough it won't shift into overdrive. Other than that I don't really have any complaints. Last time we dynoed the car it was making 534 rwhp at about 11 psi of boost and the tranny has held up great. Did you get the full manual valve body?

 

[Michael Yount]

Scanners come in all makes and sizes, levels of complexity, etc. I bought one that works just fine for $23 at WalMart. You have to look up the codes in another resource, but I have Probst' book, so no problem there. There's a guy on the boards, JRichker I think (really sharp diagnostics guy) -- if you search here or the other site, and hit the link in his sig there are instructions for downloading the codes MacGyver-like - using a paper clip and a banana peel or something. Seriously, you can download them using a test light if you know what you're doing. See his site for the really cheap version.

 

[JoshGT87]

No I just got the street terminator plus, no transbrake or manual valvebody. Its goin in this weekend Ill tell you how it works out.

Let me ask you a question, how often do you use your OD? I have a pretty stock motor with 3.73 and on my way to work I have some pretty long stretches of 55MPH roads. Id turn it on and off probably a total of three times in 12 miles or so. Is that too much? I emailed Lentech and they said it was for cruising only, what do they consider cruising? 5 miles of 55Mph...OD would be nice.

Thanks, Josh

 

[89tang]

Maybe the TFI module is going bad? i agree with micheal it has something to do with your timing most likely. Might even check the coil too but i don't think it would cause all that trouble it might though i never had one get real bad. Could be O2 sensor also i know mine done that exact same thing yours did when my o2's went south. Get a code scanner an check that's your best bet

 

[JoshGT87]

O2 sensor wont make it miss.

 

[89tang]

You don't think, explain why mine done it then? To much fuel being dumped into the motor putting out the spark possibly? That would cause a miss

 

[JoshGT87]

Ford has what I think is called FMEM, I think its Failure Mode Effects Management. When a sensor goes bad the computer takes the last known good reading and runs off of it. I know thats how it works but Im not sure of the name. And plus my plugs looked good.