What would be causing this.***UPDATE***
 

Still trying to work out the bugs in my car.

I started it up again today after a week, and it idled great. i was on empty, so i figured i would take it for a short drive down to sunoco.

Temp was at about 130 when i started driving it.

I drove it down nice and easy. pulled into the station, and threw a half tank of 94 in it.

started it up and started driving back, and started running like complete crap again.
sounded like it was missing, and bogging.
i was easy on it the whole way.

It did this to me the last time i drove it. ran great until we were driving for a few minutes.

why would it do this after it got warmed up all the way and driving?

Sounds like a bad plug wire or coil? maybe a sticking injector? next time it happens, try unplugging injectors to isolate the offending cylinder, then pull the plug for inspection.

Nope has nothing to do with any of that! Warren you need a tune! Your computer is all fucked up!
Have you put new O2's in it yet?

Find someone with the same setup if not a little close and run there tune!
try your svtperformance site, or even try eectuning.org and ask the guys on there..... maybe they can help you!
Did you read the entire manual?
http://www.sctflash.com/forum/attach...0&d=1132504812

You have a fresh rebuilt engine, new injectors, new MAF new everything so it has to be the eec.
No tune no run.
That car must see Steeda or someone with a dyno.

I agree you DEF need a tune at this point.

Have you verified your not having fuel pump issues?

ok, i was kinda suspecting my one coil pack, BECAUSE the clip broke of when i removed it last year. i did have it soldered back on at an electronics place.

Fuel pump is throwing a code, but it is a brand new walbro 255LPH HP.

If it is the tune, why would it not run like crap ALL the time?

What do you mean the fuel pump throws a code,what are your codes....and does your car have a returnless fuel system??

Warren its the EEC....
You need a tune!

There are 3 different computer controlled substances that you have no control over...

-Open Loop
-Closed Loop
- and Limp Mode

See your car is running great at one point then all of a sudden it runs like that is because the EEC automatically goes into one of these 3 modes...

"OPEN LOOP" = Fuel control when the EEC is relying on tables to control the fuel injectors.

"CLOSED LOOP" = Fuel control when the EEC is using the oxygen sensors as feedback to control the fuel injectors.

"LIMP MODE" = This comes in when your MIL (Malfunction Indicator Light) {Also know as check engine light} comes on, so when one of your sensors bites the dust (O2's etc...) it goes into "LIMP MODE" which means it will tell the EEC to run like the last time it ran good.

"OL" = Open loop, not reading the O2 sensors
"CL" = Closed loop, reading the O2 sensors

"OL" vs. "CL" = Open loop, happens at first initial startup and lasts until 160* or 255 Seconds of warm up time witch ever is reached first. The Closed loop takes over unless the "load" on the engine is too great [or], a sensor malfunctions. Then it goes back to "OL".
Generally speaking you make better power/response in "OL", cause its that little bit richer at part throttle and lower loads, but you don't get as good gas mileage!

So those awesome engine codes your getting is BAD and the EEC is going all crazy and stuff.

I cant explain it anymore to you.
GET A DAMN TUNE lol.

Good luck Warren.

The Codes are:
P1232-Fuel Pump Speed Primary Circuit (Two speed fuel pump).
P0412-Secondary Air Injection System Switching Valve A Circuit Malfunction.
I deleted my air injection, and i guess the "tuner" did not make correction for that in the tune.
The new fuel pump i bought from http://walbrofuelpumps.com/ and ordered the one marked "Ford Mustang Cobra 96-97"

Now I'm not saying i do not need a tune, i just want to make sure that i don't go up there on the dyno, and then they say, well it is "this" that is bad, then, charge me so much for the part and $100.00 dollars an hour to change it.

I just want to make sure i have all bases covered before.

Were is Steeda..................?
He should be the one chiming in, HE IS A CUSTOM TUNER!

Warren, check the basics firts, I think it would be a waste of time to get a tune for an intermittant running problem, at least pull the plugs for inspection. Yes, I agree the car needs a tune to perform at it's best, but I highly doubt it would cause this problem.
Open loop and closed loop simply are ways to calibrate fuel delivery, they WOULD NOT cause a misfire. If an 02 sensor goes bad, the car will still run fine, it has plenty of other sensors to help it keep the car running as it should. This sounds to me like a spark or fuel delivery issue, if the injectors are new, I'd look for a faulty wire, coil or plug. An inspection of all 8 plugs is a great starting point.
Are you sure it's a misfire? A misfire will usually set a code pretty quickly and usually flashes the MIL light to let you know it's a serious problem.

The code 1232 is a fuel pump voltage monitor code,meaning the fpdm is seeing incorrect fuel pump voltage..the fpdm maybe shutting down due to being overheated from your fuel pump drawing excessive current.

, i dont want to drop my tank again, but it will give me an excuse to run a bigger pump.


the wires were bought last year, FRPP 9mm, i just changed all the plugs the other day. they were black.

like i said it might also be the one coil pack.

maybe i will go down to ford an see what the want for one. or would a crappy tire one work fine?

A ctc coil will work,I would recomend installing a fuel pressure guage and test drive it till it acts up to observe your fuel pressure...also clear the dtc's and recheck for dtc 1232 after the car acts up.

Warren give me a shout if ya need a hand!

Ok, so i found out a little more.

I bought a new coil for the one that i thought could be screwed up.

So i installed it and started it, and then i went working on jens car. after 15-20 minutes, i heard the fan kick in, and the RPM's drop, then they went up, then down. each time it got lower and lower, until it stalled.

it did this also before the new coil pack.

Did you post this question on svtperformance? If your gonna get any help it will be on that site! Or maybe the Correl or even eectuning.org.

Good luck man!

But is it still misfiring? This sounds like a separate issue to me. Does it start back up? Will it stay running if you throttle it?

OK, the misfiring and bogging are gone now, I THINK. i let it warm up for 5 minutes and went for a drive, came back. worked fine. went for another drive, and still fine.

but it does still try/die when the fan kicks on....the up and down idle thing.
Also has high idle when coming to a stop unless you snap the throttle.

Maybe IAC, or tune now?

could be a vaccum leak also! try cleaning the iac, and check for leaks, or you may just need to drive it for a bit for it to learn a table, mine ran like crap for about 500 km after i put it back together!

vacuum sits at -16 at idle.
IAC was cleaned when it was put back together. I'm going to take it off again and re clean it, and maybe lube it.

I don't like to drive it too much, seeing i still don't know what the A/F is at.

I'll come up next weekend with the wideband and we will see what its running at!

Are you going to show up this time??? lol

I don't think you are supposed to lube the IAC Valve!!!

if it doesn't rain! can't really check it in the rain

The hunting idle may be due to improper base throttle plate adjustment....the car would need to be driven for at least 1/2 hr for the fpdm to overheat and bog/miss fire (dtc 1232)...

ok, well we can count out that right now, it has never driven more that a half hour.

but i will try going for more than a half hour and check it out.

Thanks for the info.

What is the next step up in Fuel pumps from a 255LPH? i wanna stay intank.
Or what should the 255 be good till (HP)

255 is the biggest intank that I know of!

I'd say the idle issue is likely a IAC or T.P. problem, could also be as Nick said, the base idle not properly set. A vacuum leak could also cause this but it should set a code pretty quickly. As for the fuel pump, does the code return immediately? maybe it's just a bad pump and is shorting internally? I'd first confirm no wiring damage/routing problems and then get a new pump under warranty. If you wanna go for a drive you should be fine as long as you drive easy, a lean condition usually shows up in the top end, do you have a code reader or hand-held tuner?

[QUOTE=Ponyryd;83785]I was thinking IAC also, but now that you mention the T.P problem, i know that i have to snap the throttle to get it to come down after driving it. also push back the throttle when under hood to get it to come down more. but that does not explain why it would go up and down when the fan kicks on.
Vaccum sits at -16 at idle.
no it does not come back on right away. i would say 3-5 minutes before it returns.

The fuel pump voltage on returnless cars are controled by duty cycle (via fpdm) and if the pump is not compatible the pump will draw more current shuting the fpdm down..setting the 1232 dtc...its not the fuel pump size thats the problem.You need to fix this issue first...

ok thanks nick.
The reason i asked if 255 was the biggest is because pat from steeda said 255 limit is 450ish HP.....
so if it is the wrong pump, i was just consider going bigger.


Is there a way to tell if the pump is for a returnless style car?

it went into place nicely.

It would fluctuate when the fan kicks on because the idle is commanded up a bit when the fan comes on to keep the engine from stalling due to the extra load the fan is pulling, so if the T.P. or IAC is a problem, it won't work as required, causeing the issue you describe.


As for the fuel pump code, I'm not too familiar with running non-stock pumps in returnless fuel systems, so I'd listen to Nick on that one.

How many lines did you disconnect at the sending unit, 1, or 2? if 1 it's returnless, if 2, it's a return-style.

It IS a return style system, it is stock with an upgraded pump.(1996)

Don't take this the wrong way but reading your posts makes my decision easy,

Step 1: Get car running with base tune, make sure there are no leaks etc.
Step 2: Drop car off at Tuners
Step 3; Pick up car when it is running perfect or blown up.

LOL

Easier said then done.

i got three tunes off of steeda, +5% fuel tune was WAY is rich. base tune is way to rich, and -5% fuel is rich.

closest tuner would be dasilvas, and even at that they are over an hour away. the steeda @ 2 hours away. i have been talking with cobraNT though.thumb:

But that is what i am doing, making sure there is NO mechanical problems left so their job is easier.

Well thanks to Nick and Chris that let me borrow their wideband, we made a couple pulls down the 401.

Well after some pipes blowing off from the boost we finally managed to get 11.0 for A/F ratio!!

It is running alot better.

BUT we had to drop the fuel pressure down to 25PSI (VAC OFF) to get it to lean up.
We started off at 8.X A/F ratio.

So my tune is a WEEEEEEE bit rich!

It is idling a lot better, and does not want to die as much when the fan kicks on.

So we are figuring it is all in the tune now, and nothing mechanical!!!

good to hear it helped out! now you know its safe to drive, a little rich, but safe! So what do you guys think of the wideband? did you hook up the aux box and check boost?

No we did not messure the boost, we are going to do some more maybe today and figure how much boost it is creating.

I am going to be buying one very soon, the same one.... I love the layout, it seems to be user friendly etc...

Yes we hit 11.0 A/F under WOT @6500RPM
Idle/driving is around 10.0 A/F still much rich but the cars seems to be performing much better.

When we started the first drive with the W/B on it... the car was idleing and hitting 9.3 A/F when the Cobra got released in WOT mode in 3rd gear it went directly at 8.4 A/F running stock 39.5 Fuel PSI (Vac off) just horrible!!!!

Still feel sorry for the person behide us smack: ....lol

you going to get that from me? and how does the beast work! he should still take it up and get it tuned!