My father just bought a '95 gts w/ several engine mods and this thing is all over the map. Mods are as follows: cold air intake w/K&N filter, Trick Flow upper & lower intakes w/ 65mm throttle body(unsure of which package it is), AFR alum. 165cc heads,1.6 roller rockers, b303 cam,offroad x-pipe(2.5" front to back), 24lb. injectors. Stock eec as far as I know. This engine will idle sometimes and sometimes it won't fall below 2500rpm. Shifting under normal conditions, it will never drop rpm between gears. Take off is almost impossible w/out getting in the throttle. This engine just doesn't feel like it has the power it should. All of the stuff above is on a new stock shortblock w/ a few thousand miles on it. We took it to Mustangs of Dallas to let them try to tune it in. They replaced the MAF sensor and bumped the fuel pressure up to 41psi. It simply isn't any better; they want to replace the eec but my dad decided to stop there before he threw more money away. My '88 lx had been converted to a carb setup when I bought it. I left it alone and spent money elsewhere on the car. Soooo, I'm not sure how and if all this will work w/ the stock eec. Anybody got an idea of the next logical step we should take?
If you are in Dallas area , call Dallas Mustang 1-800MUSTANG , ask to speak directly to Mike Wilson , he is their tuner , they are a dealer for SCT , Sniper and maybe Diablo as well , I am confident that he can get you a chip in the car that will make it run like stock ....
Thanks for the info. I think we are talking about the same place. It's on Sandhill right off of LBJ Freeway.I know they're a reputable shop. I don't know who worked on the car. They wanted to put a complete aftermarket eec in it & then tune it in. If they wanted to piggyback a chip in, my dad didn't tell me. The $ for the new eec & tune was more than he wanted to spend not knowing for sure if it would line out the car. If you think a chip is all he needs, I'll have him contact Mike. I know this problem can't be that unique and somebody should know how to get around it. This pony has enough hard parts on it to be a strong runner & I'm anxious to see what it will really do.
A chip will certainly help, but you could have several other basic things going on. Work on maintenance first before you try to have it tuned. Otherwise, you'll have to have the car re-tuned after the maintenance is done. When was the last time you cleaned the K&N filter? They need to be cleaned now & then, there's a specific K&N cleaner kit sold at auto parts stores. Even though the MAF was replaced, it might still be dirty. Search these forums on "clean MAF" and you'll find out how to take apart the MAF and clean it. Has the fuel filter been changed? If it's clogged you'll definitely have problems. When was the distributor cap & rotor last changed? How about the spark plugs & wires? Check for broken, cracked or unhooked hoses in the engine bay - a vacuum leak can cause a lot of problems. The surging idle is pretty common after changing the engine as much as your Dad's GTS is - the B303 cam can give the 94-95 computers a hard time. Or you could just have a sticky idle. Look for the Idle Air Controller (IAC), and spray the inside of it out with throttle body cleaner. If your idle changes afterward, the IAC is bad and needs to be replaced. Regarding the chip, the 94-95 computer is more sensitive to engine changes than the 87-93 computer. Sometimes the engine will adapt to changes, sometimes not. It's a lot of stuff to check, but it's all good things to run through when you get a new Stang. If the previous owner didn't keep up on maintenance, the engine will run like crap. Keep up on maintenance, and your Stang will purr and be lots of fun.
Air filter and spark plugs are new. Fuel filter and plug wires are not but will be before anything else gets replaced.Dist. cap and rotor are also new. I looked under the hood as well as possible for a vacuum leak before the car was purchased but didn't see anything obvious. It is possible though; didn't have much time snoop around that day. I've heard from more than one that the 94-95's can have a mind of their own. Maybe it's true. Thanks for the tip on the IAC. I've been wondering if it could be a contributor to the problem, but I honestly don't know much about their function. I'll do a little more research & go from there.
I wonder, did you check the timing? Have you tried to change the timing? I made a bone-headed mistake on my GT and had the timing set to 10* ATDC (after top dead center), rather then BTDC (before). I had a new harmonic balancer on that didn't have BTDC and ATDC on it, and I guessed wrong. Oops. The engine ran like a dog as well. If you're not sure, rotate the engine by hand until you find TDC (0). BTDC is on the right, ATDC is on the left. there will be more numbers on the BTDC side. ATDC usually only goes up to 10. Even if the timing is set to 10*, it might be worth changing the timing and see how the engine reacts.
Told my dad yesterday to finish up the basic stuff any new-used car should have done to it and gave him Mike's #. Dallas mustang is the same place I mentioned in the 1st post; juuust didn't quite get it right. You also have to understand my dad is an old school hot-rodder(66 in may) and although this is his second FI mustang, it's the first one w/ problems. In his mind you shouldn't let somebody else diagnose & repair your car! His first reaction after the thing came home from Dallas Mustang was to gut the FI setup and go carb like somebody did mine. I talked him down off the ledge and now he's truly interested in figuring out the FI system & what makes it tick. If he does all he should and understands why he's doing it and the car still needs a chip and tune, that's ok. He'll feel like he's done his part and a trip back to Dallas Mustang would make both he and the car happy.
Timing was an issue. When he checked it initially, it was at 18-20btdc. To much advance as far as I'm concerned. We verified that when the pointer is on 0 deg the piston truly is @ tdc. We reset the timing to 12deg btdc. He also tried to maunually reset the idle speed and got it some better, but it still hangs between gears. I told him to clean the IAC valve,tb,& MAF. I also gave him instructions I found on this forum on properly resetting the idle manually. I told him if things weren't right after that, call Dallas Mustang back or maybe consider the IAC restrictor plate.
If your dad is still having idle issues, here's a couple of threads that may help. http://forums.stangnet.com/681528-new-tps-fixed-my-hanging-idle.html http://forums.stangnet.com/680767-surging-idle-what-worked-me.html Keep us informed, I'd like to know what fixes the problems.
