davmer24

Ok ive read through many of the forums that i can find on this issue and nothing figured out grrr lol. So here goes car ran great no issues at all was needing new egr and i was looking at it because the guy id bought the car from said replacing it wouldn't do any good and would just be $ wasted couldnt figure out why that would be so i checked it out to make sure everything was there pulled a wire off the sensor and looked reconnected. Drove the car for a day and then it started idling wierd surging up and down trying to die. So figured by unplugging i reminded computer egr was bad not sure. Anyway replaced egr, maf, car has new plugs wires just done a few wks ago on the car when bought was msd ignition, distributor, wires supposedly fairly recently as well dont look to old really. Id fixed some wiring issues the car had when i bought it like block ground being disconnected for one, new fuel filter. Im at a loss here i know how to fix things but this issues is driving me insane ive searched and searched for help in getting this resolved but nothing. Sometimes it will run fine for a little bit then start acting up when i get above 2600 rpm it seems to get better. I fixed idling issues and idles fine i can rev the engine and nothing no miss backfire nothing it only happens when i drive and the cars under loads. Any help would greatly be appreciated and if someone has a magic cure id love to know lol. Looking for as much help as possible as i really dont have $ to just throw at this car for unnecessary parts and ive went through everything i can think of to check. Thx ahead of time.

dawson1112

Make sure all the plug wires are secure on the plugs or that none of them has laid against the header or gotten burned. At night open the hood and look for arcing from the plugs and wires.

Run koeo/koer to check for codes, also perform the cylinder balance test.
Instructions below.
http://sbftech.com/index.php/topic,2471.0.html

post back with your findings or codes you got.

davmer24

Went through the plug wire check also check fuel pressure all readings on fuel were normal went ahead and changed plugs again even though just changed them a month ago. No arching whatsoever. I dont have o2 sensors or cats anymore. Really dont get any codes except one for fan speed and ac code 564 which i am assuming is because of the ac delete not sure tho. I keep hearing tps but havnt changed that yet mostly because dont really want to change parts unnecessarily. Really cant get to many techs none too close and with it running ruff dont want to.chance it to far i know its gotta be running rich exhaust is bad smelling but also ive gone through over 1/2 tank of gas just goin around town a few times maybe 7 so its burning it up quickly i know quitr a bit alexcept when something puzzling arises. Appreciate your response have any other ideas greatly appreciated thx

davmer24

Just got to throw this update in because it through me off never had this issue before but decided ti go down road again and came home car started spewing antifreeze out the overflow. That is completely new as car has never overheated since ive had it anyway. Heat sensor cause all these issues possibly

dawson1112

Wait , you don't have any 02 sensors? You have to have 02 sensors or the car will never run correctly.

davmer24

I may be wrong it might have them but i swore when i bought it he told me it didnt i may be wrong i was once but cant remember when lmfao. Exhaust is bbk headers off rd h pipe cat delete flowmasters dumped at axle will double check on o2 i just spoke with the guy i bought it from and explained to him this all started after last time i filled up figured since he had car forever done the rebuild and all maybe some insight from him ge thinks it may be the gas when i bought it he told me.never run 87 always 91 or above and if i do run 87 make sure i put a good octane booster in it to bring it way up well last time outta habit of filling our other car i filled it with 87 and drove it home. He said last time he accidentally did that filled it with 87 same reason used to filling his wifes it started acting up and he immediately got the booster in it and it straightened up but id already ran it a day and a half with the 87 with going to work and what not so im going to try the fuel drain and refill to see if it helps the overheating im guessing cuz fan relay went out again he told me to wire ran to switch because hes not sure but this would.be the 3rd its burnt out and just as a fail safe to have a backup do u think these ideas sound plausible i am inclined to believe him on some of these problems as i know he knows more about the car than i do. Do you think with it being cammed and built a lil that the premium issue is possible given the car has ran amazing up until my mishap again appreciate all your thoughta on this situation

88 orangepeel notch

Proper spelling and punctuation go along way for those that want to help but can't follow your description. Those are some pretty long sentences.

Verify that you do have the O2's hooked up like dawson said, but if you didn't throw a code for it, they should be there and working.

You can try the higher octane gas, but if the previous owner had it tuned that close to the edge that you can't run 87 octane, that's the first thing I'd change before you cause permanent damage. Have you heard pinging/detonation while driving it ?

dawson1112

I agree orange , pinging detonation would likely be very pronounced if it was an octane issue. And a very bad situation especially on those particular years 94/95.

And yes surely the computer would set a code for the 02s if they were not there.
And most likely the thing would run pig rich with out them.

List some of the stuff that is done to the engine, such as heads, cam info, intake, and Injector size. What is your fuel pressure reading? It should be between 34-36psi I believe. Where is your base timing set too? Also need to know if it has a chip in it that has been tuned.

As far as the fan is concerned it really wouldn't be that much of an issue overheating unless your in a lot of stop and go traffic, but cruising down the freeway the fan wouldn't come on anyways. It may be overheating if the timing is advanced to much. I would not run the fan with a toggle switch alone, youll need a relay to draw from the battery so you don't melt the toggle switch and wire going to it.

davmer24

Ok so changed gas issues remain. Thinking about changing msd distributor cap and rotor as it is a year plus old. Have came across a post in another mustang forum, guys issues ended up being a bad o-ring on the injector, going to pull, check, and clean. Would bad intake gasket cause these issues? Thx for all help to this point guys much appreciated.

dawson1112

Well a bad intake gasket, or bad injector oring will cause a massive vacuum leak and that will certainly cause issues.