Brad6080

Just recentl got a 95 mustang gt and I'm having some issues. When I got the car it had been sitting in a storage unit for about 8 months. It aready had a explorer gt40 intake, bbk cold air intake, 75mm bbk throttle body, msd plug wires cap and coil, cats deleted, and no smog pump. Got it to crank but barely ran good enough to get it on the trailer. Got it home and found several problems. There was no distributor hold down on it at all, the main vacuum line from the intake was just gone, and the #6 and 7 spark plug wires were swapped up. Got these problems fixed and found the fuel pressure was at 28lbs at idle and dropped to less than 10 when revved. So, I got a walbro 255, new filter, new plugs, new cap, and cleaned the mass air sensor. Now it cranked alot better and the pressure sits where its supposed to, but after just cranking it a few times and not even driving it its missing again and the idle will fluctuate up and down till it just dies. Exhaust smells like raw gas but only on the drivers side, true duals. Tried to run a koer test and balance test but after a few seconds into the balance test car just dies. Every time it dies I have to hold the pedal to the floor to get it to crank back up so its messing up the tests. Checked the vacuum and its at 15lbs at idle. Only codes I get out of it have to do with the smog system.
Any suggestions as to where I need to go next? I'm bumfuzzled at this point

dawson1112

Im going to assume that you reset the timing when you put a distributor hold down on it?

Barring any vacuum leaks, and no 02 sensor codes,, Id say that sitting for 8 months in storage one or 2 of the injectors are a little sticky and leaking fuel. Do you get a big puff of black smoke out of the exhaust when you start it up?

Holding the gas pedal to the floor during start up the computer shuts off the injectors until it starts. This tells me that it is flooding out.

Initially when starting up the car,, the ECM looks at several sensors to adjust timing and fuel. The most important start up sensors are the MAF , IAT, and ECT. The IAT is the intake air temp sensor,, and the ECT is the engine coolant temp sensor.
The ECT is a vital sensor for start up as it tells the computer what tempreture the engine is at.. I have seen them go bad quite often and give a false reading of -40 degrees F. If this happens the computer just pours fuel into the cylinder because it things its freezing cold out. Think of this sensor being bad as a stuck closed choke on a carbureted engine. The ect is located on the passager side of the intake, up front just behind the thermostat. Unplug it and see what it does,, this should cause the fans to run on high speed, unplugging that sensor is the same as telling the computer the car is hot.

Brad6080

Ok just unplugged the temp sensor and the fans did come on high speed. Also tried unplugging the maf and the car just died when i unplugged it. Ran the codes on it koer and got a 314, 311, 536, and 632. Did a engine balance test and got 10 and 20 right before the car ran out of gas. Ha

dawson1112

None of those codes mean anything in relation to how the car runs just emissions codes and then the break switch and over drive switch common when you dont touch the break pedal or od button during koer. Codes 10 and 20 just mean it failed the balance test on those 2 cylinders, but that is to be expected if the car is missing.


Did the car run any different with the ect unplugged?

Brad6080

Other than the fan coming on no

Brad6080

One strange thing tho. Just before it ran out if gas the idle smoothed out, almost seemed to stop missing, and the surge went away

dawson1112

Well it was running out of gas so it probably leaned out just enough to idle correctly for a few seconds.l

Brad6080

Shouldnt it be throwing a code for running rich or lean?

imp

Ought to be, but one thing comes to mind. '94 had only one O2 sensor per side, '95 had 2, on either end of both cats. Not really pertinent to cold start-up, but just wondering: Are the cats intact?


Engine Coolant Temp. sensor can really throw things out of whack, as said. My problem was no "idle-up" (basically, "choke") on cold start-up.


Can't recall all the mods you mentioned, but is it possible the mods never worked, and storage was the result? How about bigger injectors installed without matching MAF?


Yes, hopefully you reset distributor close to normal location, and tightened it down, though screw-up there I don't see causing extremely rich operation. imp

Brad6080

Mine has no cats but only has 2 o2 sensors. Looked around under car and dont see any.wiring for more. Still has stock injectors but i have a set of the newer style 19lb injectors I'm considering installing to see if it makes any difference. Unplugging the temp sensor does cause the fan to come on, but i guess that doesn't mean its functioning correctly. It does seem to run much better when cold till it heats up