found out i have wrong engine!!!

Discussion in 'Fox 5.0 Mustang Tech' started by odsysean, Nov 29, 2012.

  1. There are some concerns you need ot keep in mind before grabbing engine harnesses. First off, in 1990, the harness interface between the body harness and engine harness changed. So that means any 1990+ engine harness won't work for you.

    I beleive 86-88 Speed density harness is the same. I do not know 100% however, so you might want to do a little research here. I'd do it for you, but it took me 4 days just to reply here. 1989 Mass air harness will work too, but it's expensive. Guys want top dollar for these, when a stand along MAF harness is $40. If you plan on running the stock camshaft, you really don't need MAF, but if at some point down the road you want to do the swap, grab a meter, an A9L and the $40 stand-alone harness and it's an easy job.

    My opinion, take care of this harness issue first. Swap in an OEM stock speed density harness and get the car running great. The computer will generate codes for faulty sensors and such. EFI is pretty easy to deal with and troubleshoot.

    I know you want to do mods to the engine (heads and such), but i would put that on the backburner for now and ger the car running great. Otherwise you'll jus tfrustrate yourself in the long run by doing too much at once. Trust me...i speak from experience. Just tackle one issue at a time
  2. I did the DIY Maf swap and made my harness... Not hard at all..there are instructions on here somewhere.. Swap a couple pins on the computer.. Done..couple hour job
  3. a carb/intake/cleaner assy. runs about 480.... 600 with vac secondaries. Right now, the mustang has bad wiring problems (runs extremely rich, poor idle, bad hesitation, hard starting, misfire/backfire, etc). the wiring harness isnt in good shape (bad connectors, old cracked wires, stiff) and currently i attend automotive school so I brought my heads in to get the valves seated properly and it will cost $15 to do a 3 angle valve job on all 16 valves. Valves, guides, push rods and lifters are in good shape. once i get the heads back on im just contemplating efi or carb. i know more about carb as i took hi-perf class, but these early obd systems are rather simple. my old injectors were in horrible condition so i replaced them with bostech remanufactured units that costed about $40 a piece. I also bought a new tps, act, ect, iac and map sensor due to age and wear. Also, The cap and rotor are relatively new (about a year old) with maybe 30 miles on them, the plug wires are about the same age and usage, and i went through too many plugs due to gas fouling. The ign. coil is also newer but is a autozone part (crap). The battery/starter cables and starter are also new. somewhere along the lines, there is either a wiring issue i cant find, or the pcm has gone bad, because it ran like absolute crap. there was so much carbon and i got maybe gallons to the mile (sarcasm). the oil kept getting gas fouled. it gets spark, has compression and obviously gets fuel. I ran out of ideas which is why i was thinking about a carb swap. Im a die hard fox body fan and finally got the 4 eyed i always wanted. the only rust is surface rust on the rockers, but everything is different colors, and it needs a new top. Im only focused on getting it running right now. Anytime I tried to really get on it, it would miss and bog really bad, barely crawling the car from a stop. There is no acceleration nor response from the engine whatsoever. it would blow black/white smoke like crazy although it has no cats, shouldnt spit gas like it does. I think the problem is most definitely a fuel problem, its dumping too much fuel. After the sensors were replaced, it still ran horribly and i even drain the computer of its power to relearn itself but it still runs the same. is it a bad computer? I have no idea at all
  4. Have you done a rebuild lately? You said you rebuilt the heads, did it act like that prior to doing the valve job? It's possible the heads weren't torqued correctly and compressed one side of the gasket more than the other. It could also be a piston ring issue. White smoke is usually oil burning. It has compression but is it maintaining or bleeding off? When you did the heads did you replace the valve seals? If you have the engine out of the car I'd pull the cam and check the lobes. A local machine shop could polish the cam for around $20. These are all just ideas.

    Sent from my SGS2-SR with Tapatalk
  5. "White" smoke is water/coolant.
  6. I disagree. I have an 88 that blows white smoke, never loses coolant, no leaks anywhere, burns a quart of oil every 3 weeks.

    Sent from my SGS2-SR with Tapatalk
  7. Check to make sure your fuel pressure regulator isn't bad. If it's bad, it'll dump so much fuel that it'll get into your oil.
  8. im in the process of rebuilding the motor... head gaskets were bad along with intake gaskets. you can resuse guide seals onces they are removed, so yes i got new seals. i got a 3 angle valve job for about 16 dollars at my school, they did a great job too. cylinder leak test showed to be good, but since its all apart im putting new pistons an rings in. it did blow a bluish white smoke, and my fuel pressure regulator is brand new, pulled the vacuum line off while running and doesnt spew fuel so i assume its functioning properly
  9. After all that trouble, did you ever check for codes?

    Okay, then what is causing the "smoke?" White is water, blue is oil, and black is fuel.

    And turn off your damn phone's Tapatalk signature.
    88LX5.Oh likes this.
  10. All I'm saying is my car loses no coolant anywhere. The exhaust doesn't smell sweet which is an indication of burning coolant. My car does however lose about a quart of oil every 3 or so weeks, the plugs on about 4 cylinders are always oil fouled, and there's oil in my tail pipe. When I cold start it and when I get on it I leave quite a cloud of white smoke behind me.

    I deleted the auto sig just for you. Feel special ;)
  11. lol the pcm wont communicate with anything. no test light/paper clip worked either. led to wiring issue or just a :poo:ty computer. and it smokes all bad colors lol black blue and white
  12. I started building a 306 for it because mine is doing all of the same things. I got as far as machining an E6 block 030 over, polishing the stock crank, checking and machining the stock rods, installing new bearings and freeze plugs, blah blah blah then ditched the idea in favor of a 32 valve modular swap. So now I have a 306 short block on a stand and no plans for it.

    Not sure where I was going with that, bored I guess :D
  13. What you're seeing in the rear view is grey smoke. It's light grey, almost a white. That is the oil that you're replacing every 3 weeks. Time for a rebuild from the bottom up.
  14. Thank you for confirming my earlier posts. And believe it or not the engine was rebuilt just before I bought the car. I even have the receipt to prove it. Talk about a crap rebuild.
  15. if you dont need a choke i would put an AED 750 HO or HO modified on it. if you need a choke look at quick fuel.
  16. Sounds like someone got some sh*tty piston rings.
  17. No joke. And it ticks like crazy. Just looked at the receipt and there's just under 4k miles since the build.
  18. I'm sorry, man! That's really terrible. 4k miles and that thing should just be broken in, not already smoking and ticking.
  19. That's just the beginning. I won't go into all the details but it's bad. Hence the mod swap