help! 5.0 transplant gone bad April 13, 2005, 08:39:27 PM hi folks , i have an 88 t-bird sport that i swapped in the HO with the 5 speed and 8.8 posi out of an 88 mustang . i changed all engine related sensors and the computer, it runs smooth and has all kinds of berries :D however the idle is around 1200-1500 rpms and it runs very rich - this aint no skeeter killer when this thing runs crows fall out of the sky and smoking would be fatal ! i have replaced almost every sensor under the hood with no results . it did seem to run a little on the rich side in the mustang but i dont remember this much smoke or the eye burning stench of raw fuel at the tailpipes or the gas in the oil , it doesnt seem to be burning oil just getting more gas than it can actually burn , im out of ideas and about ready to throw a match at this thing :flame: any ideas would be greatly appreciated Quote Selected
Re: help! 5.0 transplant gone bad Reply #1 – April 13, 2005, 08:45:40 PM Is it mass air?Map sensor unplugged?TPS?O2 sensor? Any vacuum unplugged?Im out of idea.... Quote Selected
Re: help! 5.0 transplant gone bad Reply #2 – April 13, 2005, 11:29:09 PM I have to ask:1) Did you use the Mustang HO computer when you did the swap? 2) Which wiring harness did you use? If the t-bird harness did you re-pin it for different firing order?3) Are your o2 sensors plugged in to their respective wiring harnesses? The wiring on one of mine broke once and then I couldn't stand within 10 feet of the car without my eyes tearing up...4) If all this is good..What is your car's idle RPM in Park and then drive? Quote Selected
Re: help! 5.0 transplant gone bad Reply #3 – April 14, 2005, 12:30:29 AM sounds like how my motor ran with 19lb injectors and the stock EEC, my money says the stock computer thats setup for 14lb injectors is still in the car Quote Selected
Re: help! 5.0 transplant gone bad Reply #4 – April 14, 2005, 12:48:02 AM Guys you ain't readin what's posted, he said he swapped the the computer.. BTW the Bird harness does NOT have to be repinned for the HO firing order, that is automatically taken care of by the EEC.Assuming its a speed densety system, sounds like the problem is either a bad MAP(or no/low vacspooge to it), or a leaking fuel pressure regulator. Does it have any error codes?Does the engine have a performance cam installed?? If so low vacspooge signal to the MAP will cause rich idling. Quote Selected
Re: help! 5.0 transplant gone bad Reply #5 – April 14, 2005, 07:22:16 PM QuoteGuys you ain't readin what's posted, he said he swapped the the computer.. LOL missed that my bad Tomas :rollin: Quote Selected
Re: help! 5.0 transplant gone bad Reply #6 – April 14, 2005, 10:03:28 PM yes it does have the mustang computer,yes it is speed density, tried 3 different map sensors good vacspooge at the sensor, no vacspooge leaks-chased all hoses and gaskets with throttle body cleaner, no engine codes, tried 3 different pressure regulators 2 that i knew worked in simmilar cars, new tps, new 02 sensors tried switching the plug ins no change at all, tried adding ground cables- engine to chassis- no difference . when i got the donor mustang i was told it was bored 30 over , it is very possible the guy put a different cam in not knowing speed density wouldnt pick up on the change. last summer after i finished the swap i had it towed to work (local garage with good fringe bennies) and custom bent the exhaust while it was there we - my self and 2 of the other techs looked over everything to no avail and the assistant managers genissis scan tool was down so no help from broken expensive oversized gameboy! think the computer is brain dead? maybe a good excuse to convert to mass air? thanks for the ideas, keep them coming please ! Quote Selected
Re: help! 5.0 transplant gone bad Reply #7 – April 14, 2005, 10:14:10 PM It would be a good idea to check the amount of vacspooge the engine is producing.... If it doesn't have at least 16"-17" you're gonna have problems. My Trick Flow cam only produces 12" at 800 rpms, so Mass Air was mandatory for me...Sounds like you've about covered it all, possibly the EEC may be bad. Doesn't happen often but I've seen or heard of half dozen or so with various quirky problems. Two were 5.0 EECs that would flood the engine on a hot restart. Quote Selected
Re: help! 5.0 transplant gone bad Reply #8 – April 15, 2005, 12:12:30 AM Hey welcome to the board cobra88bird... If you convert it to Mass air you can pick up the harness from IST.. for ~$35 IST's website Quote Selected
Re: help! 5.0 transplant gone bad Reply #9 – April 15, 2005, 01:07:34 PM also, i second checking the fuel pressure regulator Quote Selected
Re: help! 5.0 transplant gone bad Reply #10 – April 15, 2005, 05:58:50 PM it seems like i can remember checking the vacspooge at one point and i want to say it was around 14" but ill check it again when i have a chance , i already have a maf sensor and the wiring harness along with a very ported intake setup ( not on the car yet) that i picked up from a local ford fanatic (65$ for everytihng)all i need is the computer to do the swap but he highly encouraged me to get a set of world products heads , f303 cam , and several other goodies and do everything at once, he said he ran a simmilar setup in a crown vic and there werent many cars around here that would touch it at the strip - 1/8 mile . i have been looking around the site and you guys have some real nice looking cars ! mine aint that sharp, i live in the great state of maine and road salt has taken its toll on the poor car , but i found a good a good set of doors , and fenders after a year of searching hopefully by fall it will at least be all the same color and if i can figure this computer out ill post a pic! thanks for the info. any suggestions on future mods are welcome i would like this to be a streetable car that will hold its own at the track , i have yet to drive it anywhere yet(legaly) as this is a toy and funds are limited right now. Quote Selected
Re: help! 5.0 transplant gone bad Reply #11 – April 16, 2005, 05:26:27 AM I'd stay away from that F cam if your going to be running it on the street. It has more duration than my Stage-1 Trick Flow and its all I'd want in a 5.0. I have to fight surging idle in cool weather(under 55*-60*)on cold starts, and the F will prob be even worse...If it only has 14" of vac sounds like there is already a E or something similar installed.. Which ain't a bad cam for a street occasional strip car. Quote Selected
Re: help! 5.0 transplant gone bad Reply #12 – May 01, 2005, 07:09:55 PM I did the same swap with no problems. The computer should have a "D1" sticker on it. I was told you cannot use the computer from an AOD HO, only the 5 spd computer will work. Check the size and condition of the injectors. I replaced mine with reconditioned ones (19#) and they work fine. See the tech section in coolcats for info on your swap and EEC info. As mentioned above, the mustang computer will take care of the new firing order. Good luck. Quote Selected
Re: help! 5.0 transplant gone bad Reply #13 – May 01, 2005, 07:21:00 PM BAH its a old wives tale... prior to '94 either stick or auto EEcs work just fine for one another. Quote Selected
Re: help! 5.0 transplant gone bad Reply #14 – May 16, 2005, 08:54:08 PM I HAVE A 88 too. My car does the exact same thing yours is doing.I also did the swap but i used a 86 gt motor with low miles. I used the 86 mustang motor harness and 02 sensor wire harness and plugged them into the Tbird's main wiring harness. My car does the same thing you're saying. The one thing my car is doing that you didn't mention is my fuel pump continues to run all the time .example when you turn the key to the run, not crank , the pump comes on and pressurizes the fuel system, well mine just runs, and runs. it does cut off when the key is turned off though. LET ME KNOW HOW YOURS TURNS OUT .......GOOD LUCK.......ED Quote Selected
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