So there’s some issue with my SHO that I have spent the past year and a half on and off trying to solve…and it’s driving me nuts since I haven’t found the problem.
To sum it up I took a '93 SHO that was in perfect operating condition and swapped the automatic to a manual using a SHO parts car. Well since the swap the car has had an issue where it idles like crap and doesn’t feel like it’s all there powerwise. I’ve put on about 25,000 miles so it still runs and all, mpg is down a bit but it isn’t horrible, it’s just kindof annoying to have a car that it’s functioning properly.
I have checked and rechecked damn near everything that I can think of, as well as what several others have mentioned. Many parts have been replaced. Scanned codes and nothing comes up…I love OBD1.
So, given this situation, how would you go about trying to solve this??? I really have no intention to drop it off at a shop…I can only imagine how much that would cost. I could sell it as is…but SHO’s barley command any money as is. I’d be willing to have someone look at it ‘on the side’ and swing them some cash, but I don’t know who qualifies for this. All i want is the problem diagnosed, I can handle the rest.
PS, even though most of NYSpeed hates SHO’s, please be gentle…all I want is ideas on a possible direction to take to getting this thing fixed.
-call alex
-retreive gen1 mtx harness off my engine from his storage unit
-install
-give me your old damaged harness for when i install engie / megasquirt in my car
ill find the problem in the wiring when i hack it apart, lengthen the needed wires, and then check my work w/ a multimeter
2 weeks ago I swapped engine harness from another '93 ATX, along with the ECU and the IRCM…nothing changed. The Gen 1 harness won’t do me much good, in fact I have a gen 1 harness from Devin’s '89…but either way, the mtx engine and atx engine harness are pretty different.
My stock harness was damaged, some wires got pinched in between the engine and the firwall. That harness is the one that was replaced…I thought for sure that, along with the ECU and IRCM would have remedied the problem.
Wonder if I threw it on a dyno or some kind of tuning program from one of the local places (hybrid, innovative, etc) to get readings of things like ari/fuel, spark, timing, etc???
I could…but I want to find out the problem before I keep swapping parts into this thing. I’ve talked on the phone with the few other guys from the shoforum who did the swap after I did mine using atx electronics…so it’s not completely necessary to use mtx wiring.
Also, it’s kindof a bitch to run the mtx harness…all the front accesories change, motor mounts, AC, etc…
I changed the belt about 5000 miles ago when I had the engine out to do rod bearings. Before removing the belt the timing was on. This problem is wierd…yes, it feels/sounds like its a timing issue. But everything checks out okay; timing, plugs, wires, dis, coil, etc. Again, no codes are thrown…it feels like it’s running in limp mode.
If I unplug the mass air while the engine is running, nothing changes. I’ve swapped mass air meters, nothing changed…runs the same. But there have been times when I’ve unplugged the meter and the engine will surge and run even worse. Point is is that just when I think I’ve found something wrong it turns out to not be…I think I may convert the car to a carb.
ALl of those have been checked on several occasions and are in good operating condition. Thanks for the compliments on the car. I wish this car weren’t in such good condition…otherwise I’d part it out/scrap it, but since it’s fairly rare to find a clean SHO, let alone a black on black model, I really want to get this thing running well again.
Haha…been there too:) Since this problem began I’ve had the engine completely out once, intake off at least 3 times, and checked and rechecked damn near every component at least once.
All the those have also been checked…it’s funny because when I bought Fuzzy’s '89 SHO that engine was missing half of the components one would think necessary to make the thing run, like the engine ground strap for example:bloated:
that car was a piece of work that is for sure. i yould like to lend a hand if possible. i can grab devins timing light and we can figure out weither it is a injector or spark problem. I would almost lean twords a injector at this point. i get out of work at 5:30pm give me a call.
Timing has been checked a few times…fuel injectors have been tested both in the car and on a bench. They passed. Thanks for the offer, tonight won’t work for me but perhaps later on I’ll let you be the next contestant in this game of “fix the SHO”!!!
Whatever is happening isn’t a constant…i.e. fouled plug, dead injector, etc. I can clearly see the fuel spray into the cylinder head, plugs are all okay, plug wires all tested good outside of the car.
so you’re still using the auto trans ecu? are their differences in the ecu… ie does 1 have a trans controller and the other not, or are they the same.
how does the speedo and tach get its readings from the 2 different trannies?
i am willing to bet that the ecu has a gear based fuel enrichment table.
you may need want to try swapping to an ecu from a car that had a manual
Weight reduction, can’t have any unnecessary wiring now can we. Honestly I have no clue how that car ran much less put down slightly more power than stock consistantly. :lol:
Only other thing I can think of is power wiring to the ECU, quite a bizarre problem. If I get some time though I can run through every part of your ECU harness and see if we can find the issue. Or see what is needed on the wiring end to try the one from my car. If I recall the wiring is not really that different at all from a B9B/X2J to a D4U1 like what you have.
Yes, all ATX electronics. I am one of 3 people to have done the swap this way and the other 2 guys have cars that run normal…so the ATX cpu and wire harness acn work. Speedo plugs right into the manual just like the auto did.
I have swapped the manaul ecu…car wouldn’t even start with it.
