Hi Boysssss,

I hate to admit it, but I'm constantly stalking these forums without ever posting unless I need some major SC help Sorry- but if anyone is willing... I need help!

I'm a proud owner of a 94 SC400 with over 300k. I recently moved from Chicago, IL and drove her down to Rockville, MD where I've had no problems the whole 11.5 hour ride. I've been in Maryland now for about 3 months, driving the Lex anywhere and everywhere I go- without problems. She's my baby. LOL

Anyway, NOWWWWWWW I have a problem. I was driving, going about 40 mph, when all of a sudden after I began to accelerate, I noticed my steering wheel started to shake- and just like that, my acceleration was gone. Luckily, my cousin was in front of me- I called him, asked him to pull over to check it out. He looks at it, tells me he thinks they're my cats, and proceeds to swap cars with me until we make it back from DC to Rockville (about 25 min drive).

I hop online as soon as I get back, and put in an order for two new Catco cats.. when about 4 hours later, I get a call from the auto parts place telling me their outta stock and cancelled my order. So I'm thinking to myself, "What the hell am I doin? Let me see if it even IS the catalytic converters before I go online and start ordering some!"

So I get some opinions. My first is by some guy who likes me (I know, hate me, I used him ). He says he doesn't think they're my cats, but rather, my ignition coils. Next, I take it to a mechanic who rips people off by the second. Told me (and I'm sure its because I'm a girl) he charges $99 an hour for Diagnostics and he'll need at least 5 hours for computer diagnostics only, not including labor or parts . Boyyyy, if you need 5 hours of computer diagnostics, you def don't know what you're doin! I told him, "Just give me the codes and I'll take back the car." After giving me codes, he told me he estimates between $500 to $1500 worth of work- and he was also rather impressed with how well I kept it, even after 300k on it. Mind you, this entire time, my car is not accelerating, I smell gas when I turn it on, my engine is shaking, almost like its sputtering or misfiring, and its real heavy.

Here's his codes (and I punched them in online to define 'em):
13 = RPM Signal
24 = IAT Sensor Signal
25 = Air Fuel Ratio Lean Malfunction
29 = Sub O2S
31 = Air Flow Meter Signal
71 = EGR System Malfunction



So, I limp my car back to the shop I work at, walk outside, and ask my neighbor (an autobody place) if he's got a mechanic. Tells me it'll take 20 minutes for this boy to show. In the meantime, I check both of my ignition coils (unplug one, check for sparks). Both are working fine and sparking.

I call my VERY trusted mechanic from Chicago. He tells me it's the spark plug wires. Says my spark plugs are new and changed, but my wires may need to be replaced, and sometimes old wires will fire off Diagnostic codes left and right that aren't real- and cause an uneven, shaking engine.

Boy comes in (mechanic who we called from autobody shop)- he tells me I need a need a tune-up (but I had a partial tune-up before my move). Says he'll charge me $395 for parts and $150 for labor.
As a recent broke-@$$ graduate, that's exactly how I looked at him. So I tell him, my spark plugs are new, lets just change the wires. He tells me for the wires alone, $165, $75 for labor. Now, I told him to go ahead and order those wires for me.

Now, I hop online, searching left and right for similar problems on here. First one I found says to replace ignition coils- doesn't apply to me. Second guy started talking about cats, but I don't think their my cats for some reason.

Anyone have any input as to what the problem may be? I'm def looking for a reliable fix, but I'm also strapped on cash (who isn't?).

Think it could be spark plug wires?
Any help would be greatly, greatly appreciated.
Thanks in advance!

 

ECU maybe ? ?

 

Check your PM, welcome to DC metro!

 

My first inclination would be to not pay $240 for wires replacement

Hmm... I wonder if your MAF is bad. I would be somewhat surprised if the wires all of a sudden all gave up at once. Even with 7 cylinders I'd think it wouldn't be that bad.

Good luck and keep us posted.
Jonny

 

Fuel filter? O2 sensor? Coil packs?

I'm saying this because a buddy of mine had a similar problem. Turned out to be his coil packs.

 

Might be bad gas? Just to run to almost empty on the tank and let it in a fresh new tank of gasoline from a reputable vendor.

Otherwise, coilpacks on sc400 are infamous for going bad resulting in misfiring.

Also try to reset the ecu and unplug the air meter see how it turns out.

Gluck!

 

Your ECU could definitely have taken a crap, a lot of people have had ECU issues. First, definitely reset it and see.

 

when I got my 92 it was shaking/sputtering when you gave it gas. after a full tune up and disconnecting the AFM it went away. I've been driving it like that for awhile now and it runs fine. I dont intend on leaving it like this but its ok for now. the AFM are going for $7-800 new. or you can try your luck with a used one. or you can try http://soarercentral.com/sc-forum/me...82/256108.html or http://www.fullthrottlespeed.com/ite...=050SUPRA3MAFT it will work with the sc400 since that year supra used the same style afm, smaller but same style, it can be used but needs some tuning according to the support tech
if it is the ecu try http://www.ecmtogo.com/constructionmessage.htm I thought they had them

 

it jumped timing .................. got to hate code 13 pm me when you get a chance our ls did the same thing a rotor busted got lodged in the timing belt and caused it to jump timing pm me and ill tell you to check it....... HAPPY 4TH EVERYONE.

 

I wonder who that guy was! OP, please don't ever pay so much again for parts. That is what we are here for. Second, I am the one the above quote is referring to and I had MANY of your symptoms. You removed the front coil pack and tested it fine? This is a 50 dollar fix and it will make your car run like new again if it is indeed your coil pack. Gas smell from running rich, misfire from the coil pack, shaking engine from misfiring, ALL my symptoms.

 

+2. Your friends so called mechanic is a Total ripoff. I'd just tell him no thanks.

MAF would cause the car to run like crap.

Get on a local dc forum and see if a member can help u out maybe swap some parts try try and determin the prob. Before u go and spend money that doesn't need to be.

 

This might sound dumb but you didn't spray the engine bay with water. If so then obiosly their is condensation between the plugs and wire causeing it to ground.

 

No, I didn't spray the engine with anything.

I removed BOTH coils, one at a time, and both tested fine.

I unplugged the air meter to see if it may have been a problem- but no problem.

How do I reset the ECU?

I appreciate everyone's responses! You guys rock!

 

ECU reset is just a matter of disconnecting the battery for about 30 seconds- turn your key to the on position to be sure any capacitive electricity is drained. Then reconnect the battery and you're ECU is reset.

 

Sounds good, I'll go do it now!