SilentNuke

Alright, so I just got my 92 SC400 not to long ago, looking for it to be another project car. It's in pretty good condition, minus a few issues that I'm looking for input on. I've searched the forums for some answers, and atleast for the main issue the questions weren't really answer or it was outdated.

Anyways, here we go.

1. So when driving, around 2k-3k RPM roughly around 45-60MPH the car doesn't stay steady when accelerating, it seems as if the throttle dies off and then when I reapply the slightest pressure to the accelerator it jerks or hesitates. I've been told it may be the Idle Air Control or MAF, but I would like an opinion from all you SC pros out there.

Seems like this guy has the same issue:
https://www.clublexus.com/forums/per...around-2k.html

2. Also, My AC doesn't work and I don't believe the heater did when it was cold but I'm not sure. Coolant level is fine. Air blows, with some decent force behind it though.

3. When I bought the car, the previous owners took the stock amp and disc changer. There is power to the radio (the LCD screen is on) but no sound. I bought an OEM amp, and still no sound. I also checked the fuses, and they are all good.


Anyways, I appreciate the future help and ideas. Thanks



Oh and if anyone has an LCD screen for the climate control, I'm looking for buy.

SilentNuke

Bump. Anyone got anything?

durtysc300

Idle air control is for idling. first thing I would check is your tps (opposite of the throttle cables). If that is okay, check fuel pressure

g4ebguy90

Idle air controls can get stuck. Which would leave them part open cause they are a stepper motor. But he should still have a idle issue or surge.

MooJohn

Pull your ECU and check its capacitors. If they're leaking, you'll be chasing ghosts until you get it fixed. Buying a used one isn't much good - it'll have the same problems, either now or soon.

You might need the 12v fuel pump mod. You can test it easily by putting a jumper wire between the B+ and FP terminals in the under-hood test block. If it drives better, a quick search will get you the instructions for the permanent mod.

A 92 should really have all new ignition - plugs, wires, distributors, and rotors. I just did my rotors & caps last weekend and a previous owner had done the driver's side recently but the passenger side was stock. It was a minor PITA but I'm happier knowing I'm good for another 10+ years. The rotor that was original was cracked at both bolt holes and the plastic was breaking apart at the electrode too. There wasn't much more time till it failed completely.

Your AC is probably like mine: has a hole in the line somewhere. Mounting brackets of dissimilar metals means many SCs have leaky AC lines. I haven't even considered fixing mine yet - still have more pressing jobs.

Buy a double-DIN CD player @ Walmart for $150 and don't look back. I didn't like stock radios in 1992; I sure don't want one 20 years later. Forget cassettes - I can now play MP3s on disc as well as USB and it has an aux in port as well. If your speakers are still stock they're all dryrotted anyway

SilentNuke

I'd put in a new radio, but I still gotta figure out why there's no sound. I def don't want to keep the stock one, lol.

And I appreciate all the input guys, I'll start going through the check list and see where we are at. If anyone has anymore stuff to add, please do.

Kalogerus

iTrader: (3)

As for the radio having no sound, it is possible that its out. Worst case scenario is that one of the connectors are bad. Anyway when you buy a new radio run your own speaker wires and your bennissimo! As for the AC you also could be running a bad compressor? Not sure but my Cadillac had the same issue and my compressor was out.

For hesitation check this thread https://www.clublexus.com/forums/sc-...on-issues.html

It could be fuel pump ecu, TPS or something else. That thread covers them all.

SilentNuke

I did check that thread out, but would you describe the hesitation as the same thing as the jerking I was describing? It seemed like the hesitation in that thread was idling or throttle response.

juanikun

iTrader: (3)

i vote on checking TPS first

bigtexlex

im no expert but the stock sc radios have 2 amps if im not mistaking. one for the sub and one for the rest. did you buy the right one? did you check the connections to the speakers. my old protege had a previous owner who thought he needed to have the worlds most tv's in a tiny *** 4 banger. he screwed the wireing harness all up. i just ran all new wires and upgraded to a real deck... i have a complete nakamichi set up for the sc that works ill sell to ya lol

SilentNuke

How much? If it's more then an af system, I may as well just get a new set up lol