1993 Lexus SC 400 Help?

Tiny
IMFIXINGTOFIXIT
  • MEMBER
  • 1993 LEXUS SC 400
  • 4.0L
  • V8
  • RWD
  • AUTOMATIC
  • 127,000 MILES
Ok so I got this OBD1 nightmare in the shop as a failed transmission problem. Which turned out to be the first of many problems. So to start with, the engine will not idle, you can hold the accelerator giving a slight load and it will stay running, (very poorly) with obvious misfires. The low oil light remains illuminated during this despite having the correct volume of oil. So I pulled the covers to get to the plugs and inspect them, low and behold #5 plug was fouled. Replaced and tested, no fix. Now I started looking to other ignition issues PCV valve hose removed and it would idle fine but still misfire. Wires look new, the insulators look fine. Should I check for plugged exsaust next or injector issues? Or even fuel pressure regulator. I got to admit, pre OBD 2 stuff is a mother to diagnois and I'm just going in circles here lol. Any tips?
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Thursday, February 27th, 2014 AT 6:40 PM

3 Replies

Tiny
KHLOW2008
  • EXPERT
Have the cylinder compression tested.
Perform a continuity test on the plug wires.
Test all fuel injectors.
If only a specific cylinder is misfiring, that would be easier to test.
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Saturday, March 1st, 2014 AT 11:22 PM
Tiny
KHLOW2008
  • EXPERT
Btw, if the oil light is showing, you need to be checking the oil strainer in sump. Quite likely it is clogged.
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Saturday, March 1st, 2014 AT 11:23 PM
Tiny
KHLOW2008
  • EXPERT
Have the throttle body and IAC cleaned, that should help in the idling
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Saturday, March 1st, 2014 AT 11:29 PM

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