i was out cruising and got an SES light it turns off when i shut the engine off so i didn't think much of it until it happened again. once again it turned off when i shot the engine off so i pulled the codes and got 53. i didnt have this problem last year but i barely drove the car at all. i noticed the vacuum source for the EGR was plugged in a spot that had no vacuum so i switched to an active vacuum source and the code still came back. what would be the next thing to check out? i have read people have problems with the connector wiring, ECM, or the solenoid itself

 

I got the 86 LG4 myself, always had code 53 whenever the car was out for more than 20 minutes. Like clockwork.

It's an over-voltage code, but it's notoriously related to the EGR system.

I replaced my EGR valve, and that didn't do anything. Could have replaced the EGR solenoid as well, but never did.

Believe it or not, when I did the camshaft that code went away. Haven't seen an engine code since, even when car has been running for over an hour. (I got other issues now, but that's besides the point)


Not suggesting you replace the cam though. The EGR is the place to start. The valve and the solenoid.
Code 53 isn't a particularly nasty code though, so I wouldn't worry at all. Your car won't care.

 

i know my EGR valve itself does not actually work since last year when i removed it and applied vacuum the pintle did not move, but the ECM does not moniter the function of the valve just if the solenoid is properly working so ill try replacing the solenoid and see what happens if i can find one. anyone know a link i can get one?

i know the car doesnt care since she still ran like a top but SES lights bug me and i cannot stand them on. anytime it comes on i have to fix it

 

i was searching for a replacement solenoid and ran across this thread
https://www.thirdgen.org/forums/tpi/...-solenoid.html

since the solenoids are discontinued another member took a solenoid off a 95 Cadillac DeVille and an LT1 connector pigtail and put them on his car. problem is his car was an 88 GTA with TPI. can anyone confirm if this application would work for the older LG4s? i would rather spend money on a brand new part then spend 80 bucks on ebay for this 30 year old part that could fail at anytime

https://www.ebay.com/itm/223275251090