Alright I’m look for some outside input and thoughts of things to check. I bought a 91 GS for $250 that wouldn’t start and have been transplanting parts from my 91 LS to try getting it to run. Before anyone asks the LS’s body is screwed structurally but ran fine.
The GS has compression, has spark, is getting air, is getting fuel, but won’t start. I changed the timing belt cause it was the OE one and waaay stretched, new fuel filter, new fuel relay, new plugs, new wires. My pro mechacnic buddy and I are completely confused as to why it won’t start and wonderin what things we might be overlooking. I’ve swapped ECU’s from the LS to the GS and still no change.
Thoughts?
And if this thread is in the wrong category, I apologize.
Edit: Timing is set spot on btw.
What is the Fuel Pressure? Is the distributor 180 off and/or wires installed correctly? Is spark actually making it to the plugs make sure the spark is not passing straight through the rotor to the shaft. Also check to make sure that the ignition switch is not acting up in the start position. I have seen old tegs able to be pushed started in the run position but not fire in the start position.
Distributor only goes into the cam one way. you do have a good idea with the ignition switch though…
O.P. when you say timing is spot, im going to assume your referring to mechanical timing right?! sound like your gone throught the bases, might be time for a second go round. is this a complety stock motor or anything aftermarket? what were your compression numbers and are you sure its get the proper amount of fuel spark? more info would help 
Are you sure you have compression? If the timing belt was loose it could have jumped and you might have bent some valves.
I had an engine doing the same thing, I changed out everything you did, even got a new starter because the old one would just “click.” After the starter got changed out, it would try to turn over and almost fire, but it would just keep cranking. It turned out the engine had 0 compression, or just very little, I think the engine bent a valve or 2. It would cost too much for me to diagnose and fix the problem, so instead, I’m trying to drop in a replacement engine.
Have you checked for vacuum leaks, all your ground cables, fuses?
how aboutt checking the battery voltage and your alternator and opening up your ignition switch and make sure its clean and has good contact points…
Yeah you are not suposed to be able to put the distribuitor in 180 off but i have seen it =)
get your coil and ignitore tested if you dont have any spark…
Update: Mechanical timing was spot on, igniter module and coil tested fine. We did a rudimentary compression test after findin out there was air blowing out and sucking into the intake, and it turns out the engine has next to no compression. Many angry words were yelled to the sky at the mechanic the previous owner used. Best guess at this point is the head gasket is blown right below the cam gears as there’s a small oil leak between the head and block there and it dribbles a very tiny bit when we turn it over. Heads comin off this weekend to investigate.
Note to self: Don’t take the words of previous mechanics about anything. -_-
im sorry to hear that man, i hope all turns out fine for you cause i know how you feel right now.
yeah always test for yourself instead of taking other peoples word. i learned that one the hard way haha
Kind of sad, but you have to be real skeptic about buying things now a days.
you dont havepull the head, you could do a leakdown test first to confirm its the head gasket thats actually gone bad.
well at least your car will be running good as new once you replace the gasket.
oh and since your in removing the head it would be nice if you took it in to a machine shop so they can give it a good face lift. lol. refurbish… They can clean it up and check valve seal and maybe new seals.