A new "my lt1 runs like poo" thread :p

[bottledbird68]

Originally Posted by monytorris

It misses me....I can't believe that motor lasted this long in the first place!

Buy it back then lol!

[bottledbird68]

Originally Posted by ZFreie

Thats the first thing I do now when someones like my cars acting funny. I have a small hand held scanner that wasn't super expensive but gets the job done. to bad its a 95 and obd 1.5, he will need the correct cable. Uness he has a tech tool then nvm lol

Have the right equipment, been there, done that. As far as I can tell everything looks ok.
But, I'm also not 100% sure what everything should be reading.
Anyone have any links to the factory service manual for a 95? Or have one I can borrow?

[ILuvPizzaTimes10]

ok so o2s should be swinging back and forth from around .150volts - ~850volts. in closed loop. you should have little to no knock retard on a rev/under a load. get a gauge on the fuel line that you can see from inside the car. i have one from advance thats a universal with a long enough hose i tape it to the wiper and go for a drive. ~45PSI and Never bellow 40. even up top Wide open. wen its hot and acting up get a spark gauge and see what the jump is right out of the coil and then what it is out of the opti. should a gap jump of almost .5" out of the coil and a SLIGHT drop out of the cap. about a .05 drop. and not for nothing but anytime ive seen a car do this after warming up its been a hot coil thats opened/gone up in resistance. or a bad regulator.

[bottledbird68]

Ok, changed the coil and icm today. No change.

Plugged in the scan tool again, o2's are switching fine, coolant temp reads like it should, and it still breaks up and backfires.
It will rev freely with no load but as soon as I try and take it for a ride it's just getting worse and worse.
Don't really think it's a fuel pressure issue since it's blowing occasional black clouds lol.

I'm fucking lost and I need this fixed like last week... Grrrr......

[Motaboata]

opti?

[bottledbird68]

Originally Posted by Motaboata

opti?

Only does it when warm, not cold. If it were the opti I would imagine it would be constant.
Plus it's an msd opti with maybe 20k miles on it, not some parts store or eBay junk

[ILuvPizzaTimes10]

Check fuel pressure. If the pump is failing it will move less volume. The ecm will compensate for it with duty cycle on the injectors. And then wen the pump catches up it will puff balck like a mofo. Or its spark/cap related.

[SLP IROC-Z]

plug wires? plugs? sounds like the car runs good in open loop but once in closed loop it runs like shit, so possibly sensor related. egr deleted on that thing?

[bottledbird68]

Originally Posted by SLP IROC-Z

plug wires? plugs? sounds like the car runs good in open loop but once in closed loop it runs like shit, so possibly sensor related. egr deleted on that thing?

Plugs and wires were new last year. All the wires were double checked and look good.
And yes, seems like when it goes into closed loop it runs like ass. Egr valve is still there but unplugging it makes no difference. Nor does it set a code so I'm assuming it was deleted in the tune along with the air pump and other emissions bs since unplugging all of that never set a code.

Need to sort it out before my buyer walks...

[ILuvPizzaTimes10]

That's why she's upset. Your selling her!! Ahhh haaaa. Unplugg both o2's. Will keep it locked in open loop. And see if it still does it. This way you can determine if its heat soak or loop related.