No it's the one in the water pump that the computer reads. So you never replaced it? Even so it still seems like wiring or it would do it all the time. Do you have a scanner that can see ECT?

Yeah we have one of the expensive snap on scan tools here (modus I think?).
I swear it can read the last time I farted in the car.
Had it plugged in last weekend and it was reading 157 degrees if I remember correctly. But, I wonder which sensor it was getting that info from. Hmmm. I'll swap the ect in the water pump and see what happens.
I'm assuming it's not opti since it seems ok when it's cold.

Again it should be the sensor in the water pump, unless 95's are different but I don't believe that is the case. The best thing you could do would be to get the scanner on it while it's having this issue and see what it shows for ECT. Or warm up the engine and wiggle the wires to the sensor and see what the scanner shows.

I swear the biggest problem with optis is they cause people to mis-diagnose other problems because they are busy blaming the opti.

The computer reads off the sensor in the water pump, and the sensor in the head is for the temp gauge in the cluster. I just replaced my sensor in the water pump not too long ago, you should be able to swap it out and only lose a tablespoon of coolant. Best way to get at it is underneath the car, and have the new sensor ready to go in as soon as you pull the old one out. Piece of cake.

Yup, changed the sensor in the water pump and it didn't change a damned thing.

Dammit. Kind of at a loss now. Thinking about trying another coil I have sitting here and hoping that helps...

Sensor is in the water pump its a 2 wire. The senderrr in the head is for the gauges. Its a 1 wire.

And hook it up to a damn scan tool so you knowwww what its doing and not guessing. Read data not codes!

I did that a week and a half ago. It told me everything was fine.
Coolant temp was 157 degrees o2's were looking good. Not sure what else to look at or what they should be reading.

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

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

Buy it back then 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?

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.

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......

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

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.

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... :(

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.

hmm, is the egr vaccum or electronic controlled?

Vacuum and solidnoid

I have mitcham5 on damand and access to my tech 2 GM with obd1 cable. But having. Time the weekend. Is all I have so call me hope we can work. Something. Out and l have fuel pressure. Gage.

And egr will run like poo at low rpm but up top will smootg out and it won't cause a backfire or a stumble under a load like he's describing. I could be wrong its happened before but I have diaged tons of stuck egrs and they always stumbled at idle like a cam and then up top smoothed out.

your right pizza on the useless egr.