dam... hmmm yea check the egr make sure the pin moves in and out freeley. before you put it back in when you have it off turn the truck on for a few seconds. it will rev pretty high and be loud but it will blow out any carbon thats in the ports. if the egr is sticking open just a bit from carbon or whatever it will let excess air and exhaust in unmetered. so yea check the egr. and make sure to spend the extra few bucks and get a gasket for the egr that has a screen in it. most likely they will have to order it at the part store but should get it in next day.

 

Did exactly that with no difderence. The valve had a little black build up on it, it moved freely. Seated good. I still cleaned it up but there wasnt much to clean. No chunks. Installed a screened gasket. No change. A friend of mine said my exhaust smells like my cat is bad, ever since the weather got cold my sensamellsmell is useless. My cat has had a hard life, this wouldnt surprise me. Gonna try running it with the o2 sensor out. Also OBD 1 scan tool is on the way, maybe it can tell me something. Yes it shows live data.

 

Well, I took the o2 out of the exhaust and the truck had me fooled for a second casue it ran smooth but then started lopeing again. So I dont think a clogged cat is my problem. However almost no exhaust was coming out of the end of the pipe when i did this, someone told me if all the exhaust starts coming out the o2 sensor's hole if my be clogged a bit. IDK if that's true. Not touching crap till i get that scan tool in unless I hear a really good idea.

 

does it have low power? backfiring maby. you said before it was running really rich. maby the coil is going bad. happened to me. replaced the whole injecter assemble and the lines and still ran bad. idle was terrible. watch this vid of mine and see if it sounds like mine. and im pretty sure obd1 doesnt have live data and will only show you trouble codes when your engine light is on.

 

Ever since i turned the fuel pressure up to 60 it has great power going down the road. Which is what is bugging me so much. I can still try to swap the coil out, i have a spare. The coil is new, I replaced it a while ago when i was having problems timing the truck, the old one was good (of course didnt know that at the time). I also have a spare set of injectors i just cleaned up and may put in just to try. Other than that idk, i'm not sure if my exhaust system is actually ok. I hear the exhaust sound odd like a miss but the engine doesnt seem to skip like the exhasut does. Like a partial clog. It sounded smoother when i had the o2 out to allow an extra path before the cat. It said on the item description, "Equus 3120 Innova Diagnostic Code Scanner with Freeze Frame Data for OBDI and OBDII Vehicles". Rather that's true or not I guess I'll find out.

 

Well a new discovery, after a drive I popped the hop to check if my new water pump seals were holding pressure (it was) and i manually hit the throttle by hand. I heard a soundd out of the intake like a growling or low popping sound like I had heard before when i had the timing off a long time ago (advanced I think, not sure). It's not a backfire. Now I turned it off, put my tools up and a friend showed up. When i restart it the noise isnt there anymore. But after a few drives since then I've verified after every drive it will do this and if shut off and restarted it is back to normal till you drive it a bit. So something is adjusting my timing to a point it shouldnt be i'm guessing. Knock sensor? I'll check my base timing tomorrow when i'm home. Currently at my girlfriends appt. and they dont like people working on cars in the parking lot. With everything i've tested so far being ok, wondering if the computer has taken a crap?

So far new parts are:
complete distributor
coil
plugs
wires
fuel pressure regulator
bunch of vacuum lines
water pump- leaked from seals, may as well replace old rusty while in there
thermostat-old one opened to late

Tested
TPS-ok
MAP-ok
EGR- cleaned and screened
IAC- cleaned niether were dirty
Ect and iat tested good
vacuum is at 17 at idle drops during loping spells
fuel pressure is at 60psi key on engine off
PCV valve rattles

Anybody know how to test an o2 sensor? or a knock sensor?

 

I think for the O2 sensor, you need the scanner hooked up and you run the engine under load to make sure the scanner shows the o2 sensor reading rich/lean rich/lean rich/lean rich/lean and so on. If not then probably needs to be replaced. You mention engine pulls 17 inchs vac. at idle. Is that what its suppose to be?

 

I think 16-20 is acceptable for vacuum. Im going to try to figure out a way to test the o2 with my multimeter. Whay struck me as odd was when i had it unplugged from the exhaust stream and ran it, it never threw a code. I didnt run it that long but it was for a few minutes.

 

yea taking the o2 sensor out of the exhaust wont throw a code unless it was warmed up to operating temp 190f. the computer ignores the o2 sensors before it reaches 190f. do you think its still running rich?? if so try replacing the engine temp sensor. its right by the water pump oulet to heater heater core. that controls the amount of fuel it gets depending on how hot or cold the engine is. also if you think the cat is plugged then drill some holes into the belly of it. it will make it a little louder but no more than the o2 sensor being out. the knock sensor could be bad and throw the timming off. try unplugging it before you start it and see if it smoothes out. cause it should just default and run like its supposed to. the connector might be corroded aswell.

 

So, scan tool doesnt view live data. Bummer... but drove all day with the o2 out and it is running great, just loud. It threw a code only on the first drive. Lean code 44 as expected but all other drives the light never came on. Im spraying pb blaster on the cat bolts every time i get somewhere so i can take it off to check it out. I plan on checking my o2 sensor as well cause i think its odd that it didnt throw a code but once while unplugged from the exhaust. Ect sensor was tested and was reading good as well as the iat. It doesnt seem to be running rich.