rojas1826

ok i have my 86 iroc z is running like crap cause i dont have the o2 sensor in it due to some cheap headers from jegs that i bought and they dont have the hole for it. i did vortec heads and a xe262h cam and now when i put my car in reverse or drive from park occasionally it will turn off is it the lack of the o2 or something else?. so i have to feather the gas just a bit to keep it from dying. also my fans always stay on for some reason and im not running a thermostat so should i get one on. i took it off cause i was afraid it was running too hot. but even w.o shoudnt the fans be off when its cool? how long will they last if there always on?

Rolling Thunder

Yes you need an o2 sensor. This is especially true because youve done mods and im assuming you havnt reprogrammed the ECM to match which means the ECM wont be able to correct that A/F ratio. Like this the car will never run right. Not to say thats your only problem but there's not much point in talking further till you get that in order. You do need a thermostat in place and the fans should turn on and off with temperature. If they run on forever like that they will have a significantly shortened life. I would go to the fan relay and unplug it to see if it turns off. If it does then you may have a bad temp sensor or a short in the wire that controls the relay. If it doesn't turn off when the relay is unplugged someone probably rigged it up to run constantly which is sadly common.

rojas1826

thanks man i will try to get all this done quick

rojas1826

aww man doesnt seem like anyone does tpi tuning here in chicago anymore. i called flp performance there the last ones who still worked on tpi but just stopped recently

Rolling Thunder

Yea there getting far and few between. Not much money in it now. You can still send your ecm to places like PMC For Less (there a site sponsor). I personally haven't used them but from what Ive heard people are happy with them.

rojas1826

i also dont think the guy who did the work for me adjusted the rocker arms correctly would this be an issue and are the rockers too big for these heads cause i know they cant take much lift. the cam has.462 .469 lift and the rockers are 1.6 self aligning roller rockers. i wanted to do this work myself but i cant understand what lash means it supposed to be at 0 but idk how to do this. is this something i can learn easily or should i take it to the shop also. and also could the cam timing be off or would the car not run if it wasnt.

rgarcia63

You can search TGO, or the web for lash procedures use the one your most comfortable with. 1.6 rockers my not help the intake but, it won't hurt to use them on the exhaust valves. This needs to be done properly, or you'll damage something over time.
The ECM should adjust itself to the mods as long as they're not too radical. But, initial settings like timing, IAC, and TPS need to be set properly for the ECM to have good reference data to learn from. Speaking of the ECM, the fan staying on may indicate it's boogered.
Use a chip emulator which will make it easy for you to edit the binary file using data logs to tune, or send to someone to do it for you. You can have someone dump your chip to a file, or download one from the web.

You probably need to change the initial timing, and the ECM needs to know what it's set at so if you had the emulator that would be easy to do.

Let me know if you want to use an emulator.

Rolling Thunder

Well it depends on your heads and how much lift your heads can accept without a problem and how much other work that has been done to the heads. The clearances can be measured though. Valve lash is a measure of the clearance in the valve train. In old cars with solid lifters there would be some gap between the rocker arm tip and the top of the valve stem. On hydrolic lifters though there should be no gap also known as 0 lash (actually 0 lash plus preloaded which means the clearance is brought to 0 and tightened a little more). Its not a difficult thing and its something id recommend learning. Again as mentioned above ide so a search for how to do it because it can be kinda lengthy to type it all out here. I wrote a paper on how to adjust lash and with pictures and everything I think it was like 11 pages long lol. If you find a good site that describes how to do it and have any questions on it though feel free to ask. As a matter of fact when youve read how to do it id even recommend reiterating your understanding of how it should be done to us just so we can confirm that you are correct in your understanding of how to do it.

rojas1826

ok im thinking i might have other problems more than just tuning. like everytime my car shuts off when i put it in gear just before the gears go in a little hard like the car kinda jumps and then it shuts off like idk could that have something to do with tq converter or a cable to trans or something that causes this? if it were to go in smooth then i dont think it would turn off. when i first put the cam in it did go into gear rough even before. it wasnt until about 2 weeks after the cam that the car would die but i think thats cause i messed around with the rocker arms. the vacuums are also bad they are all pinched and this is because i bought new hoses but there all pinched like the one on the throttle body is pinched badly theres two of them and the one on the bottom is the pinched one. the top one is missing so i put a cap on there. then on the plenum passenger side that one is also badly pinched. when i brake(this just started happening today)the car dies and wont idle at all i need to be on the gas just a bit. i might have moved a vacuum or something while putting in thermostat. its in now, yayy!. 02 sensor is also in.

Rolling Thunder

On these cars the engagement into drive from park is normally kinda rough. This was corrected in later 700r4s. If the torque converter stayed locked up I suppose it could cause an issue like that though. Since you said it didnt die out untill you messed with the rocker arms i think a good place to start would be to set the lash on the rockers. Also the vacuum line should be corrected though i dont think thats the problem. May want to check out the IAC.

rojas1826

took my car to the shop today they first found a burnt plug wire which is why it wasnt running good. then the timing was off. so now the car runs and idles like a champ. the only thing to do now is tq converter they said after the cam u need one and theyll charge me about 600 bucks. and another 500 to get all the "ghetto rigged things" fixed cause trust me this car is rigged like no other. gauges that dont even go inside. wires from the accel ignition control are wrapped around the brake booster. things like that. they liked my car they couldnt find any rust other than on the battery but thats just light surface rust.

rojas1826

ok got it a chip from pcm4less. it drives good but still needs t c. the other thing is the backfire from this car when im at about 3-4k rpm and i let go of the gas there is some backfire.

rgarcia63

backfire, or afterfire?

Rolling Thunder

Im assuming you mean a back fire in the exhaust. Thats probably just an exhaust leak not a big deal there its common for a lot of cars.

rgarcia63

If it's afterfire I would still worry about it, but if it's backfire I'd make repar a priority because backfire out the intake can damage a MAF.

rojas1826

its just a quick kaboom and a flame out the exhaust when im downshifting at 38 mph from 3 to 2. it scares people. or when im goin over 70 and keep my foot steady then let go it will do it. i also noticed theres an exhaust leak on the crappy welds in my y-pipe. gonna get it fixed soon. motor mounts are shot. engine is rattling all over the place. i just ordered moroso solid mounts for it. hope it makes a difference.

rojas1826

ok i put a brand new temp sender and the fan is still on all the time, the relay is also new.

rgarcia63

Which sender, driver, or passenger side.
Which fan primary, or secondary?

Rolling Thunder

If I were you I would re-think this. Solid motor mounds will work just fine but every vibration is passed into the car making you feel it all where as a good rubber set will dampen the vibrations. Its not a big deal if you don't care but something to be aware of.

On to the fan problem, I too am curious which sensor you changed as there's one for the gauge and one for the ECM the one for the ECM is the one that would require the change.

rojas1826

would that be the one that goes in the front by the water pump? i havent changed that one yet. and for the mounts, i like to feel the engine makes the car more beastly but thats just me i like obnoxious more i already spent the money so now i gotta live with it but as long as it works its all good. i also checked my driveshaft and it has a little phase going on but not too bad about 5degrees or something, is it junk?

rojas1826

i didnt see any on the passenger side and i only have 1 fan. ill take another look though and make sure, i know theres one in the front by wp.

Rolling Thunder

Yea on our TPI cars there's 2 one for the gauge on the drivers side and one in the front of the TPI intake by the water pump. Unfortunately the one by the water pump is the one that needed to be changed. As far as the driveshaft phasing. I really dont know off hand what the tolerances are. 5 degrees is pretty small though something like that would be hard to even see are you sure its truly out of phase and maybe just looks it? Look over the tube for dents and scrapes but if you don't see any and it isn't causing any problems I wouldn't worry about it.

rgarcia63

I have Polyurethane Engine and Tranny mounts, they're definitely stiffer, but I like them more than the stock mounts. I also replaced all the rubber bushing with Polyurethane.

rojas1826

heres the spark plugs....

rgarcia63

Need clear image of plug only from tip to threads.

rojas1826

well this tired old 305 is coming out. now im thinking of getting a bigger motor for under 1200 bucks. found a 383 for about that price whith 3k miles and a 355 fresh built, the only problem is how would i know they will work.