Car not running right after mods.

[1QUICKZ28]

Looking for some help as to why my car won't run right after the following mods and with choosing the right plugs. Also what I should gap them at. Here's a list if my mods.

93 LT1
Stock bottom end
Stock heads mildly ported polished bowl blended with comp beehive springs comp 1.6 RR SA
Stock intake ported polished 58mm TB
.026 head gaskets
Thunder racing cam 230/236. 544/555 W/1.6 rockers
Adjustable FPR 36lb fuel injectors Racetronix fuel pump with hot wire kit
MSD 6AL MSD Vented opti Coil cap rotor wires
Long tube headers switched to heated O2's
AC Delco platinum plugs
PCMforless tune
160 t-stat and jet fan switch to match.

Just got the car back together and ran fine for about 5 mins. Started to run rough like it has a miss and won't idle. I did eliminate EGR, air pump, basically all emissions stuff. Went to vented opti, EWP and double roller timing chain too. Do I need to change gas cap to a vented one? I pulled the air pump relay and with key on had two hot leads. Used one of those to power EWP and one to power heated O2's. Does anyone know if these lose power after car runs for awhile? I don't have a scanner, is there a cheap one I can purchase that will show me if O2's are working? The TB is a professional product, any need to adjust idle screw? Shouldn't IAC take care of that?

I'm trying to throw everything out there to get your opinions as to what direction I need to go. I appreciate any help or thoughts.

[zmm95]

Im pretty sure the air pump looses power after awhile due to tthe fact its only used to help heat up the cats durring warmup, i dont see how having the water pump stop and the 02s stop heating could cause it to not run though... have you checked fuel pressure with that new reg?

[1QUICKZ28]

Car will stay running as long as I keep rpm's up. Seem to run rough though. Won't idle. Didn't check fuel pressure. I'll start there and check to see if O2's are losing power. New to the fuel injection world. Thanks for advice!

[zmm95]

No problem, could be your new throttle body too, some usually have idling issues, you may have to redrill the idle air passage or drill into the blades, what brand is it?

[1QUICKZ28]

My fuel pressure key on goes to 40 psi and bleeds off rapidly. It's an accel fpr. Could it be bad? No fuel in vacuum line. What about check valve in fuel pump? How do I check that?

[1QUICKZ28]

TB- Professional products 58mm

[1QUICKZ28]

Pulled my return line off at fuel rail. Capped it with a rubber vacuum cap and held in place with a small clamp. Key on engine off, Buried the guage to 80 psi. Has very slowly bled to 60 psi. I would say it took a minute to drop to 60. Holding pretty steady now. So fuel pump or regulator? What do you think?

[96lt1m6]

i would instal a stock regulator.....

[jaysz2893]

I had similar issues after my cam install. Need to make sure IAC is opening right and tps is set to .57 mv. Get a obd1 to USB cable and download tunerpro r/t. It is best way for 93 cars. Split blm can cause issues too. Once I got my tune straight it got much better.

posted with my rooted and ICS'd T-bolt using tapatalk 2.

[Badbird_96]

I know its going to sound odd but check the wires going to the temp sensor on the water pump. Its the one that tells the pcm the temp. My formula had a wire break after an opti install and it ran similar to what your describing. Might not be the problem but its another possibility especially if the car starts running rich when it acts up

[rdx]

I just came out of a similar problem. First I suggest getting a scanner ASAP. Try unplugging the electrical connector on one of the o2 and that would make the car stay in open loop, see if the car runs fine like that. I used to have an o2 code and my formula was having a miss at idle and it was stalling just like you said, the new o2 did make a big difference and helped the car stay running, also it worked fine in open loop but it was still not running right, all problems went away when I replaced my opti..

[Fastbird]

I would highly recommend like RDX mentioned, get the car on a scanner. There's any multitude of things it could be.

[1QUICKZ28]

Thanks for all the responses. The problem turned out to be the fuel pressure regulator needed adjusted. Wasn't even close new out of the box. Had a friend stop over to keep car running so I check fuel pressure. Somestimes you just need a helping hand. Also adjusted TPS as mentioned and idle screw. Sounds really awesome!!! Very crisp throttle.