25th327RS

iTrader: (2)

Hi all, I have ran I to some trouble and haven't been able to figure it out. I have a ls1 into my 92 Z28, torquer cam and ls2 heads, ls6 Intake and longtubes. The car ran good from the start, but earlier this week, I needed to move it out of the garage to change the oil in my truck. when I went to start it, it popped out the exhaust a few times and failed to start. It was running fine when I shut it off previous to trying to start it this day. Checked all chassis grounds and engine grounds along with the grounds at the back of the cylinder heads. I have good grounds and correct ign and batt connections to the PCM. I checked sensor wiring with a ohm meter between sensors and ECM once again and all are good.

I cleaned plugs, as they all were soaked with fuel, put them back and have been able to get it started again, but runs super rich, black smoke out of the headers, and will not even come close to an idle. TechII Scantool shows no codes other than EGR, evap, purge solenoid, skip shift, ect. Coolant temp and IAT are reading correctly, O2 sensors appear to switch correctly, zero misfires detected. Just feels very lazy and unresponsive.

Totally stumped, haven't had luck searching this issue online anywhere either. Was perfectly fine one day, and straight to this on another day. Car has not been tuned yet, but ran well. Was hoping to get exhaust done this coming week so I could have it tuned, but I think arranging an appointment for a tune would be a waste of time until this is figured out.

Sorry for the length post, just trying to put all Info out from the start.

Killert

iTrader: (9)

Have you checked fuel pressure?

25th327RS

iTrader: (2)

When the pump is priming, its about 58, when the pump clicks off, it's at 52 or so. Once it starts and is runnig the pressure comes back up to 58-60. Plugs are new AC Delco platinums with new Taylor wires. Fuel filter is also new.

86White_T/A305

When my car was untuned it ran very rich aswell and would sometimes stall but once it was tuned that was all fixed.

I can tell you that even now that my car is in storage..after boosting the battery the car would run like crap as it relearn the trims.then after a restart it was perfect again.Maybe try disconnecting the battery for 10mins or so and then start it up. Who knows..sounds odd what your going through.

STREETDEMON

torquer cam and longtubes aren't helping the matter. even with a mail order flash on my ecu my 6.0l with an F13 runs pretty rich, but it will idle. did you have the rear o2 sensors turned off?

25th327RS

iTrader: (2)

I understand it won't run perfect without a tune. Rear 02s are not shut off, I don't have the equipment to do so, my tuner will do this. The car used to search for idle a little bit, but always sounded good, idled relatively well, and overall seemed fine. It is not suddenly running durastically different, the sudden change is why I believe something other than the tune is a issue.

Battery is disconnected now, will hook back up tomorrow and see if there is any changes.

STREETDEMON

how much run time did you have on it before it started doing this?

86White_T/A305

Disconnect the battery for a few mins is all you need to reset the pcm really.But aside from that..not having a tune and running that setup isnt going to help to diagnose what the issue could be.Stock tune hated my 228r cam and already had rear 02 deleted and no emissions stuff.,i cant imagine what your stock tune is trying to live with lol.

jazzdadss

I hope that helps things for you. The tune may be compensating for lack of Rear o2s?? Hopefully a "Reset" Will get it good for another while. Mine is still a bench tune and runs FAT. once it warms up it hunts for idle and runs REAL FAT! Due to this and the fact that I am cutting up the harness again to make prety, I quit starting it for everyone that just wanted to hear it run. Let us know what you find and good luck.

25th327RS

iTrader: (2)

Been thinking about this in the back of my mind this morning, the only other electrical issue that has come up, is my domelight and map lights I the overhead console stopped working as well. I chalked this up to probably unplugging the harness for this when I was pulling the line guages out of the a pillar. I doubt these are related issues, but I will check into this tomorrow as well to be sure. Most often 2 things going Wrong at once are results of one cause, although I do not see the connection here. I have my o2 sensor power feeds, MAF power feed, and reverse solenoid feed all off the thirdgen emissions ccommon. I don't remember checking g these for 12v when I check coils and injectors for 12v, but I would think the o2s would not switch or function at all without the 12v power, but is another thing to add on the list to look at.

25th327RS

iTrader: (2)

I have probably had only about 1 hour run time before this all started. It always did run rich and did hunt for idle once warm, just nowhere near this. I have a run vid in my build thread, will post another tomorrow for comparrison.

STREETDEMON

if that's the case, i don't think its anything extreme. chances are the ecu is finally getting its mind wrapped around the fact that its missing readings from the rear o2's and whatever else needs tuned in/out. it took my computer a few days of driving to find a happy spot, later i had to pull the battery off and it all started over.

AGearHead4life

I agree with all these guys. Its probably just fouling out the plugs running too rich do to the lack of tune with that cam and no secondary O2s. I had a build do similar before.

I'd hold the pedal to the floor to get air in and thin out the fuel while starting it to get it cranked. Once crank pedal it until it warms up. then let it run long enough to get to operating temp. (About 10 mins) I would hope that'll clean out the cylinders. Its not going to like short runs much. That'll just foul the plugs.

Also, disconnect the battery to reset ECU, like others have said.

25th327RS

iTrader: (2)

I disconnected battery this morning before I left for work, but I wont get to touch it tonight, it'll have to wait for tomorrow. The only way to get it started is to pretty much floor it until it starts, I will keep it runnig tomorrow so it can warm up and see if that helps.

Makes me feel better to hear that its probably nothing, the abrupt change just scared me. It's my first EFI build, just didnt expect it to do this. I actually thought it would run terrible, and get better with time, not the other way around.

25th327RS

iTrader: (2)

The domelight not working was just due to it getting unplugged while futzing around near the kick panel, the lock tab is broken on the connector, so no wondering there anymore.

The car would NOT start once again today. At this point I suppose new plugs are manditory now. Have ign power to MAF and O2s, ground tested good on MAF, but I was showing 6.9 and 8.9 ohms on the ground wires for the O2 sensors. Not really sure if this is an issue, I didn't have any wires ohm out more than .08 when I built the harness. I will buy another set of plugs tonight and see if it clears up for the moment. If it does, I will not run it anymore until it goes for tune, if no change I will tear the harness out and look deeper at the O2 grounds.

AGearHead4life

I'll go ahead and blind gamble that the plugs will get her started tonight!

25th327RS

iTrader: (2)

Was plugs. Old ones still look good even though they do reek of raw fuel. Had plenty of fouled plugs with my carb motors and snowmobiles, but never any that did so in the manor this did. Running perfect, now I can trailer it to the shop this week to get the header collector cut and turned a bit. Too close to the framerail, and the way the shop is setup, it really needs to be driven in, or pushed about 150 feet to the tig station. Feel totally dumb at the moment....

AGearHead4life

Nah man, dont feel dumb. **** we all go through it. Thats why we always put our heads together.

Glad you got it going man.

Wrench on!

jazzdadss

Glad you found the problem. Shouldn't do that anymore once you get it tuned. I know me, I just wanted to hear mine come to life even though I know I am probably fowling my E3s as well.

25th327RS

iTrader: (2)

I didn't know the car had even been running anywhere near that rich, just glad I decided to wait on swapping the injectors until the day it goes for tuning. With the tune, it should be spot on and no more of this. Summit shall be very happy with me, as I just ordered all the cold air intake parts, and exhaust bends, tips, mufflers blah blah blah. Ordered a double hump xmember too, and will use the torque arm mount from my spohn piece to graft onto the hawks piece.

CAI is 4 inch with truck 5 wire MAF, using black plastic tubing from air raid and a cone filter. Once its built, I will fab a box to separate it from the engine bay.

Exhaust will be 3 inch from header to xpipe, and 2.5 from xpipe all the way back with magnaflows behind the rear diff. Wanted to go NASCAR style side exit, but clearance for the exit looked slim with my subframe connectors, and I would have had to go without the xpipe with this routing as well.

Will make an appoint for tune as soon as this is all on the car and finished, should be good to go in a few weeks, and will anxiously be waiting for spring!

Rich92 RS

iTrader: (16)

Dont feel too bad. When I went to fire mine up for the first time I didn't tighten the pcm connectors all the way. Might of been dumb luck that I took a peek at the connectors.

I built an intake shield, if you want to see an example.

25th327RS

iTrader: (2)

You have pics somewhere? You can never see too many examples for ideas. I have seen a few boxed in, most with foam or a rubber seal to seal off on the bottom of the hood. For simplicity sake, I am thinking about just boxing the top in as well, either with sheet metal like the sides would be made of, or maybe lexan like some aftermarket kits do. Nothing set in stone and would like to see more filter enclosures, very open to ideas and suggestions.

Rich92 RS

iTrader: (16)

Yup heres the build thread for it: https://www.thirdgen.org/forums/fabr...d-battery.html

I liked the look of the open sheilds vs the boxed ones. I have a grommet for where the intake pipe passes through the shield, but I had already finished it.

25th327RS

iTrader: (2)

Thanks! I appreciate the link. I like how you used the skewers in the cardboard to map out the bottom of the hood, I may scrap the boxing in the top idea now. Although not much, I am sure using lexan helps to insulate the free even more than a painted sheet metal enclosure.