Burken01

iTrader: (88)

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Ok I finally got my Forged 347 put together with stock exhaust manifolds and ls6 intake and stock injectors hoping it would start right up and idle...

I started it up and it turned over instantly and idled perfect at about 1k RPM for about 5 min or so then it started idleing lower around 850 or so and then it bogged out..

I had good oil pressure and no oil was leaking and I got it up to temperature and everything was going fine...

Then I let it cool off for 30 min and try to start it again and when i turned it over for the 2nd time it started for 2 seconds and then cut off, I waited a minute and tried again and it wouldnt turn over... I waited another 15 min and started it again and it started right up and idled again for 5 minutes, got up to proper temperature and then cut off again...

I have the stock 98 exhuast manifolds on and didnt block off the egr part on them so is that gonna cause it to bog out?

or do I need a start up tune for it to idle properly?

My mods are:

- TSP Forged 347 shortblock (stock crank) eagle rods, diamond -2cc pistons, Arp rod bolts.
- Trickflow 215 heads (59cc)
- Cometic .040 head gasket which would put me around 11.5/1 compression
- Ls6 intake w/stock injectors
- stock exhaust manifolds with no egr block off plates on them with y pipe loosely connected (getting headers next week).

c0ncEpT

iTrader: (4)

Car needs to be tuned period.

redtan

iTrader: (5)

I assume you have a decent sized cam in there?

If so, a high compression 347 with bigger heads and bigger cam than stock will need some sort of tuning to get right. There's no way whatever tune you had on there before will make this car run well (unless you had it tuned for a stock block with the same heads/cam).

Get it tuned, seems like the tune goes bad once it gets into closed loop.

Oh and you might want to upgrade those injectors too while you're at it.

LilJayV10

iTrader: (39)

You didn't plug up the EGR hole when you took it off?

5.3LJimmy

iTrader: (10)

It sounds like you are running with exhaust leaks and have the O2 sensors plugged it. The air leaking to the exhaust will cause a false lean O2 reading and the PCM will dump fuel until it stalls out. Just unplug the oxygen sensors and it should idle well enough to stay running.

Burken01

iTrader: (88)

I called the tuner and he said since im on stock injectors and stock maf that it should start and idle.

I only wanted to start it so i could heat cycle it and set the piston rings before i went and got it dyno tuned..

Once i have a 100 miles or so and gonna get a dyno tune and upgrade to larger injectors while im there...

the reason i didnt cover the egr hole is because i have headers in the mail and didnt wanna bolt the stock stuff up because im gonna rip it all off soon anyway...

gMAG

iTrader: (1)

If you are in fact running rich, keep an eye on your oil pressure. Over time, an overly rich engine will accumulate raw gas into the oil, which will thin the oil and show up as low oil pressure on your gauge.
You can verify low oil pressure/high gas content in the oil by sniffing it.
An oil/filter change will take care of this after the problem is fixed.