CJeep77

Hello all, this is actually the first time I have logged back in here since 2005.....I am now working on my dads 68 Camaro that he has installed a 350 TPI setup into it. We are just getting the engine running now, but it is not road worthy yet. I am currently stumped on an engine issue, and looking for your help. This is an 86 TPI that is converted to speed density. Pops bought the Street and Performance conversion kit that included the 16198262 ECM, harness, EGR delete, and cold start injector delete. The engine is a (supposed to be) stock 350 from a 70's truck that had a Q-jet on it. The '86 TPI unit had 24 PPH replacement injectors in it when it was purchased, but all else appears stock on it.

Issue: when the engine is started cold and in open loop, it runs real rough, and seems to be rich. Once the engine reaches operating temperature and goes into closed loop, it appears to idle and rev fine, but then again I am unable to road test at the moment for a real evaluation. The BLM value in closed loop at idle is around 138. Running at idle in closed loop, the timing shows to be 18-19 degrees.

I have checked and replaced the IAC with a known good one.
Base timing is set at 8 BTDC.
TPS sensor voltage reads 0.62 at idle.
CTS voltage reads good.
MAP sensor voltage reads good.

The ECM has a custom programmed MEMCAL from S&P (which I have pulled out and read to see exactly what was done to it). The injector size was changed from stock #22 to #24.9, the TCC speeds are slightly adjusted, flags set for no EGR, ect, and some very minor adjustments made to the fuel table.

Is there something on the spark advance/timing/distributor I need to look at?

I will be glad to get any additional specific data if it would help you with assisting me

Any thoughts???

ntomsheck

iTrader: (1)

Sounds like they played with the VE tables and warm up enrichment a little bit too. If you have the ability to pull the tune, I think you'd have the ability to edit and re-burn the tune. If you do, then you know where to start.

CJeep77

Thanks Douchermann, my past experience is on TBI, but ready to learn something new..... I think my best plan at this point is to set the tables back to stock values and start tuning from there.

ntomsheck

iTrader: (1)

Would be a pretty good idea. Just make sure you keep your switches like EGR and AIR off, and injector size to 24# Oh also, I don't know if you're putting the 700r4 behind this engine or not, but take a look at the torque converter tables in the bin. I found mine to be way out of wack - torque converter wouldn't lock @ 60mph unless throttle was at 52% (my throttle @ 60mph on flat ground is about 8-9%)

ckelton

Please do not underestimate the Coolant sensor. Since the engine runs off of the coolant sensor, maf, and map. Then closed loop, right off to 02 sensor.

If its running rich, my guess is the coolant sensor reading low temp or minimum temp sensor readings, because of connector issues. Scanner can reveal this, as well as ohms test with the sensor in warm, cold water.

CJeep77

Scan tool shows a correct temp reading climb up as the engine warms up.