Runs very rich with stock injectord, superram, 55mm TB, 585 lift, 218'ish hydraulic roller, brodix heads, mid length headers, STOCK Prom. Runs better with est disconnected. TPS set at 0.54 volts, idle oscillating betwen 800 -950 rpm, realize it needs upgraded PROM, but many of the connects for emmisons got "lost" during the motor change, could this be causing ecm issues? Disconnected maf WITH NO CHANGE, CHANGED maf and no change. Also auto trans won't shift from 1st. What the hey??

 

You need to get everything hooked up properly and a good tune/injector sizing before trying to run it. Dont want to wreck a new motor. Sounds like some details need some attention

Jim B aka tpi421Vette is expert with those motors maybe he will pipe in, follow his lead

 

You need to get it tuned. Stock chip will not help you.
Auto trans are fun... Hows the TV cable?

 

Forgot to mention, motor ran great with 86 vette with manual trans, chip was custom, biggest change to this setup would seem to be stock PROM, Superam (Highly modified JLR TPI unit in 86), and auto trans. Alos forgot to mention that car idles better with est disconnected. Where to start.?

 

A motor that big wont want to run anywhere near where your stock one did. Need the right injector sizing and a good tune to get you going. Again wait for Jim he can help...Mseven is a good tuner hes visible here a lot too. One thing at a time

 

What injector size are you using? That cam is tiny for a motor that big. Should be 230-240ish. As stated, you need a custom tune or an aftermarket engine management system.

 

Is the coolant temp sensor on front of intake, hooked up to harness ?

Are there any stored codes in the ECM ?

 

All the 420+ engines I do are mainly running aftermarket ecm's. Mick Mseven is the guy to talk to about this.

 

Switched PROM from 86 (same ECM as 88) although 86 was manual and 88 is auto, same exact engine behavior, so...hard to beleive a fat running engine issue this large couldn't be impacted by the PROM that worked really well, 181mph 3.08 rear. The superram could be causing some of this, but I beleive I must have forgotten something minor, that has a major impact, any hints??

 

 

only the bypass code when I reset the IAC a few minutes ago

 

2 sensors are hooked up to the fron of the intake

 

Herre are the sensors (+ the mangled emission lines)

 

Picture posted above ? If I understand, it has run well before in the other car with same prom, and the only change was the intake ? Not sure I could believe an intake swap by itself would make it go that rich. How have you determined the rich condition ?
I would start by going through what is not connected and re-connect. Do you have the ability to put a scanner on the car or datalog? if so see what are the 02 mv.'s doing, I would also check the cts. temp input. If either of those senors are not working correctly that could cause a rich condition.

 

Think he ran his prom with his prior stock motor?!

Tell me you arent running the car like that at 181 mph

 

Engine ran 181 in 86 car. Engine transplanted from 86 manual to 88 auto + superram. Struggling to locate ALDL rs232 connector at home garage for scan. Right now tech1 is the only tool. Injector pulse width oscillated (as did the motor) from 1.8 to 2.5. Oxygen sensor I think was around 400, MAF was 7.5. It did trough a 32 MAF low reading code early on. Seems to get richer each tme I make adjustments.

 

The tech i should be alright unless something is not right with it. For the most part the difference from manual to auto bin should have tcc out of it, and tweaks in iac settings. An 02 reading @.400mv., and if staying there after the motor is at operating temp., would suggest never entering closed loop. This also means a slightly lower than normal crossover point putting the target afr a tick leaner than 14.7:1, but without an lm-1 or the sort this is just an approximation. The 02 mv. input needs to be observed at operating temp. (unless that was at ot.?).
The 1.8-2.5 is reasonable pulse width, should be a bit more stable, but if not entering closed loop etc. there could be other factors causing this. The maf @7 grams (I suppose this what you mean for lack of info) seems low to me for idle. Typically on a bigger inch motor (400+) I see anywhere from 11-14gr/sec. at idle @operating temp. I would check this out as well.
How are you determining the rich condition? On your scanner (not interior guage), does it show that the motor is reaching operating temperature, if not what does it show? What kind of adjustments are you making, that you state are making it worse ?

 

OK, 400 short block has 30 year history, short stroke B gasser, 15 years later long stroke (current 420") Anyway, made 2 timing marks apparently, TDC and max (probably 35 degrees), USED WRONG MARK TO SET TIMING. Now runs very smooth with esc disconnected. Drove for 10 minutes in 1st gear cuz it won't shift, and took the following readings: MAF = 9.5 Injector pulse width 2.1 and fairly steady, IAC = 91 idle = 900 - 975 rpms, temp = 181, Cross counts = 36 - 44 Rich or lean = lean ESC = 0, dash says 11.9 volts?, fuel integrator = 128, block learn = 148, open loop, tps = 0.54, manifold air temp = 124, temp = 181, O2 sensor = 479. Smooth idle when ESC disconnected, rough idle when ESC connected. New scan cable tomorrow, but I think I'm still missing something basic (like the timing mark), Can you fellas glean anything from the above numbers?? BTW, thanks for the help so far! Jim

 

I'd get a datalog on it before you melt a piston.

 

First get the timing back in line (base timing @6* with esc dissconnected then resonnect) so that the ecm/chip can then use the timing curve in the tune. With a blm of 148 would mean its lean and the int at 128, means it is not adding fuel to bring it in line (lowering the blm/adding fuel).
For that idle speed the IAC needs to be around 40 cts at idle (@ operating temp). Opening the tb blade (min air screw, and reset) will reduce the counts and smooth out idle and throttle response.
02 sensor numbers should be moving around more instead of staying at 479. I would pressume this was before entering closed loop as you have posted blm numbers. However if its staying at 479 once at op temp, it woulld appear that it might not be staying in closed loop.
Where is the 02 located ? is it heated or ? Is the car going in and out of closed loop ?

If the dash is showing correct battery voltage (low volts), this would typically have it running richer due to the offset add-ons in fueling (in the chip/tune) based on voltage. If that info is correct and the alternator/battery condition improve and then operate at 14 volts, the car will be even leaner.
The rest of the data posted (maf grms, pw etc.) doesn't look too bad but you really need to datalog and more than likely some tuning. It seems like your data is a snapshot instead of data over time and the car will need some work. Data logging will confirm things like the battery voltage (low or not increasing), the 02 numbers (moving or not), closed loop/open loop, etc.etc.
Other important info would be to know what the fuel pressure is currently set at ?

Additonally, when you do get it to come around, I would be very carefull as those small injectors (based on your earlier post of using stock 22# inj. ) will not properly support that ci. and may go static at wot.