SS ninja

iTrader: (1)

Hi guys,

I'm trying to read as much as I can about tuning and boy is it overwhelming!

Currently I just finished installing the FIRST intake setup on a GMPP 330 HP crate motor running with a '730 (I previously had a stock TPI running perfectly on this motor) and I'm having some issues setting the timing, which I'm hoping that you guys can help me solve.

I've got an AutoProm and TunerPro, which I'm only using to datalog right now.

I first fired up the car this weekend and it started up with no problems and idled at 725-750 RPMs in park; no surging or rough idle, everything was great. The motor was set to TDC at #1 before dropping the distributor in, so I figured that I should be good to go with taking the car for a drive after setting the TPS and timing (The FIRST TB doesn't have any way to adjust the IAC like a stock TPI TB does as far as I can tell)

Due to the design of the TPS bracket supplied I was only able to set the TPS to no higher than .67 at idle (which some say is low and others say is high).

I'm also running my fuel pressure between 45-50 PSI right now (Which might be a little too high)

When I disconnect the EST connector to set base timing, the car run REALLY rough and dies after a second or two. However, the car runs perfectly with the EST plugged in. If I advance or retard the timing a little before starting the car with the EST unplugged, the car will fire up and idle, but at around 1400 RPMs. After getting the car to idle, I can adjust the timing to around 8 degrees (According to the timing marker above the balancer), but it will still not idle down from 1400.


With the EST plugged in, the distributor at roughly 0 degrees (I'm eye-balling this) and the car idling at 725-750 I'm getting "Spark Advance Relative to Reference Pulse" numbers that fluctuate between 8 and 13 or so, and my "Spark Advance Relative to TDC" numbers between 17 and 20 or so degrees. My timing light isn't much help at this point, as it's reading 17-20 degrees advanced.


A side issue right now is that I can't seem to record my datalogging as I get an error along the lines of "The log file can not be created" when I press the record button while datalogging, but here's a screenshot of a splitsecond during datalogging (Which really doesn't help too much):



(The knock count was from adjusting the timing a little too much for a brief moment)

So, any thoughts to help me with this? Should I just leave the base timing alone at this point as the car seems to be "happy" where it is and see how the car drives?

DENN_SHAH

iTrader: (1)

glad to hear you got the intake installed

i looked at my FIRST TB, and it looks like you can get a little adjustment out of the TPS bracket.
loosen the bolt holding it to the TB enough and you can move it around some, but i don't think you need to.
i believe my TPS is around 0.70~0.80, so i think your fine where its at.

that one screen shot does help.
some things that do jump out at me.
first is your MAP reading. 3.28 is too high for idle. its rich with that much voltage.
low timing can be the cause of the 3.28 MAP reading.
both your INT and BLM are showing rich too.
with an IAC of 1 at 725, that would cause the high idle speed with the timing up at 8. recheck the closed throttle setting.
if the throttle blade is closing all the way, check for a vacuum leak.

i wouldn't worry about the knock counts, i get a few just from startup.

on the data log problem, did you setup a log file in ALDL setup?
that caused me some problems trying to get a data log.
now i always make a new log file every time i make a log.

when you "Select Log File", make a new folder and label it.
then open that folder and pick a name for that log, i just use a number starting at 1.
later on when your actually tuning, in the Session Comments box, put a note so you know which bin file you used.
also don't forget to keep notes on what you did to each bin and how well that bin worked.
when you get a good running bin, save it and the notes for it somewhere on your pc. saving them to a flash drive or e-mailing them to yourself would be better.
it sucks to get a bin your car really likes and then loose it.

SS ninja

iTrader: (1)

DENN_SHAH: Thanks for the help with the log file, I’ll be sure to try that out this weekend! Also, thank you for the advice so far.

Couple of questions though:

First things first, what would cause the car to not be able to idle at all with the EST pulled? Someone on MCSS.com suggested that I should check to make sure that I installed the distributor with #1 on the compression stroke, although I had my finger over the spark plug hole with someone turning the crank and felt air being pushed out so I’m assuming that I dropped the distributor in properly…


I was able to get the IAC reading to zero by advancing the timing ever so slightly. Is “spark advance relative to ref pulse” a good indication of where the base timing is? It seemed to jump around a couple of degrees with the distributor not tightened down.

Also, if I had a vacuum leak, wouldn’t the car surge at idle?


I’m not sure if the rich condition is also due to my fuel pressure being a little higher than normal.


This is all stuff that I’ll be checking this weekend, but if there’s any more suggestions they would be appreciated.

JP86SS

iTrader: (1)

It does sound like the base timing is real low but the MAP that high at idle bugs me the most. I would check for vac leaks or maybe the hose to the MAP is cracked. That high load indication will richen it up pretty good.
Try to get those IAC counts up to 10-15 so there is some control with the IAC. 1 count is not really controlling the idle. Might need to do the reset procedure to get it going nice too.
Not typing the log file name seems to catch many people when they first try to log.
Good luck.

edit: If the TB is being used with the PCV make sure the lines are not reversed. Need fresh air in front of the throttle blades and the PCV crankcase valve to the port behind the blades. Could try capping the TB ports (not the valve cover outlet) just to test it.

DENN_SHAH

iTrader: (1)

no problem.

a finger over the plug hole works fine as long as you bring the timing mark to 0 after you felt compression from the plug hole.
by changing where the distributor is indexed at, you can actually put number 1 anywhere on the cap you want. but if its not indexed like the factory does it, sometimes the wires won't fit right and it can cause you problems when you pull the distributor or the wires off the cap.

there are a number of things that can cause a stall with the timing set connector plugged in.
timing too far advanced, normally if its that far advanced, you'll notice hard starting, but not always.
problems with the module, pickup coil plugged in backwards on the module, ECM problems, ground problems.
i remember seeing a TBI pickup that would stall when you plugged the set connector in, the timing was too far retarded on it.
and a couple of other things i can't think of right now.

a vacuum leak normally doesn't cause a surge with the 7730.
the IAC is just a calibrated vacuum leak the ECM can increase, higher IAC counts to raise idle, or decrease, lower IAC counts to lower idle. when it hits 0, the IAC is fully closed and the ECM is no longer controlling the idle speed.
you want the IAC counts up around 15~40 at warm idle in park and the A/C off. with it at 0, the ECM isn't in control of the idle speed.
thats why when you bump the timing up, the idle speed comes up.
i llike it around 20 on my car.

the ECM sets timing based on what the base is set to in the bin.
if the bin says the base is set to 8, but the base is really set at 20, the ECM will add what ever is in the tables. if the table in the cell the motor is running in calls for 30 degrees of timing, with the base set at 20, you have 50 degrees of timing instead of 38.
its reversed if the base timing is lower than whats in the bin. if the bin says 8, but the base is really at -10, you have 28 in the in the example above.
thats why the base timing has to be set the same as it is in the bin.

the higher fuel pressure may have a little to do with it being rich, but its better to be a little rich than a little lean.
there is a setting in the bin you can change. you have to figure out what your injectors flow at the higher pressure and then change injector constant. i think how to figure injector flow vs pressure is in one of the stickies.
i think you'll see a lower MAP voltage with more timing, and that will lean it out some.

i'll be around most of the weekend and if i think of anything else, i'll post it up.

edit* JP, good call on bringing up a damaged MAP hose and the PCV, i didn't think of them.

jamieschott

iTrader: (2)

In my case, i had a couple vacuum leaks that helped cause a high idle, about 2000 rpms, tightened a couple bolts and put some clamps on the vacuum hoses and a stiffer return spring and she idles around 825 now.

Although mine is not perfect yet... My speed shop is still trying to figure how to communicate with my chip so they can tune her. trying to get the most out ( DUH , LOL ) my 405 hp at crank rated 383.

I guess they cant find a bin file that is for a T5...

1MeanZ

iTrader: (9)

if they are looking for a T5 .bin for an F-car with a 350 there is no such thing. The closest you'll get is a 'stick shift corvette .bin.

1MeanZ

iTrader: (9)

try this out

https://www.thirdgen.org/forums/diy-...n-vs-axcn.html

DENN_SHAH

iTrader: (1)

Ninja, did you get anything done?

SS ninja

iTrader: (1)

Not too much in the way of progress.

I had previously pulled the runners off the car to fix a fuel leak due to my injectors on the passenger side not being seated properly and leaking gas everywhere, and two of the upper runner gaskets were a little tweaked in the process, so I’m thinking that might be causing a vacuum leak that would explain my symptoms. I’m going to order another set of runner gaskets from FIRST today and they should hopefully be in this week.

My alternator also starting making a horrible whining sound when running so it looks like I’m replacing that as well….all in all a good weekend.

Anyways, here’s a post on MCSS.com that I made after looking at it for an hour or so on Saturday:

DENN_SHAH

iTrader: (1)

i found your thread on MCSS.
DUDE, your interior looks great

SS ninja

iTrader: (1)

Thanks!

We'll continue the conversation over there so I don't clutter up two messageboards.

SS ninja

iTrader: (1)

Bringing this one back from the dead.


I managed to figure out my timing issues after fixing a giant vacuum leak, and the timing seems to be set properly and the car is attempting to idle at the correct speed.


My problem now is that the car has a really rough idle that gets worse once the car warms up. It'll hunt around the correct idle, almost stall out, hunt a little more, almost stall for a split second, etc....

This is all with the car warming up in park, as I didn't get a chance to pull it out of the garage as the sky decided to open up once I was ready to drive around...



Anyways, if someone would want to look at the log file for me, that would be great. It's a couple of minutes of the car warming up in park, with a quick rev or two in the middle.


As a recap, it's the FIRST injection system on a GMPP 330 HP crate motor, running the '730 ECM.


I attached both the log file and the csv file from TunerPro RT.

JP86SS

iTrader: (1)

Just a quick look at it and I see that your timing is bouncing from 14-23 rel to TDC, Your base timing may still be low and the SA Vs RPM error correction tables are causing the surging. Reducing the values in the lower "error" cells would reduce the jumping to 2-3 degrees.
The BLM is flatlined at 108 so either add some timing at the 100 Kpa cell (if cold started) and match that with the closed throttle table or pull fuel in that area of the main VE table. The excess fuel could be causing some surging as well. Smooth the cells around the idle area so there are no big jumps in SA or fuel also.
HTH

SS ninja

iTrader: (1)

Alright, I'll first check what the base timing is, and then go from there.

The car is definitely running pig rich based on smell alone, and the BLM just confirms it.

SS ninja

iTrader: (1)

So i Just had another thought this morning:

Could a worn distributor gear be causing this?


I'm currently running a small cap HEI and I'm not sure what the gear is made out of. I'm also not sure what the gear on the cam is made out of either. It's the stock cam that came with the crate motor. (330 HP 350 HO from GMPP)


Would anyone know?