Frost

iTrader: (45)

Hey guys, I'm helping out a buddy with an LS1 swap. It's a forged 383 with a d1sc, 224/230 114 cam, Fast 90/90 in a 79 c10 and a PCM and harness from a 98 f-bod. 42lb injectors; 56lbs of fuel pressure.

The harness is still factory from the PCM to the I/O such as Camp position sensor, crank sensor, injectors (except their power, this is now to a fuse block), coils and wiring.

I have turned off VATS in the PCM. I ran into VATS on a swapped RX-7 a while back and just set VATS to 'NONE' in the PCM and turned off the code in the DTC list (option 3, no error reported, SES disabled).

I do not get ANY DTCs during cranking/firing.... It hits right away like it wants to start, and RPMs jump to 600-1000 at their peak and immeadiately fall back down onto the starter (if still spinning it). There is an occasional backfire from the tailpipe that is light. I unhooked the MAF just for grins to no avail, same result (though you can see the freq. in the screenshot).

This engine has new and has never been run.

Here is the tune. I would post a cranking log, but it's so small I can screen shot it and you don't have to sweat the config. The KR at crank is just the over sensitive 98 knock setup. Previous cranking attempts do not have this KR except in a spot or two. I can screen shot some other logs but they look the same.

ChucksZ06

iTrader: (9)

crank position sensor or cam sensor. I am assuming you have fuel pressure and power to the coils and injectors. Good luck.

Frost

iTrader: (45)

Yes, you can see the injector times in the pic I posted and FP is about 56 lbs (BIG single pump, fuel cell, return setup). You can see it fire up too for a split second at a time. The crank and cam sensors appear to be fine and I had their error reporting in the PCM set to report those errors at first occurance. Unless there is some possibility of error still with this method of testing?

Frost

iTrader: (45)

ttt...

67pete

I had my engine fire with the starter then when released it to the run position and it would die...found it needed the "fuel pressure sensor signal" to run.

Frost

iTrader: (45)

There is no fuel pressure sensor on our cars though; that's why they go lean with no codes (except a lean condition code if it will actually run) if fuel pressure falls.

There IS a "Fuel Tank Pressure Sensor Signal" pin 11 dark green wire that is the tank pressure sensor, is this the wire you are talking about? If so what did you do? Ground the input? give it +5 ref voltage?

Thanks.

edcmat-l1

iTrader: (10)

Evap system. Ignore it......

Frost

iTrader: (45)

Thanks Ed... Since this swap is into a 79 I'm trying to clean up the harness as well. I had this one tagged as "not needed to run" and left at the wayside in the beginning

Unless someone knows of a problem with VATS not turning off in a 98 like the later years (if so I could build the VATs box with the 555timer IC) I guess all I can think of to be checking is putting the o'scope on the crank sensor to see what it is giving back to the PCM.

rao

iTrader: (18)

24x crank reluctor wheel?

67pete

On my '99 engine I took C2-46(+5v supply) to a voltage divider consisting of a 2.2k ohm resistor tied in series with a 1k ohm which is tied to ground and the common point wired to C1-64. I don't recall any other "problem" like this being mentioned on this site, but this is what I needed to do......

ghettocruiser

iTrader: (17)

When I bought my 99 Donor car, the previous owner disabled VATS before I took delievery with HP Tuners. After installing the motor in my car, and trying to fire it, I got the classic start then die symptoms of VATS. Being desperate to hear it run, I ran off to radioshack. Spent about $10 bucks on parts and built a 50Hz generator. (555 timer). Got that hooked up and she fired right up and ran like a champ. So...I began using the bypass generator as a security device. Had a weather pack connector on it.

Fast forward to about 4 months after that. I get in it, and forget to hook up that bypass module. Car fires right up. I start driving then realize it wasnt hooked up. Started getting a code... P1626. Something about a fuel cut off signal or something. Its like that to this day.

I dont know... weird... But that was my experience.

J.

67pete

Don't you just love computers!

Frost

iTrader: (45)

Most all of the end connectors are gone from the harness we are working with... I know what the +5vdc supply is on the car, but what is C1-64 back at the PCM?

67pete

That's the "FUEL TANK PRESSURE SENSOR SIGNAL" that comes from the tank.

Frost

iTrader: (45)

yes it is.

Frost

iTrader: (45)

ttt...

BigE

iTrader: (2)

I know it's a long shot but fix the IAT sensor. It shouldn't prevent it from starting but it's worth a shot. Looks like it's just not making connection.

rao

iTrader: (18)

Actually the coolant sensor looks dead....

shifty`

iTrader: (3)

this is going to sound really stupid, but ... i've heard at least 5 people in recent months tell me they couldn't fire up, and all they did was tap on the injectors and it fired. something about the injectors freezing? i never asked for an explanation, just tossing it out there.

i had no problems firing up the first time, but i had a hacked harness (wait4me performance) and grounded the **** out of everything.

Frost

iTrader: (45)

In the process of chasing a Gremlin in the fuel system, a stock set of injectors was tried as well.

I will be on it again on Saturday. We have no IAT but I can jam enough resistors in the end of the connector to get the measured "iat" up to something reasonably close.