1dirtyZ

iTrader: (1)

could it be that the harness is installed with the wrong side on each side( i mean the passenger side bank of injectors and coil connected to the driver side and so on )??? its very possible to flip the harness around.

Rickys S/C Z28

iTrader: (13)

man it sounds like it is out of time??

veee8

iTrader: (40)

Throw a compression gauge on there, you may have a pushrod issue, it didn't sound right while you were spinning it over.

rufretic

iTrader: (37)

I'm 99.9% sure all the electrical connections are correct now. I did try swaping the coil packs over from side to side and it does the same thing. I think the sensors are all good as well, maybe the map because that's the only code it threw but I would think it would still start if it was the map. I'm leaning towards incorrect pushrod length. I knew I should have put a pushrod checker in there but I was in a hurry as always and just threw a set of stock length pushrods in there. I'm going to go pick up the pushrod length tool at the speed shop today after work and make sure they are good. What changes pushrod length? I have the same heads and rockers as were in there before. My head gaskets are now .04 I'm not sure what they were before with the mls gaskets. The other thing maybe is I now have Cadillac race lifters. I thought the deck was the same height on the lsx as the ls1 but maybe that's not the case. I guess I just have to check what length I need.

10secsts

iTrader: (5)

In that video it sounds like very little or no compression. I'm betting you need shorter pushrods.

veee8

iTrader: (40)

Did you change the cam?

bigredhelland

iTrader: (1)

Hey Ruf! Nice project you have going there! I just read the whole thread for about 3 hours so I will be keeping an eye on your build to see how it turns out... Good luck with the not starting problem. I know how hard it can be to work the bugs out of cars at first but dont get too frustrated or discouraged, because in the end it is almost always worth the hassle Good luck workin on it this weekend! Hope she starts for ya!

2000_SS

iTrader: (24)

if it's not an electrical issue, it's the pushrods i would say. as for that $90 crank sensor, i dunno about you, but i'm in pretty well with the O'Reilly guys here, just wait until you're ready to fire it again, go buy the sensor, if nothing new happens, take it back. just don't get it too dirty or broken

a buddy of mine with a fuel injected tuned-port '68 pickup had a MAP go bad, it didn't run worth ****, but it DID run. i think your problem is elsewhere. if you ARE running a thinner head gasket, your pushrods could be holding your valeve open, say .005"-.015," hard to say without knowing what they were before. .005" i could cause no compression, but enough to pop and sputter every 5 or 6 revolutions.

Pushrods are "cheap" and easy to check/change. just because they aren't a sensor doesn't mean you shouldn't be thankful that's the problem. good luck, again....

1dirtyZ

iTrader: (1)

did some digging and found out that an ls1 deck hight is :9.240
and an lsx deck height is :9.255

and just for refrence a 6.0 deck height is : 9.230
(source: wiseco pistons)

now correct me if i'm wrong, but wouldn't the taller deck of the lsx block cause the valve to stay closed? as opposed to a shorter deck where pushrod will seem longer and thus push the valve open?

Fire67

iTrader: (3)

Before you worry about getting the pushrod length tool, just check the pattern with what you have. Put some dychem or even permanent marker on a valve tip, re-install and re-adjust the rocker and turn the motor over a few times... If the pattern wore through the ink is not in the center of the pushrod, you know you need the tool.

FWIW, it can be off a little bit and will still run. I doubt this is your issue. I'm digging now to see if I can find the pinout for the map sensor, you'll just need to compare it to your stock LS1 harness pinout to eliminate that as a cause for the code.

Since you have no crank sensor code, do you have the correct wheel on the crank? Its got to be something related to this since the motor is sounding like its outta time.

2000_SS

iTrader: (24)

he said he checked his crank and it was right. i agree it sounds out of time, like the intake is staying open too long and it's not getting compression. he said he lined the cam/crank gears up dot to dot though...


whatever the problem is, i doubt it's THAT serious, just elusive. i still say check pushrods since it's easy, check MAP sensor and connections. actually, take your MAP off and look inside the vacuum port. it's small, and hard to see really, but if you hold a flashlight just right you should be able to see the little white diaphragm down in there, if the sensor is electronically sound, but still broke, you should see a little pinhole or tear in the diaphragm...that's easy to check, try that...

rufretic

iTrader: (37)

I have a couple more ideas. One, my map is cloged with coolant or a chunk of metal. My intake was full of both. Should be easy to check but I don't know if a bad map would cause it to act this way.

The other idea is very bad but a possibility, relucter wheel backwards from the factory. I've heard of it happening but whould hope I'm not that unlucky. I have a pic of it installed but can't tell it it's right or not. It's a compstar, not sure if they ever had this problem but I know eagle did.

sevanseriesta

iTrader: (34)

wow that would be really bad luck... if that was the case... since the blower is not hooked up even if you got a stock PCM that you know works it should fire no matter what injectors are in there. I know for a fact because I had this problem before. I could drive the car with 60lb injectors on a bone stock tune, with no maf plugged in. I am saying just get a stock PCM and throw it in there to see if it helps. That sounds so familiar that it make me sick. Again can you tell me if the check engine light stays on after you turn the key off for a second or two

rufretic

iTrader: (37)

That's just it, my rockers looked like they were contacting the valve stems just right.

rufretic

iTrader: (37)

I'll check that tonight. If you think trying a stock pcm would help find the problem, I will try yours. Just let me know how much you want to ship it. I'll plug it in, try it and then send it back either way.

sevanseriesta

iTrader: (34)

k I will send it out to you today... PM me your address

veee8

iTrader: (40)

Thinking out loud here... The stock setup uses MAF as primary control with MAP to measure load, if the MAF fails it goes into a speed density backup plan relying on TPS and MAP. Now since you are in SD with the MAF turned off, if it did have a MAP problem, would this thing even be able to run, there would be no backup for that. On a 3 bar map the connector needs to be Black=A, Green=B, Grey=C, on the stock MAP connector it will be Grey=A,Green=B, Black=C. So double check the wiring and check out that sensor.

But....
It still does not sound right while cranking, back in the day I had a problem like this on my LT4 when I had the adjustable rockers too tight hanging the valves open.
A compression gauge will quicky show an issue there. Might be interesting data anyways.

rufretic

iTrader: (37)

Man would I love for it to be the map sensor. The wiring is good because I used the same adapter it had before but it could be full of coolant and metal. I can't wait to take it off and see what's in it. My intake pored out all kinds of fluid, sludge and metal chunks. If some of that got lodged in the map, I'm sure it wouldn't work.

How would I go about doing a compression check?

1dirtyZ

iTrader: (1)

get an angine compression guage/tool. plug it in each spark plug hole and crank the engine for a few reveloutions and read what the guage shows . some one correct me if i'm wrong , but i think on a low compression motor you should see some where around 150 to 160 psi ( i guess it also depends on your cam ). do all 8 and there should not be more than a 15% difference from piston to the other ( actually on a new engine i would guess nothing more than 5% variance).

you should buy that tool, don't rent it . its one of those tools you hand down to your kids later on

rufretic

iTrader: (37)

Well at least it's cheap, $25 at autozone, and seems easy enough to do. I'll pick one up on my way home.