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View Full Version : SR20 Blacktop cranks, wont run


jscherf92
02-08-2012, 10:32 PM
I know searching is key but i've been trying to track down different fixes and so far nothing has improved. So here goes...

Ive got a blacktop SR20DET in a '90 automatic hatch, ive got the clutch bypass wired up right and ive successfully tested the starter, and all four spark plugs. the throttle body will open without any problems, and ive got fuel pressure into the fuel rail from my 255 pump.

When I go to start it, we get a very weak crank that will turn the motor but wont start or run. Battery is in the trunk but ive got 4 gauge running all the way to the lower engine harness and an 8 gauge running from the battery to a ground distribution block which runs to the intake manifold and the other ground points. Im reading 12v at the starter and the ignition circuit is complete.

What can I do to test fuel injectors to make sure they are spraying properly? What other things should I be looking at that could cause this weak turning without starting?
Right now im suspecting a weak battery, bad injectors, possibly bad MAF sensor, something wrong with the ignitor chip (even with spark on all plugs?), or some other wiring issue that I messed up converting the harness.

I can give any information needed to help solve this, my buddies and I are getting frustrated. Thanks in advance!

jscherf92
02-09-2012, 12:20 PM
Anyone at all?

Pulled they injectors and they all spray in pulses when cranking the motor, the cheap fuel pressure regulator I have on there isnt showing anything on its gauge though. Im gonna double check all of the spark plugs again. Is there a chance I messed up the timing bad enough using all of the marks on the crank pulley, camshaft gears and CAS?

Edwin562
02-09-2012, 12:41 PM
weak cranking always tells me starter going out. have the starter tested. what battery are you using??

jscherf92
02-09-2012, 11:37 PM
Its a newer AC Delco wired in the trunk. Ill have to check on the CCA. It doesnt look like it has ever been installed, but its been sitting for a few months at least.

Nicelyphe
02-09-2012, 11:39 PM
IDK about running that wire size personally. Especially for cranking reasons. Id go like 0 Gauge from your local advanced auto or something. Try starting while having jumper cables on the battery to someones vehicle. Like a truck or something.

Nicelyphe
02-09-2012, 11:43 PM
On another note..Whats your CAS position? Try moving it back and forth slowly a little while a buddy cranks, proper position is in the middle of the bolt holes.

jscherf92
02-10-2012, 02:37 PM
right now the CAS is centered and im having trouble believing that the timing could be so far off to not even start, but im not experienced in this so maybe im wrong. a fresh battery is the next test, we tried jumping it from an is300 and it just dimmed his headlights.

Nicelyphe
02-10-2012, 02:41 PM
Yea, personally I think it's going to be real hard to get a strong amount of power through such small gauge wire at that kind of relocation distance.

jbretz
02-11-2012, 08:15 AM
the gauge size most likely isnt the issue. ive been running 4g from the trunk to motor forever and never had any issues. id check out your maf. also my redtop was acting up and wouldnt start unless it had an air filter connected. i guess it had something to do with too much airflow through the maf and not enough fuel compensation. start there and see what it does

jscherf92
02-11-2012, 03:05 PM
Well i figured it couldnt hurt to run thicker wire, so i got 15' of 2 gauge from napa today and ran it from the battery terminal all the way to the coupler (connecting the old battery terminal wires to the new wire) and i kept the 4 gauge wire on there so its pretty damn thick. Also i added a couple extra grounds from the battery ground terminal in case my distribution block in the engine bay isnt enough. If this doesnt work im going to start blaming sensors, and figure out how to test them individually.

JDMRIDDAZ
02-11-2012, 03:54 PM
u r getting fuel correct
r u getting spark?
r u getting 12v to blue/red to coilpacks?
if so...check ignitor
and attempt to restab the cas in properly

jscherf92
02-12-2012, 04:54 PM
getting fuel, getting spark, ill check that 12v at the coilpacks, and ill play with the CAS again to see if it works. the crank is a little stronger with the new wire and we almost got it to fire up today, i guess it was a deep poof from the exhaust

jscherf92
02-14-2012, 10:31 PM
made some progress today. I took the valve cover off, and removed/reinstalled the cam gears and timing chain to set everything back right. removed the CAS and reinstalled it per the FSM .... and .... It will start with some starter fluid sprayed right in where the cone filter bolts on before the MAF. Unfortunately it will also sputter out and die after a few seconds but at least it will start and run briefly. Tomorrow im getting some fresh gas, and looking into my fuel pressure regulator which might be a peice of shit. so ladies and gentlemen, After a few more adjustments and attempts, this just might be up and running.

edit: when it runs for a few seconds with starter fluid, i get white smoke from the downpipe (exhaust isnt on yet), im assuming that means im not getting enough fuel in, which would also cause it to stop running.

jscherf92
02-22-2012, 12:19 AM
reinstalling the old FPR worked. I know ill have to replace it eventually but at least it runs now. thanks everyone for the help.