Help, '92 GTP engine replaced, won't start

[crazyd]

Hey all,

Got my rebuilt 3.4 DOHC engine installed, and I'm so close to finished I can almost taste it. Currently it cranks, but it won't start. Here are the diagnostics.

Fuses:
ECM/FUEL: +12V
DIS: +12V
INJ: +12V

ECM diagnostics: Code 12, test OK - no other codes

Fuel check: 4 gals fresh gas (total at 1/2 mark), pump runs, good pressure at schrader valve on fuel rail

Spark test: Tested on cylinder 6, arcs to ground when cranking.

New Bosch platinum spark plugs and 7mm wires.

Next troubleshooting steps?

Thanks,
Dave

[dohcfiend]

figure out what code 12 is.

did u connect all your vac hoses correctly? no codes? do u have a scanner?

if so check to see if your tps is operating correctly by pushing the pedal and watching the throttle angle value. also get your test meter and check for +5v when the ign is active.

also check your map for +5v

check your injectors pull your rail and turn on the ign to get your fp to pressurize the rail, do any of the injectors leak?

check the other 5 wires.

oops got company be back later if i can think of anything.

[crazyd]

Code 12 means ECM diagnostics are working. I don't have a scanner here. I believe I've sealed all the vacuum leaks and I am reasonably confident that the vacuum lines are connected according to the emissions diagram...

[dohcfiend]

ok, next try holding the throttle open some when cranking it. any luck?

u check all your fuses?

check all 6 wires for spark?

[crazyd]

Okay, I checked the front three (2,4,6) for spark and all of them were good. Removed #6 and checked for fuel, and it was wet with gas after I tried holding the throttle open during cranking. I've checked all the fuses on the passenger side box in the engine compartment and they're all good. Are there any other fuses to check?

There's not even a hint of it trying to fire - no cough, no sputter, no backfire, nothing.

[dohcfiend]

interesting...... only other non-invasive thing i can think of is to recheck your firing order on the coilpacks. 146325.

if u have checked everything above with no avail, you are gonna have to start going into the engine some.

pull the rail and check for a leaky injector as that will certainly cause a no start. after that you will have to verify your cam timing. pull both of you valve covers and rotate your engine to TDC.

to do that there are 2 marks which must be aligned. one is a notch on your crank damper and the other is on that large aluminum casting on the front of the engine, it looks like a little triangle and it is approximately in the 1-o-clock position.

after doing that look at both of your cam banks, they both have flats on the cams themselves. the even bank(246) has them in the front closest to the belts/drives/etc and the odd bank (135) has them in the back closest to the brake booster/master cylinder/etc.

with it set to tdc the flats on one of the banks should be facing up and the other should be 180 opposed facing down, rotate the engine to tdc again and they should switch whereas the bank that had the flats up now has the flats down and the bank that had the flats down should have the flats up.

if not your cam timing is off.

are you getting good oil pressure? if you have no oil pressure or the sensor is broken or not hooked up the ecu will not allow the car to start or so they say. i do not think this is the case b/c supposedly it terminates the fuel pump circuit and u say you are getting rail pressure.

other than this lookup other no-start threads and see what their resolutions were.

if none of this helps i am sorry to say i do not know anything else and you
may have to take it to a mechanic.

p.s. the leaky injector is my guess.

[crazyd]

Okay, I pulled apart the top end to expose the cams. Are the cam flats supposed to be pointing directly away from the heads, or can they be at a bit of an angle? At TDC with the intake valves open, the intake and exhaust cam flats are in sync on the odd bank, but aren't pointing directly away from the heads.

[crazyd]

[dohcfiend]

is that tdc?!!!!!!!!? whoever timed your engine done it all wrong if that is tdc.

at tdc the flats are supposed to be lined up with the casting numbers there facing up and the opposing bank should be facing down toward the ground.

if u can get me a pic of your 2 timing marks lined up on the damper just to make sure u have it in the right spot.

if they are that is your problem. my guess is whoever timed it may have went by marks that were left on some of the lq1's gears.

[crazyd]

Yeah, I figured it out. I used the wrong timing mark on the balancer for TDC to set the base timing. I've gotta re-do it.

[dohcfiend]

your welcome.

[crazyd]

Thanks dohcfiend, but I hadn't declared victory yet. I was out there all day today resetting the timing and following the instructions to the letter, but even after doing that it STILL won't start. Does it matter whether the engine is on the compression or exhaust stroke when you get to step 17?

[dohcfiend]

not that i know of. just go by the flats. put it to tdc by the marks on the balancer and casting. set one bank and lock it in, spin it 360 degrees back to tdc again and lock in the other cam bank.

[crazyd]

That's exactly what I did. So what else would keep it from starting??

[dohcfiend]

i tell you what. tomorrow i have to pull the heads on mine b/c of oil consumption. since it was recently built the machinist wants to look at my heads to check the valve seals.

i'll set it to tdc and take a pic to show you what the cams are supposed to look like b/c if yours still look like that last pic you showed me they are still wrong.

that reminds me, did u pressurize the rail and check for a leaky injector? also with the rail out, you can pull your ign fuse and crank it over to make sure your injectors are firing correctly.