rebuilt engine - barely runs, bad idle, too rich?

[kalla]

Rebuilt my 6-bolt motor. 8.5 pistons, new rods, rebuilt and ported head. 20G turbo, adjustable FPR. I also removed all the EGR stuff and blocked off all the holes in the intake hoses.

Got the motor in and started it for the first time today. Motor cranks and starts, but runs extremely bad (sputtering, missing) and won't stay running. If I give it just a tiny bit of throttle the RPMS shoot waaay up (4000 rpm) and then it goes back down and dies.

I've checked for missed vacuum lines but don't see any. I pulled the plugs out and had a look; looks like it's dumping in way too much fuel; I can even see unburnt gas on the tops of the pistons.

Any ideas on what to look for?

 

[huafist]

What's your base fuel pressure at? What mods? Fuel managment system?

 

[kalla]

stock ECU with no fuel management system. Adjusted the base fuel pressure to stock specification (26-28 psi), checked with fuel pressure gauge.

 

[MattnGsx]

Are you getting proper spark? Did you check timing, timing marks line up? Is this a 6bolt in a 2g? Need a better profile to realy diagnose

 

[joeracer321]

sounds like a vacuum leak to me. check all of your lines and trace everything, you might have missed one somewhere.

 

[kalla]

6-bolt from a 1991 Talon. Installed the timing belt on the motor while it was on the stand, all marks were on the money. I will go check one more time though.

 

[zxdude]

if i remember the base fuel pressure is 37 psi on a 1g and like 43 or so on a 2g and it goes up 1psi for each psi of boost.. when you crank it over after it dies does it act like there is no compression?


if so ( I had the same thing happen to me a like 2 weeks ago) it ended up my lifters would pump up and lock the valves slightly open causing that to happen...


so I colapsed the lifters with a pin cleaned them and primed them with oil problem solved...

 

[kalla]

I did that to the lifters during the rebuild.

 

[92awddsm]

Are you using the stock injectors or larger? If you have larger injectors, you need some sort of fuel control because it will be way too rich without it. Also check the ecu for leaking capacitors.

 

[kalla]

Everything is stock except for what's listed above. Well, a 3'' exhaust, too.

 

[gnes100]

I am having this same exact problem, car is hard to start, like its spitting too much fuel in, then it idols really rough, and wont stay started, but if i give it a lill gas it will run smoothly

 

[kalla]

okay, so I pressurized the intake with my pressure tester and the manifold was leaking like a seive at the head.

took the manifold off and it turns out that the gasket is not the right gasket! It's pretty close, so close that I didn't notice during the rebuild, however it doesn't cover the lower lip of the manifold ...

4G63 overhaul gasket kit = POS !!!!!!!!! hehehehe

pressure tester = your friend

 

[gnes100]

how did you pressure test the manifold?

 

[kalla]

$5 lowes PVC coupling with air compressor fitting, insert into intercooler hose