New Rebuild, Starts fine, but dies soon after

cowboyfanatic

New Member
Apr 30, 2007
16
0
0
Oklahoma
I finally have the rebuilt engine back in the car. It starts right up, idles fine, but dies immediately if you touch the accelerator and then let it come back to idle. I can raise the rpms to any reasonable speed and hold it there, but within 30-45 seconds it seems to try and lock up. It takes more and more accelerator pressure to keep the rpms up. The engine finally dies and if I immediately try and restart - the engine is very difficult to crank - like it's under a load. If I wait a minute or two it starts right up with the same symptoms. I don't know if this is a lack of oil issue causing it to start to lock up or something else. At idle the oil pressure is about 10 - 15 psi on the factory gauge.
 

suprabad

Coitus Non Circum
Jul 12, 2005
1,796
0
0
Down Like A Clown Charley Brown
Check your afm, specifically the connection where it plugs into your wiring harness. What you described sounds exactly like a bad connection or a malfunctioning afm. It's probably just the connector.
 

DaSuprawolf

Im SICK of N/A
Dec 29, 2005
456
0
0
ChicagoLand
if the afm wasn't working it shouldn't run that long. i forgot to plug mine in once and it started fine but only ran for like 1 second.

maybe a fuel problem? GL
 

cowboyfanatic

New Member
Apr 30, 2007
16
0
0
Oklahoma
when i first started it, i had forgot to hook it up, it would start and idle, but if you touched the gas it died. hooked it up and she would rev just fine. This problem is more of the engine getting tight inside or something. Is this common with new engines or part of the break in period? and also, my oil pressure is up to about 15-18 psi, so it seems to be getting oil ok
 

cuel

Supramania Contributor
Jan 8, 2007
1,536
0
0
Baytown, Texas
Is it gettting oil up into the head? Are you using the correct oil filter? Do you have enough oil in it? If it was the AFM, it would idle ok, but either wouldn't run, or run badly. Sounds like your having a clearance issue. If you take the splark plugs out, and turn the motor by hand, is it easy, or really hard? Did you do the rebuild yourself? If so, after you installed and torqued the mains, did you turn the crank to make sure it turned easy? Did you do the same after each rod? What about the cams? Did you turn them after putting the caps on to make sure they spun easily? Did you use assembly lube throughout, prime the oil pump with oil, and prime the entire oiling system before you started the car?
 

cowboyfanatic

New Member
Apr 30, 2007
16
0
0
Oklahoma
I did rebuild the lower half myself. the head i had rebuilt by a machine shop. I'll double check the oil filter, it should be right though. it turned great when the mains were torqued, it was a little harder with the pistons in, but not hard by any means. I primed the oil pump before i started the car. it should be well lubricated through out. the cams i'm not sure about. like i said the machine shop did the head. but, the valves seem a little loud to me, but maybe that is just me freaking out. the machine shop was supposed to be the best around... but who knows?
 

DMB-87Supra

New Member
May 31, 2007
21
0
0
Northeastern Pennsylvania
Check your grounds. There's a ground or two that goes on the intake manifold if i recall correctly. I'm pretty sure back when I was having the same issue and I went over everything time after time and couldn't figure it out, then noticed that wire hanging down underneath(apparently missed it), connected it and started the car and ran fine from then on.