what could be wrong with my 'new' motor?

[EstoMax]

ok so i got this s13 motor installed with all s14 emissions stuff so basically its the same as my old motor except for block and head

now the problem is that the motor starts, but doesnt run right at all, it wants to die if you let go of gas, it stumbles and kills itself usually, sometimes recovers for a few seconds but then stumbles again.

i can keep on the gas and at about 1500 or so rpm and higher it has a rattle in the engine.. i think it sounds very similar to my old motor with rod bearing knock.

i tested compression, its right at 180 across the board, +- 1 psi

could bad timing cause this much idle stumble? i cant even time the thing cause i cant get it to idle, i tried.. the timing gun also only shot in off intervals as if it wasnt picking up the signal, not sure what to point that at, maybe its not sparking correctly but all the spark parts worked fine in my old motor just a few weeks ago

http://media.putfile.com/markoengine1

okMarko

edit:it also did this when i was trying to crank it after i finsihed compression test, then i hand cranked it a few circles and it started up just fine again... wierd ?

http://media.putfile.com/markoengine2
Modified by EstoMax at 10:06 PM 9/12/2005

[gumby]

stupid man's guesses:

pinging?

premature detonation from lean fuel/air mixture

check if timing is over advanced

check egr valve

check for unmetered air



well whatever the hells wrong with it you dont want ping cause itll damage the engine, if thats what it is cause i dont actually know.



Modified by gumby at 6:36 AM 9/13/2005
Modified by gumby at 6:41 AM 9/13/2005

[EstoMax]

my friend took a look at it and his pretty convinced that its the sound of the timing chain slapping against something... the motor sat for 6 months b4 i put it on could the chain tensioner couldve gotten stuck?

okMarko

[frapjap]

That sound is timing chain rattle on the guides...no worries.

In all honesty, redo the timing yourself. I had a "new"95 that had the same symptoms, and my timing was WAAAAY advanced. Take off that valve cover, get the distributor out and time that motor to factory specs(teeth markers with chain markers, the whole shebang). More than likely, thats your issue. Also, check to make sure ALL of your grounds are in place. Every last one of them.

[EstoMax]

how many grounds are there? i even have my own gold plated ground connectors lol.. one from alternator one from back of head one onto the head from harness and one from head to chasses (this i added myself)

but yeah ima rip it apart and redo the whole timing shebang

okMarko