saftysizrs

so ive tried all the research i can come up with and talked to many experts, not local guys that say they know but actual experts, all i can get for an answer is "that weird" and i was hoping for some insight for anyone. so anyway to get to the problem ive rebuilt and did a street port, added a larger turbo and a haltech platinum sport 1000 (with more odds and ends of course). now ive had issues starting it. i have plenty of compression fuel spark and had the base tune done by neslion, ive checked and triple checked everything for a couple years now and the only issue that i can think is possibly something in the harness. it seems to run a little faster then the starter while cranking as if it wants to start but never does. and to the weird part the timing seems to move progressively forward as i crank. has anyone else dealt with this moving timing before or have any insight as to how it might be caused?

RotaryEvolution

iTrader: (30)

could be any of a number of things, including your tune.

first i would start with the crank sensor, since it usually has an extremely weak signal on crank and picks up noise from the starter. close the air gaps in the crank triggers inside the CAS by taking the lid off and loosening the screws holding the pickups to the housing, take an initial reading then cut it in half and set them there.

now you have to consider someone may not know how to set up the haltech base timing properly. you can do this 2 ways, by leaving the CAS to default timing that the stock ECU used and compensating for it with the haltech, or leaving the timing locked in the haltech and adjusting the CAS to compensate.

i do the prior with base timing, set the CAS as you would when stabbing it or leave it as it was originally timed with the stock ECU. go into the trigger setup and you will normally have a 10 tooth offset with a 57-58* angle from home. use a timing light to verify with the timing lock set to on inside the ECU(software), adjust the angle if the timing does not match the pointer. if your CAS is locked at the end of its slot, someone did the latter which i do not like, the ECU also only has so much room to offset the trigger angles. in theory it could be timed right but all of the settings way off.

cranking timing is very important, every engine requires a little more or less than another to make starting easier. generally you want between 5 and 10 degrees of advance during crank. if your pulley is not correct you may have to move these numbers a bit either way, feeling when the engine is liking either more or less timing while cranking.

also, if the base fuel tables for 0-500 are off in the 0-15"Hg range it may not be getting enough fuel for a quick start to get where it needs to be.

cranking RPMs should be set to about 250-300 RPMs, this is the point where the ECU thinks "ok i'm done cranking and now it's time for the engine to take over" and post start tables are used or basic fuel/timing tables.

lastly, filter the home and triggers to level 1. this will buffer the signal to avoid noise interference. too much buffering and the signal becomes lost again so i wouldn't try level 2 or 3 unless it really seems to help somehow.

for more help this probably belongs in the haltech section, i'm still somewhat of a novice with it.