WHY does it take so long for my RB to start???

[b00stinbmx]

just did a big upgrade of everything, running nistune, z32 maf, gt35r, 740cc d-works injectors. car has fired up fine the last couple weeks, got a rough tune on it now but its getting tough to get it fine tuned and heres why.

during cold and warm starts it takes FOREVER to get this car fired up. i finally get it started every now and then and i can go drive it, as soon as im done i shut it off and if i try to fire it back up literally 2 seconds later it takes about 3-4 different tries of turning the key to get it to fire up. if i let it sit for a while and cool down its even harder to get it fired up. the one thing i noticed is that if i throw my battery charger on it it helps and it fires up a lot easier. i tried playing with cold and warm start enrichment tables but they didn;t do anything. im figuring its got to be a wiring problem. bad grounds perhaps? just wondering if anyone had a similar issue and could chime in. thanks!

[Sileighty_85]

is it slow to turn over as well? if so might need more grounds.

Also check the CTS (Coolant Temp Sensor).

check for Vac/Boost leaks and Spark plug gaps

[Chrischeezer]

do you have a wideband 02? whats your idle a/f?
what your fuel pressure at idle?
what type of fuel pump are you using?

Id check for spark then pull the plugs, during this problem.

[b00stinbmx]

i would think the cts is working right, in nistune its reading fine and not throwing a code. could very well be bad grounds, it does crank a little slow.

[b00stinbmx]

aem wideband o2 , im running nistune and tuning it myself. idle is set fine at 14.7ish fuel pressure at idle is set to stock 43 with no vaccum

[Pro ViZIon]

Yeah check all your harness grounds. Also sounds like your ignition isn't getting a verry strong signal.

[Chrischeezer]

bad grounds really don't happen out of nowhere. and If it was a problem a ground wouldn't get better and start every now and then.

i would figure out if this problem is effecting the basics first, fuel, spark, timing,voltage

[b00stinbmx]

well like i said the car has been fully stripped and rebuild basically and since then with the power upgrades its had the problem. to be honest i thikn the only ground in the engine bay right now is a ground wire from block to frame rail. i should prob ground the head out and maybe ground the harness better, its only grounded to the intake manifold where the stock rb harness goes to.

[b00stinbmx]

i just find it weird cause its literally only during cranking, once running the motor runs fine, no ignition break up, pulls strong to red line

[Pro ViZIon]

maybe a weak coil or start signal for ignition.

[Chrischeezer]

mmmhm.. not a ground then, if it was, it would be a continuous issue, running too

[Sleepy_Steve]

Stupid question, does it still take the same amount of time to get it fired if you let the pump prime before cranking?

[dr.klawn]

i was going to ask about the fuel pump also.... before i replaced mine it took forever to start, especially on cold starts!

[b00stinbmx]

i added a few grounds today, it seemed to help. but not entirely. im going to play with my tune tomorrow with a friend who has tuned a few different set ups and we are going to mess with the cold and warm cranking tables to see if its just simply getting too much fuel. if not i really have no idea what it could be. i checked my fuel pump and relay today, everything looks good, and yes it still does it even if i shut the key on and off a few times to prime fuel pump.

[Sleepy_Steve]

Normally the fuel pump (esp a walbro on an aftermarket ECU) takes a few seconds to prime. Switching it on/off rapidly won't really prime it.

I know on my KA it takes about 3 seconds to turn over unless I switch it to "ON" for about 5 seconds first; then it will fire in about a half second or less.