Another 91 Ka problem

[Uniac]

Just finnished the dohc swap in my 90. Start it up, first try, idles for 5-15 sec and dies. Now if i sit there and free rev it, it'll run, but it dies as soon as i get off the gas. It's also backfiring like crazy.

Here's the setup: AAC and FPR only and a short ram intake.

please help me keep it running.

thanx

[DJ_Sunrise]

umm.. check..umm.. hmm.. check ecu for codes? maybe ur timing is bad? check the FSM for the back firing problem.. if u get backfire, you arent getting enough air into ur engine.. check the throttle body, and intake. buy some TB cleaner, and spray both the suckers down, and make sure none of the vacuum hoses connected to the two are leaking. Hope this helps.


~DJ Sunrise

[KevinsS13]

How about trying the fuel filter? &Fuel pressure? Let us knowwhat it ends up being? Mine ran like really horrable before and it was because of the PCV valvle, its less the $10 to replace it yourself. Its tuff to find and reach with your hands!

[Uniac]

fuel filter is new 2 months ago, maybe 5000km on it, 300zxtt filter... i'll try clamping the return line to boost the pressure, see what that does.

I took out the secondary butterflies, think this might casue somthing?

i'll let you know what i find out that doesn't fix it tomarrow, it's late now. I've had enough for 1 day

[Uniac]

well it seems to be backfiring thru the intake and there is a whistle on the inside of the intake mani(side closest to the block) I guess i have a leak in th aac hardline or somthing. I'll pull the entire unit and see whats what.

[GlacierFreeze]

Make sure the intake manifold bolts, holding the top and bottom half together, are tight.