Z wont start.

[rustest86]

OK, I've been pulling my hair out for a few days now, I have an 85 turbo cali spec that cranks over but wont start. short story is that it has been sitting awhile but always cranked and run. i moved it recently so to have better access to start working on it. it sat maybe a week and stopped starting. It has spark, fuel pressure, and 12v at the injectors. I have narrowed it down to its not getting injector pulse. if i manually pulse/ground the injectors out or spray some brake cleaner in it, it'll start every time. 2 different ecu's do this, the original cali and a federal. i have ohm'ed the 2 separate injector banks out to the ecu and have even opened the harness up to check for shorts, i cant find anything wrong. could a bad cas make it have spark but not injector pulse? a distributor is the only part i don't have a spare floating around to try. is there anything else that would keep it from firing the injectors other than the cas?
Thanks in advance.

[evildky]

yes a bad cas in the distributor can when bad fire the spark and not the fuel or vise versa. The good news is any distributor form a vg30e or vg30et will fit, you might have to swap the clamp and cap as well but if you cant find one from a z the maxima and pathfinder, truck and minivan can all provide a usable spare.

[rustest86]

i had thoughts about the CAS causing it, i was rulling it out because it had spark and the fuel pump kicked on. i just robbed the distributor off a buddy's pathfinder and what you know, it now has injector pulse.......i know better for the next time. now off to find a good one! thanks for confirming my thoughts and making me check it. im just glad i didnt have 2 bad ECU's.

[rustest86]

Ok so I've gotten another distributor from an 87 Maxima and when i spin it by hand i can now hear the injectors clicking, its still getting spark, and i can still hear the fuel pump cycle. after i installed it it still wont start. I can smell gas now after spinning it over. today ill pull the plugs and see if they are wet, but I'm stumped.

[evildky]

Going out on a limb here but how's your timing belt?

[rustest86]

I've just installed a brand new gates gatorback component set, though it had the same problem before i did the timing belt. I've checked, rechecked, and rechecked again. these are so simple to time. I'll check the plugs and do a compression test this weekend. im also gonna check the fuel pressure, i can hear the pump running but that doesnt mean it has proper pressure. like i said it ran fine before, just stopped starting.

[Dave87]

I used to own a '86 300zx NA a few years back and mine copped out on me while I was driving. I experienced the issues you are experiencing. Went through multiple computers, spark tests, tested to see if the fuel pump worked and everything. It ended up being a combination of a clogged Cat and a bad MAF. You should check those two items out and see if that gets you anywhere.

[rustest86]

i know its been awhile but the weather has been complete crap and i haven't felt much like messing with it. but i pulled the plugs and they're fuel fouled. turns out the fuel pressure regulator was bad, the sub harness for the chts was bad, along with the CAS that was bad. Now I can manage to get it it to start, but only if I hold the throttle and keep the revs over 2k rpm. im going to check for vacuum leaks this week sometime. right now theres now exhaust on the car, straight dump out the turbo. i checked for codes today too and it has codes 23,24,31. i checked the tps and it seems to be set correctly.

[evildky]

ficv

[rustest86]

ficv? or the ficd? i dont see anything in the service manual referencing a ficv.

[evildky]

I forget what they call it on the Z31 and depending on turbo or not it's one or 2 actual parts but ficv, ficd, iacv etc it regulates idle air and or fast idle. The z32 had a lot of problems with their iacv, just clean and readjust.

[rustest86]

well since the weather cooperated i made some progress yesterday. i changed the CAS and it started much better and no long was dumping fuel but still wouldn't idle. i could hear a giant vacuum leak under the upper plenum. i did a boost leak test and it was horrible! the gasket had slid off when i re installed the intake. Numbers 3,4,5, and 6 had un metered air. fixed that and now its starts and idles. it has a mis, but i think its a bad plug from running lean/rich. anyway a bad CAS, bad CHTS sub harness, bad FPR, and a messed up intake gasket