79 280zx - fuel fouled plugs

[bbrownx]

I just bought this car and towed it home - it's been sitting for 2 years - with a bit of starting fluid I got it to start up and run rough for a few seconds. Anyway it won't start up and all the plugs get fuel fouled right away. I get great spark - replaced all plugs, wires, cap & rotor. Anything else to check?

[evildky]

chts, it's located int he base of the thermostat housing, it's the one wiht 2 wires and looks like an injectr connector, a bad chts causes excess rich condition, also a bad O2 sensor can cause a rich consition, and a maladusted afm can also cause a rich condition

if it starts ok then follds out, I thinkt he 79 had the cold start injector, it's mounted right next to the throttle body and has a fuel line goign to it, you can try unpluging the electrical connector so it can't work

[bbrownx]

I disconnected the chts plug - no change, the i removes the fuel line coming from fuel filter canister to the top line into the fuel rail. it started up and idled while it runs - that removed line dumps serious amounts of fuel into a bucket - wont start when hooked back up - still "overfueling"
Modified by bbrownx at 7:13 PM 9/21/2009

[evildky]

uh, I think you misunderstood, the chts needs to be hooked up, if it's disconnected or non functioning it greatly increases the injector duty cycle dumping way to much fuel in the engine, if disconnecting it makes no difference there is a good chance it's bad

uou might also want to verify the fpr holds vacume and that teh fuel return line is clear

[bbrownx]

return line clear - hooked back up chts (not sure how to check it) could there be a relay bad somewhere causing injectors to stay open or something?

[evildky]

fsm details testing of the chts but if unpluggig it makes no difference once warm, it's pretty clean it's bad

[bbrownx]

had a sugesstion to replace ecu - did that and now it's starts right up, but backfires consistenly and if i try to give it gas, it just about dies. could this still be chts issue? checked the plus wires to ensure i didnt have any backwards - adjusted distributer a bit to see if that helped - didnt (back to old position)

any ideas?

[evildky]

yup, could still be the chts, O2 or any of the other issues I already told you to check

are the plug wires in good condition with no cross arcing? somtimes when they go bad they arc to each other or another part fo the engine instead of the spark plug

uou said oyu adjust the distributor and bit and otu it back in old position, did you check the ignition tiing? unless you have a timing light on it you should nto move the distributor!

[bbrownx]

Thanks for the reply - The wires, plugs, cap and rotor are new - no arcing - I put them in the risers to avoid touching the engine anywhere. I guess I will replace the chts and o2 sensor next, I do believe the ecu was one of the problems - as when I hook up the old one, it won't start at all. been trying to track down a FSM - found a 280z FSM from 78, most things look identical - would this suffice to do troubleshooting? Sorry - I'm a noob with an S130 - I've owned 2 240's 71 & a 72 - much simpler!

[evildky]

the S130 system is similar, but the S130 can be had as a cd from courtesy parts, or msa, you can find pdf's online, or pick up a haynes manual at the parts store

from your discription you are fuel fouling the plugs, a bad chts will foul plugs, an O2 sensor will cause the engine to run rich but not foul the plugs

and you did get the plug wires on right? they go counter clockwise from the #1 tower, a lot of people get them backwards

[bbrownx]

Update: changed out the chts module - runs great now, drove it for the first time in 2+ years of sitting. thanks for your help (evildky)

So a further question if anyone has the time - it really smokes - white smoke out of the tailpipe

[DoctorRobert]

Where were you able to get a CHTS for that car? I have a '79, too, but haven't been able to find one...

[bbrownx]

Yes - I found a great place called B&R autowrecking located here in OR - they seem to have anything or can find it. I got the ecu for $29.

Another update. I took the valve cover off to clean it up and polish it a little and noticed a rocker arm completley off the valve and the retainer just laying there next to it. Put it back together adjusted tolerance on it - the car runs like new, no smoke, great power - awesome.I will be taking the engine components off one by one and cleaning/polishing them and starting the overall restoring of the car now that it runs right.

Thanks again for the help.

Modified by bbrownx at 3:11 PM 9/26/2009
Modified by bbrownx at 4:51 PM 9/26/2009

[evildky]

lots of wite smoke? thats generally a sign of a blown hg, it's not a terrible job on these engines but upgrading to arp's will make sure it doesn't happen again