Was running good, something happened.(:^(

Talonz82 · 05-28-2002, 11:34 AM

Many of you have helped me along the way, resurrect my 1980 sc from the engine fire, I had it running well, I still had minor cold start issues but for the majority it ran great, last week my gastester arrived, I set the mixture,(my ear wasn't far off). A few days later, my son wanted to hear it run and when I went to start it it would start for a few seconds then die, it did this several times before it started, then it hunted and surged until it warmed up.

Today it wouldn't even start, so I started all over, checked fuel pump and check valve-(good)- Hooked up fuel gauge, primary pressure 75 psi, set cold pressure of WUR to 25 psi at 70-75 degrees, checked cold start valve, thermo time switch etc. Plugs looked good, cap and rotor looked good, I set the timing and checked the advance weeks ago,

After all my checks it started and stumbled along I managed to goose it up to high idle, back firing from the exhaust and the intake poppet valve, I did check each and every injector and they all spray very well, I physically removed and checked the aux air device, last week when I set the mixture I checked the ecu and relay, they both worked fine, the only thing I have done is left the o2 sensor disconnected.

I have to be overlooking something, anything you guys can think of for me to check no matter how trivial please let me know. The weather is shaping up and I want to go for a drive so bad!!

Jdub · 05-28-2002, 11:51 AM

Dumb one, but do you have a popoff valve that is stuck slightly open? Any possibility that your airbox is cracked (can you get a fingernail under any of the screws holding it down?

Sorry not to be of more help,
John

Talonz82 · 05-28-2002, 05:10 PM

I've searched each and every cranny for vac leaks and even the possibility of a improperly routed line, I can't understand why it was fine just a few days ago, and then like overnight it goes haywire, thankyou for the thoughts.

s2per · s2per's Garage

I'm going to watch this thread closely, since my SC started a similar very difficult to start problem a while ago. Until she's warmed up a little, coughing and backfiring are the norm (love that popoff). I also noticed my problem began about the same time I installed my 74 exhaust--without an O2 sensor. Hmmm...coincidence?

rstoll · 05-28-2002, 06:01 PM

Sounds like you guys may have leaned them out a bit too much with the O2 unplugged.

Talonz82 · 05-29-2002, 02:58 AM

I was thinking that way myself, I used my gastester (gunderson) and set the mixture when the engine was warm, o2 disconnected to 3.5, when i first hooked up the tester it was at 3.0, I only made a minor adjustment.

Today I am going to remove the freq valve and inspect, also recheck my lamda relay under the seat.

I'm down to 1/4 tank of gas, you don't suppose.......

dickster · 05-29-2002, 03:18 AM

the 02 sensor only works when warm as i understand it, so shouldn't be that?

whats the fuel like? do you know for sure that it is not contaminated?

i know problems like these can be one of a million things, but i have had water in fuel giving thise symptoms. its easy to check, just drain some into (direct from bottom of tank if poss) a glass jar. see what you find. you'll spot water easily as it won't mix.

might be worth a shot

Talonz82 · 05-29-2002, 04:07 AM

I think the condition of the fuel is a factor, it had almost a full tank when I got the car, and whom knows how long it sat, I put 5 gallons in and some techron and since then have run it down to 1/4 tank, I wanted to check the fuel tank screen anyway, so I'm off to check that first.

thanks any ideas and i mean any...are greatly appreciated.

Pete

dickster · 05-29-2002, 04:53 AM

if the fuel is that old, flush the tank out and put in fresh stuff. petrol doesn't like sitting around idle.

seems quite likely to be contributing to your problem imho

Talonz82 · 05-29-2002, 05:20 AM

Flushed the tank, at 1/4 tank I drained 7 gallons out of that thing, very little sediment and no water, went to the gas station and have 5 gallons of fresh fuel and techron, lamda relay working and I can hear freq valve buzzing, off to prime and try to start.

dickster · 05-29-2002, 07:39 AM

what happened??

Talonz82 · 05-29-2002, 11:22 AM

went to the start mode and it coughed and sputtered to life, I had to play with the mixture to keep it running, it smoothed out basically after a few and I hooked my gas tester up to reset the mixture, since I had it running I unplugged the lamda (ecu)relay, no change in rpm or sound.

I reset the mixture to 3.5 let it get good and warm, shut it off, came back 10 minutes later and same thing.....start right up then die.

So I look at bosch book T/S chart and it say fuel distributor, lamda relay, or ecu, so I bench check my lamda relay it checks out good, funny thing, I always thought it had power when ignition switch was in run, mine only works when starter cranks, (I'll be looking into this)

I'm in the process of running tests on the ECU and I think what will it do if I try and start with out lamda relay and ecu hooked up....well guess what, it started right up, runs kinda flat, but it starts right up and stays running.......

dickster · 05-29-2002, 12:39 PM

gotta be good then, right (you're getting somewhere - but i don't know where!)?

Talonz82 · 05-29-2002, 01:23 PM

Yes, at least I think I have a starting point, I know each component in that system, now to narrow down which one is causing the fault, I hope it is not the ecu it'self.

does anyone know if the 1980 sc came with an rpm relay? and if so where is it?

I still need to figure out when the lamda (control) relay gets its power, most threads point to the dome light circuit, that would give it power all the time, (mine has this at pin 30) I can't figure out why it only energizes when the starter is cranking, which would make it's removal while engine is running to hear a difference, useless.....

hhhhhmmmm .....off to test...

Pete