I went into the smog shop today (CA) - test center only this year (lucky me) - and thought I had everything perfect. I've only spent like every waking moment agonizing over some very frustrating ignition problems for like the last three weeks. Turned out to be the computer (after a long and sordid search) and the last couple of days the car has been running really well.

So, since I need it smogged somewhere in the next 9 days, i went in today. No problem, I thought. Well, I passed HC and CO2, but failed NO (I scored about 1400 - need to get it under 700 to pass). Now I know I have to swap the EGR - that's probably never been done on this car, but that's not the question.

The real question is this: The guy also failed me for a faulty SES light (WHAT??? It's been working PERFECTLY!!!) because in the course of his testing it came on and wouldn't shut off (I pulled the codes subsequently - 42 and 54 - the same ones I've been dealing with for WAY too long!) Anyway - would his pulling the EST wire to check the timing trigger any codes? Would they be cancelled or removed once it is plugged back in? Or am I really looking at some other problem here?

New Walbro fuel pump, new ignition module, new magnetic pick-up coil, new distributor, new ECM, new platinum plugs (yeah, I know), new ACCEL 8.8mm wires, new rotor, new coil. Doesn't leave much, does it?

Could a failing alternator cause me to have low voltage signals at the fuel pump or at the fuel pump relay? I have recently noticed that while the car is running the stock voltage gauge reads around 12 volts, and with a bunch of accessories or the headlights on it reads even lower, and the turn signal can make it dip and rise in rhythm with the signal...

One other hack (and I really hate southern engineering, but haven't had time to fix it yet) is that the two electric radiator fans are hard-wired to come on when the key is turned on. Oh yeah - and I just discovered a loose connecter (the wire end) on the driver's side that I think is probably supposed to go to the water temperature sensor (will get under and check tomorrow).

Sorry so long, but I'm trying to get this thing smogged and running real short on time...

Jonathan

 

The SES probably came on for the code 54. If you didn't clear the code 42 from before it'll stay for quite some time.

 

I think I may have found the culprit for the code 54. As the fans are hard-wired to run continuously, that has removed that function from the ECM. Another post elsewhere had suggested that the quaddriver is also responsible for handling the fan controls (directs the ECM signals?) and THAT may be why I'm getting the code 54. I am going to get the fan circuits rewired - hopefully today - back into a stock configuration and hope that that removes that issue.

Sigh - these things seem to be a never ending battle.

Jonathan

 

Code 42 is due to disconnecting the EST. This will also set the SES lite until the ignition is off for at least ten seconds. So after the smog guy disconneted the EST to check the timing he should have shut the ignition off, reconnected the EST and then restarted the engine.

Code 54 is low voltage to the fuel pump during initial key on. This is typically caused by the fuel pump relay going bad. If the smog guy did the EST/restart, then the SES could have come on because of the fuel pump relay failure.

Replace the fuel pump relay and do the battery dance to clear the codes.

RBob.

 

That's the conclusion I was HOPING was correct. I've done some more digging, and the 88 350 TPI didn't have the quaddriver, so it pretty much had to be the fuel pump relay or the pump wiring harness (I just swapped the pump). I also knew that code 42 was more of a soft code - I hadn't seen it keep the light on before, so hopefully if I get the fuel pump relay fixed that'll cease to be an issue, and I can redirect him if he tries to fail me on the code 42 alone.

New EGR valve came in today, so will get that changed out tomorrow (maybe tonight?) and hopefully that'll bring my NO down to acceptable levels.

Any other thoughts on getting NO down? Will running premium gas help? (burns slower, less likely to detonate, therefore cooler?) Will make sure I take the car out for a good run on the freeway first to get the cat temps up, and will try and leave it running when I get to the test center

Lot of little things to fix, but overall the car is running really well...

Jonathan