Easy Problem?

[red91sit]

Hi,

I have a 1983 Tercel SR5. I got it for a really good price as the previous owner hadn't been able to get it to run for several years. It turned out to be the fuel solenoid relay was not getting turned on. With this switched it ran fine for a while until the alternator packed up, then the ignition coil, and then the battery. Once these were all replaced it ran very nicely until a few days ago.

The problem first started that while driving it would cut out and I'd have to cut out and I'd have to restart it, but it started right up, so I wasn't worried. Today it died while shifting from 1st to 2nd, and it woudln't restart for quite a while (embarrasingly enough on a bridge). Now the only way to get it to run is to pump the accelerator pump a LOT and then it revs up, but dies if I let the rpms drop below 3,000. I don't think it is a carb issue, as I have cleaned this thing out MANY times, and since it's the whole idle-3000 rpm range that is out, it's not just one circuit that is clogged right? The other thing that makes me worry it's ignition related is the tach drops faster than the engine dies! When i let it go below 3000, the tach drops to zero while the engine still winds down... same with if I'm coasting in gear and the engine dies, the tach drops too (no spark?)

Other than that, this car is lots of fun in the Minnesota winters!

[Petros]

it would be an easy check for spark, when this happens ground a spark plug wire a 1/4" from metal and get someone to crank the engine. A weak or no spark means you found it. Sometimes electrical components will work okay when cold, so it starts okay, but as soon as they heat up from running, it dies out. it means it is about to fail altogether, so you have to track it down and replace the bad part, could even be your new coil (some of the replacement parts come from China and many are junk right out of the box). In the Tercel it has the coil, igniter and other systems all contained within the distributor, I would get a spare distributor from a self service wrecking yard (cheap, only about $12) and swap out the whole assembly. It is a quick and easy diagnostic test.

Another way to verify fuel or spark is to spray some gas or starting fluid into the carb and crank it. If it starts and runs and than dies, it means you have spark but get no gas. There is a low speed fuel solenoid cut-off solenoid (it prevents dieseling when you shut off the engine), it goes back it could cut off all low speed fuel supply. So do not rule out fuel supply issue until you verify it.

Good luck.

[red91sit]

Alright, did some more testing.. and it's running lean once it warms up... very lean. If I pump the accelerator pump about 10 times, then it will fire up and run fine at 3000 rpm, but as soon as it gets below that it dies again. It will idle when cold, if we yank it with the truck, she fires right up and sits putting away around 800 rpms. I can close the choke completely once it's warmed up, and it will idle for a bit, but this should flood it out right? Also, the AAP is disconnected/leaks gas.

This leads me to wonder could it be fuel pump not giving enough gas at low speeds? or maybe there is ice in the carb somewhere? (it hasn't been more than 4 degrees here for some time). My last thought is the thermo valve, but I unplugged everything connected to this with no change (also indicative of a problem I suppose).

Tonight, I shall check for vacuum leaks.

[takza]

Look first on the pass side of the carb (3 lines)...then the vac going to/from the canister...and the brake booster line?

[red91sit]

Well, it's not vacuum line or carb related. I have tried disconnecting all the hoses from the carb, as well as manually moving the choke. The end effect stays the same... it runs for about 20 minutes and then it starts cutting out at low rpm, and then higher rpm, until it just dies and barely restarts until it cools a bit, but won't stay running until it has completely cooled. This had me thinking coil, so I replaced it, and the EXACT same problem?

Is there something elses in the ignition that could be doing this? Or should I try a name brand coil? the previous two have both been O'Reily's specials...

On the upside, it was pushing through about a foot of snow today made me proud.

[Petros]

could be a partly blocked fuel filter. Also a leaky fuel line on the vacuum side of the pump (between fuel tank and pump) could cause it to suck air with the gas, and limit the supply of gas to the carb. Usually this will make it cut out at higher loads (high fuel demand), and it idles okay. It sure acts like a vacuum leak, did you check the tighness of the intake manifold? The nuts work loose sometimes, and under the carb too.

If you have good spark, it is not likely ignition. Did you test the low speed fuel cut-off solenoid? This cuts off fuel on down shifts and when you shut the engine off, if it is failed in the closed postion it will starve low speed fuel supply.

Good luck, and merry Christmas.

[red91sit]

Thanks for all the help...

The solenoids I have setup on a switch, and I can hear them both clicking. The car can also run around 1200 rpm when I first start it, and turning this switch off kills the engine. So this seems to check out.

As far as the vacuum leaks go, I havne't tried retightening the manifold-to-head and carb.-to-manifold. I tried disconnecting all the vacuum lines from the FSV thinger, but it still behaves the same.. revs clean from 2-5 thousand until about 5-15 minutes of this, then it dies.

The fuel filter was something I was also suspecting, perhaps it gets clogged, and then when it sits the junk falls back to the bottom, but embarrasingly enough, I can't find it!

[ARCHINSTL]

Look below the brake booster, on the DS fender, just above the frame rail. It's a white/translucent plastic canister about 3+" high and about 2+" in diameter with two rubber hoses going in the top. It's easy to replace - just be careful rotating the hoses - they can get kinda "welded" to the canister.
Most parts stores keep this in stock. Heck - I just got a notice that Advance Auto is open today!
Tom M.

[red91sit]

I will give that a check ASAP.. I'm blizzarded away from my poor tercel right now... sniffles...