Help with a 91 Corolla please

[Charlz B.]

Hello all. Newb here...working on a 91 Corolla DX with a 5 spd for some friends. Problem is described as "runs rough early in the day; smooths out as day goes on." I've been driving the car for about a day now and this seems accurate; this morning the car would miss intermittently and backfired once. Yesterday (at 3pm) the car seemed to be running well (after replacing the 2 quarts of oil it was missing). My initial thought is this is a fuel delivery problem, so I'm going to change the filter but I would like to hear anyone's experiences or insights into the matter. Thank you kindly in advance!

[FinalGear]

Do the stuff you know first!
Example:
Check the Oil
Check the Spark Plug
Check the Spark Wire
Check the Distributor Cap
Check the Ignition rotor
Check the transmission fluid
Check the Battery (Test)
Check the alternator (Test)

Look for wear and tear!!!

If its the fuel pump....those things are $$$$!! But are fairly simple to install

[Charlz B.]

Ok, another question. This car being manual and all, now it has an intermittent starting problem. Apparently, sometimes it will turn over and sometimes it will not. I'm thinking the ignition wiring/switch? Perhaps the wiring tying the clutch to the ignition and starter?

Any insight on how to test the system with a test light or DMM?

Thanks,
Charles

[blb]

How many miles on it?

[Charlz B.]

99150 mi approximately.

Edit - I figured out the rough running problem that began this thread; traced it to a faulty CTS.

[blb]

For the second problem, I would suspect a faulty starter or poor battery connection before I would suspect an ignition switch problem. Check for voltage at the small wire at the starter when the key is in the "start" poisiton. If you have voltage, the starter is faulty. If you don't, the lockout switch on the clutch may be the problem. You can temporarily jumper around the switch for testing purposes.

[90 GP]

Intermittent no start is probably the starter solenoid contacts being worn down. They can easily and cheaply be replaced.

[tashirosgt]

Next time it won't crank, try connecting the negative battery terminal to the block with a jumper cable. If that fixes it, the problem is a bad ground. That's the problem I had on my 1990.

[Donald]

To determine if it is the switch or switch wiring, when it won't start, turn the ignition on, and run a jumper wire directly from the starter solenoid input treminal (very hard to get to) to the positive pole on the battery. If it starts, then you have a start switch/wiring problem.

I have the same problem with my Camry right now.

[Charlz B.]

Ok, so the clutch switch, starter relay, and wiring all checked good. Put in a new starter and off she went!

Now, in respect to the CTS...am I wrong in thinking that it is the large sensor in the front of the water jacket with the contoured electrical plug and 3/4" hex? If I am wrong, can someone please tell me what that sensor is? I went to Advance and NAPA to try to get a CTS, and both times I was given a similar sensor with the same electrical connection, but with a much thinner body and treads, and a shorter probe.

[jdonline]

I had a problem with a saturn that didn't turn over on the first crank either. It stemmed from a poor initial combination of air and fuel. I ended up not repairing it because it would cost $300 and it wasn't damaging the car. Hopefully it something like that for you.

JD

[Charlz B.]

No one on ID'ing the mystery sensor?