Our 98 Corolla has recently become hard to start. Usually two or three starting attempts for a few seconds before starts and then idles roughly for a few seconds, then drives fine like it always has. Has 51k miles, oil changed regularly, 100k-mile tuneup/spark plug replacement not yet reached (maybe another 18 years, in 2034? Anyway, has performed great always until recently no longer starts immediately. Replaced battery, no change. Have BlueTooth OBD scan tool connects to Android phone - cool display, no codes, what to check, do next? Love this car!
A 98 model with that few miles on it is probably “bunged up”. Others here will likely recommend Seafoam and some vigorous cross country driving to blow out the cobwebs.
I would definitely have an ignition "tune up’, replacing the plugs and checking all the wiring. The fuel delivery system also likely needs purging.
Just changing oil and filter is not complete maintenance. Your owner’s manual will likely also have TIME BASED intervals for maintenance.
On a vehicle this age there are a lot of possibilities… and combinations of possibilities.
As Doc suggested, a good tuneup has solved many a start problem.
If that didn’t work, I’d want to do a compression test to evaluate the condition of the engine. When engines get old, not only do the cylinders and rings wear, but also the spring tension in the rings relaxes and they don’t hold compression as well. They can also get gummed up with combustion byproducts.
Additionally, you’ll want to check the battery cables and the cable ends for any signs of corrosion. Corroded connections have resistance, and that “drops” the voltage available to the starter.
Great - thanks!
I’ll do the compression test first, and check what I can, like cables. If the compression is ok, I’ll replace what I can, and arrange a tune-up with the dealer, whose mechanics have always done an excellent job. Can’t afford much these days.
If you can’t afford much . . . you should stop going to the dealer
They will have the highest labor rates and parts prices
A decent independent shop . . . NOT a big-name chain . . . would serve you just as well
Try leaving the key in the on position for 10 seconds before attempting to start, if that helps then fuel pump is bad.
I want to repeat Docnick’s warning. On a car that accumulates few miles as this one does, maintenance intervals would be time based, not mileage.
I suspect the tuneup is way overdue. I suspect there is a 10 year limit, and you are almost ready for the second tuneup.
Are you changing the oil every 6 months?
don’t forget to change the fuel filter, cheap and easy to do.
I have a slightly earlier version, early 90’s, of the Corolla. Based on my own experience, if I had that problem first thing I’d do is check the intake manifold vacuum at idle. And the ignition timing. And idle rpm. If any of those wasn’t to spec, I’d ask my shop for advice. Intake manifold vacuum out of spec probably means a cat back pressure test. Ignition timing or idle rpm out of spec could mean a number of things. But if that all tested ok, I’d next do a simple routine maintenance job to bring it all up to the manufacturer’s recommendation for time and miles, replace the plugs, fuel filter, pcv valve, fuel filter, distributor cap, spark plugs wires, ignition rotor, and engine air filter. If the coolant was due, I’d change that out too for good measure… Still a problem, next up would be a fuel pressure test. The throttle body may need to be cleaned too. And the EGR valve could be sticking.
If you are going to remove the spark plugs for a compression test you should install new ones, the is no point in installing the old one then paying to have them replace during a “tune-up”.
It is unlikely that the longer than normal crank time is due to low compression. Focus on the fuel system, check for fuel pressure drop after the engine is shut off.
I’ve seen it a few times where long cranking times WERE due to low compression
And low compression was due to incorrect valve lash
Note . . . that was on cars with adjustable valves
I don’t know if OP’s Corolla has adjustable valves or hydrualic
Concur w/you @db4690 a compression check makes good sense. And easy enough to do. But I’d not suspect that as the most likely cause of this symptom, simply b/c of the low mileage on this vehicle.
“two or three starting attempts for a few seconds before starts and then idles roughly for a few seconds, then drives fine like it always has”
But on those cars I mentioned . . . the symptoms were the same
Could be. But my truck had those exact symptoms a few months ago, & the cause turned out to be the power valve in the carb was leaking fuel into the intake manifold causing it to flood. It would take forever to crank and start, but when it did it ran fine.
OP might try holding the accelerator pedal all the way to the floor, see if that helps. If so, could be a leaking fuel injector, causing a similar to problem to what I had w/my truck. A fuel pressure test would confirm this, as mentioned by @Nevada_545 above.
I actually like Barky’s suggestion. On my '89 Toyota pickup the fuel pressure began disappearing while parked overnight and I had to start holding the key in the ON position for three or four seconds before turning it to START to allow the system to pressurize or I’d exhibit the same symptoms as the OP. In my case, I just built the protocol into my morning starting procedure. The pickup already had about 300,000 miles on it at that point.
I tried the 10 second (and more) with key on but not started. It did not make a difference.
I replaced the plugs and wires. The original plugs look fine - hard to believe they are 18 yrs old. Anyway, that made no difference, but way overdue.
I did a compression test while replacing the plugs (after running the engine till warm). All 4 cylinders were between 110 and 130 - makes sense since still gets great mileage (about 25mpg in town and 33mpg on long drives).
It still takes a while to fire, and sometimes it barely starts and then runs normally at idle. I think a sensor somewhere may be confusing the computer - and that suggests the sensor is only used during start, and not once running. I have a OBD scanner, and saw online about fuel trim and vacuum. And others here mentioned EGR and PCV. So I will check those next.
When I can, I’ll have my mechanic do the fuel injector, throttle body, etc. cleaning, and check the fuel pressure. There were other suggestions - I’ll see which of them I can do, and if not have my mechanic do them.
So far, can do these myself, and no hurry. Nice to learn about all this and save some money too. My dealer mechanic has always done a great job - perhaps it is a bit more expensive than independents, but my luck with several independents was not consistent, whereas my dealer always does it right. I have worked with other dealers who never got things right. But once finding a good service, makes no sense to start looking again.
Thanks all - it is great to get so many ideas, learn things, and eventually find the culprit. These days someone has already provided a solution to problems that long ago were not easily found, and tended to require reinventing the wheel.
Those compression number look low to me. I measure between 165 and 175 on my Corolla, which is older than yours. Low compression is a common cause of stubborn cold starts, so that’s a prime suspect.
It can be difficult for a diy’er to get an accurate measurement of compression is the problem. If it turns out your compression is ok, and all the routine maintenance is up to date, stubborn starting is often a fuel delivery problem. Frequently caused b/c the fuel rail is leaking and depressurizing. The leak isn’t to outside the car usually, but either back into the gas tank through a leaky fuel pump check valve, or into one of the cylinders through a leaky fuel injector. If you see a lot of dark smoke out the tail pipe when you first start it, the latter is a suspect.