Running Rough - Toyota Nation Forum : Toyota Car and Truck Forums

DoDo1975 · 07-07-2005, 02:10 AM

Lately I have been having some weird problems with my 1988 Corolla GTS. The problems seem to be fuel/ignition related as stated below.

Engine idles erratically - Very Occassional stalling when stopped.

Car seems to run perfectly when under slight acceleration.
Under heavy acceleration car sometimes seems to stop receiving fuel momentarily and jump.

When under load (uphill) and constant mid-rpms though not accelerating car sometimes seems to miss. This happens maybe 20 times on a 500 km trip when there was just a little slip.

Car seems to run rough when driving in gear but not accelerating.

I have had a read of some of the forums and found similar problems (usually just while idling) and have heard possibly PVC valve, EGR, spark plug wires, fuel filter.

I have replaced my plugs, air filter and fuel filter. As the car is old, I can't really spend alot of money on it, especially when it seems most of the time mechanics dont actually fix these types of problems. What is the most probably cause for these problems, and what might I be able to fix myself without spending a fortune. I have decent mechanical skills, but am by no means a mechanic. Other than this problem, I love the car.

Thanks for any help,

Joel
Kelowna, Canada

karazy · 07-07-2005, 03:57 AM

It could one of many things, some that you have already listed. It's always best to start with the easy (read cheap) stuff first and work your way through, until it works. Do a leak check on the plug wires and check the cap and rotor. Check all the vacuum lines for cracks/signs of leaking. Test the EGR valve. Depending on how old the timing belt is, it may be time to change, or atleast, check the timing. Hope this helps.

saiklon · 07-07-2005, 05:06 AM

I had a similar problem with my car. It had to do with wrong timing. Have someone check your distributor thoroughly. Make sure it's the right one for the engine and that the cylinder firing order is ok. My 4A-GE can run with more than one firing order but won't work right with some.

In my case the idle problems would reduce if the engine was severely retarded, of course the power output then would be totally pathetic. The engine would also detonate at the slightest opportunity.

***REN69*** · 07-07-2005, 06:18 AM

The fuel pump could be at fault too, maybe its pulsating fuel rather delivering it in streams I'd get that checked. I also hope you used OEM wires, don't use the crappy aftermarket ones because they're not as good as the Sumitomos. Adjust your idle screw too, make it a little higher so that the motor runs around 800-1000 at normal idle; the idle is probably way too low and that's why it stalls when stopped.

My cars are old, but I spend the money on them because I love them and need them for getting to work. My 89 GTS was basically my highway cruiser for the last 4 years, I put 135,000km on since I bought it with 211,000 and its never let me down. Now with the 90 GTS in my posession with 143,000km, lets just say someone is gonna get spoiled.

DoDo1975 · 07-07-2005, 11:30 PM

I had a little trouble finding the PCV valve. Actually I was unable to locate it. I have seen posts saying it doesnt even exist on my engine, which is the 4GAE I think, the one for the 88 GTS. my haynes repair book says its there however. Anyone know for sure.

Also, anyone know how I can check my EGR valve, that will be the next thing I test. I do indeed have OEM wires. The engine also already runs around 800 - 900 RPMs whens its idling nicely, so adjusting it wont make much difference

Thanks