94 Tercel Idle Stall problem

[planetes]

I've got a 94 Tercel with about 154K miles on it and it has been idling very rough and stalling the past couple days. A little background about the car: My wife has had it since at least 98 and it ran well for us for several years. We bought a new honda civic in 2006 and drove that as the primary car while the tercel just sat in storage. About a month ago the civic was totalled and I'm forced to fall back on the Tercel until the insurance gets straightened out and I can buy a new car. In summary, it sat un-driven for the majority of 3 years.

I recently had it worked on to get the seals and head gasket replaced and I suspect that a lot of the carbon and crap that had accumulated in the car has start breaking lose and is now working its way out. The mechanic also said that there sounds like a crack exists in the exhaust manifold. The timing belt was replaced in this process.

I have ordered a haynes manual and a toyota repair manual but until those arrive I'm looking for some help diagnosing the idle problem.

I have NOT begun taking apart anything since I don't have the manuals yet and I'm nervous about blindly disassembling without some diagrams.

The things I've gathered from exploring the web that could be related:

The PCV valve
The EGR valve
The IAC valve (I'm not sure if this applies to a stall while idling).
Fuel Filter (possible)

Anybody have any suggestions on where to start? I wouldn't be surprised at all if the valves are clogged/bad but I want to

I'd like to start doing the work myself if it's feasible.

[96paseo]

Cleaning the IAC is the first and cheapest thing you should try. Some Seafoam Deep Creep, an old toothbrush and some time is all you need. Its very easy to do. If that doesn't do it, check the condition of your ignition related parts(cap, rotor, plugs) to be specific. After sitting for three years, see if some furry friends have made a nest on top of your valve cover and chewed your spark plug wires. The little bastards have done it twice to my paseo over the years. Its possible to be the fuel filter and its good maintenance to replace it(especially if its original). Service interval is 50k miles but they will last a lot longer than that. Filter is easy to get at. Recommend the use of lines wrenches for the fittings. Good luck.

[planetes]

Interesting.. thanks for the info. I don't know if it helps but I am NOT getting an engine light while driving or anything.

My suspicion is this:

I have a cracked exhaust manifold which at idle is allowing enough oxygen to enter the exhaust (at idle there's not enough exhaust pressure to prevent it) which the oxygen sensor is detecting and it's causing the car to over compensate thinking it's a lean mixture.

So, i'm going to go prowl around a couple salvage yards on wednesday (one of my days off) and see if I can't find a "new" exhaust manifold in good condition. If I do, I'll replace mine and install a new oxygen sensor (since I'll have the damn thing out anyway). I'm also swapping the PVC valve since that's a very simple and cheap fix.

I'll start with the problems I know exist and then move on to cleaning out the EGR and IAC valves. I'm a bit cash and time strapped (work full time as an engineer) so that seems like a reasonable plan to start hunting down the problem.

If anyone has good suggestions for finding a manifold in the Seattle area I'd appreciate the tips.

[96paseo]

Try www.car-part.com Very good site that is a network of junkyard listings. If you can't find one in your area you can call the yard and see if they can ship it to you.

[3ee4banger]

Originally Posted by planetes

Interesting.. thanks for the info. I don't know if it helps but I am NOT getting an engine light while driving or anything.

My suspicion is this:

I have a cracked exhaust manifold which at idle is allowing enough oxygen to enter the exhaust (at idle there's not enough exhaust pressure to prevent it) which the oxygen sensor is detecting and it's causing the car to over compensate thinking it's a lean mixture.

So, i'm going to go prowl around a couple salvage yards on wednesday (one of my days off) and see if I can't find a "new" exhaust manifold in good condition. If I do, I'll replace mine and install a new oxygen sensor (since I'll have the damn thing out anyway). I'm also swapping the PVC valve since that's a very simple and cheap fix.

I'll start with the problems I know exist and then move on to cleaning out the EGR and IAC valves. I'm a bit cash and time strapped (work full time as an engineer) so that seems like a reasonable plan to start hunting down the problem.

If anyone has good suggestions for finding a manifold in the Seattle area I'd appreciate the tips.

If you think thats your problem just unplug the oxygen sensor for now and your computer will run the car in an open loop mode your engine light will come on but that would work

[shortlid]

Would a O2 really cause stalling at idle??

[kinako]

Originally Posted by 96paseo

Cleaning the IAC is the first and cheapest thing you should try....Good luck.

+1. Cleaning my Paseo's Idle Air Control Valve as 96paseo posts here, solved a great majority of my idle quality and consequently a charging problem I had; the only deviation from his instructions, was I used carb cleaner in the hole for the IACV in the TB, and let it sit a few minutes. It's something I plan to do about twice a year.

Using Seafoam fuel system cleaner is the first thing I recommend to anyone in the motorcycle tech industry I came from, who has a few years on their machine and driveability problems that don't point to any specific component. I still run a maintenance dose.

Also +1 on rodents -- I've found them in motorcycles atop the air cleaner, nesting in the exhaust can, fried to a crisp behind the headers, even sh*tting on the valve cover, wire insulation debris all over.

Oh, btw... love the username, planetes. Have the graphic novel and DVD series.

[shortlid]

Thanks, ya Seafoam rocks! Used it and MMO for years. Does the '97 Tercel have a fuel filter that could be clogged??