1994 Toyota Tercel Engine dies while slowing down then hard

Start by checking the fuel pump relay.

Look at diagnostic port, short Fp and B+, if engine runs, then relay is bad.

I have to drive 100 miles to work on this today. So when I get there we'll try.

Well I did as requested and it started but it did start at times so this may or may not be the solution. So what we did was swapped out two identical relays. We then drove it for about 1/2 hour around his neighborhood w/o a problem. So we are going to hope that this fixes the problem. I will get back if there's an issue or w/i a week.

Has been a very difficult problem. :)

Good news, let us know.

Well my son didn't drive it for a couple of days then it starting acting up again. Same hard or no starting.

Just to let you know what we have changed.
Fuel Pump - new
Fuel regulator - new
All new vacuum lines
New coolant temp sensor.
Fuel pump relay
Tune up - cap, rotor, wire, plugs.

Replaced with used.

TPS The original did test ok - grasping at straws here.
The vacuum switches attached to fuel regulator.
The IAC was removed and cleaned.

Tested -

All the sensors and switches that had test procedures in the Haynes manual we tested.
Coil - test right exactly as in the book.
TPS - tested fine through the whole range.

It will start when cold, and when it hot, but when it sits for a little after getting to op temp it either is hard to start or won't start until it's really cold. We do smell gas at that point.

We are really stumped.

Try a used ignitor.

We have a couple sitting around so we'll give that a try. I have another (Tercel - 92) that had similar issues so I grabbed a bunch of parts from several junked cars at our local pick and pull.

I think we have changed every part under the hood except that - probably should hve.

I'll let you know.

Let us know.

Ok I think we are getting close. We changed the igniter w/o making a difference - we get good spark both when it starts and when it does not..

We can reproduce the problem.

Start the car when cold - standing an hour or so.

Run it for a period of time - two - three minutes.

Try starting after about 5 minutes - will not start. Strong smell of gas - pull plugs and they are wet. If we try right after stopping it will start.

Wait a couple of hours and it starts.

We are going to change the Fuel pressure regulator even though it's new.

We have tested the switch to the regulator and it works according to the book.

It appears that the fuel pressure remains and the fuel is leaking into the cylinders so when it tries to start it's flooded. Is there something that should be releasing the pressure when the car is shut off?

Fuel pressure regulator.

Remove vacuum line to it and check for gasoline, if present, then FPR is ruptured.

Well we switched the FPR - had a new one and 2 used ones - same symptoms.

I had him remove the gas cap (new) and try to make it fail - it would not fail. He then put the cap back on and it started - let it run for a minute - then waited 5 minutes - it would not start.

I'm sure it fuel related just not sure which component is causing the problem. We did swap out the injectors - same thing.

I guess he could ride w/o the gas cap. :) When we swapped the injectors we damaged one of the O rings so I have to get a new one - That'll have to be tomorrow.

I really think we are getting close.

You may have to remove tank and check the return and vent lines, they may be clogged.

I believe great minds think alike. I was thinking yesterday that I was going to go under the car a trace the lines and see if something had hit one of them. I should be able to check them w/o removing the tank. The car is easy to access the connections to the tank and the engine. I was going to remove the connections and blow air through them. Of course it was raining this morning. I'm hoping for clearer skies this afternoon. Not enough room in the garage to move a car into it so I work outside. I have a wood working shop - priorities you know. I'll let you know.

Hope you find the problem.

I disconnected the vent lines and was able to blow air (low volume) through it w/o a problem. I drove it around while the gas cap was off and it started every time. Then I let my wife drive it to her school where it sat for about 1/2 hour - wouldn't start. I was able to get it started - 15 minutes later - by pressing on the gas petal when attempting to start - it did - not first try - second. She drove it home. It has lots of spunk when it does go. I'm at a loss. I also was able to blow air through the charcoal canister.

I'm going to sleep on this again. I need to jump in the pool.

Was gas cap off when it did not start?

Well it doesn't start with cap on of off.

Just to recap where we are.

It will start when sitting an hour or so and over night. It will also start if I just shut it off and try to start it. I won't or is hard to start if I run the car, shut it off, and try again about 15 minutes later. I have been able to start it each time now but it doesn't want to and it idles only if I give it gas.

Will a bad IAC valve cause these issues? I did take it off and cleaned it really well - it did improve a lot - no more stalling. I replaced it with another used one and the problem got worse. So I'm thinking that the IAC could be the cause.

I'm thinking about ordering a new one and just try it. I know they are expensive (got a line on a 1/2 price new one) but that would eliminate another possibility.

IAC can cause stalling, if it moves too far it will cut air off to engine.

I've been gone for a couple of weeks so no update. I should be getting a new IAC soon. I'll keep you updated.

John

Fixed!!!

I got a new IAC (good price on the internet). Cleaned the throttle body, and new vacuum lines. My wife has driven it now for 2 days for all her short trips and had no problems. It runs great. Burning a little oil but that was like that before.

Thanks for the help and hope that others that have this problem can use this info. One thing we (son and I) read was that the IAC should be cleaned on a regular basis (40k miles I believe) - I would doubt it this one ever was. I think this was was having problems opening and closing properly. It was very clean so that wasn't the issue. I tried to take it apart to inspect it but it wouldn't let me.

My daughter drives a 92 so when she get home later this month I'll be cleaning it's IAC.

There is no set maint. interval on the IAC, I have a 1991 Corolla with original IAC.