1998 xls stalls when accelerating - Toyota Tundra Forums : Tundra Solutions Forum

sea1skiff · #1 (**permalink**) 07-04-2007, 11:59 AM

I have had my car in the shop for over a week now. I initially felt as though i had bad fuel injectors in that she would stall out anytime I tried to accelerate at a moderate to high rate.

My mechanic and I have been trading services with each other over the last year (bad move) and he says it is not the injectors and initially thought it was the coils but seems to now think it is the computer itself. I really dont know what he means by the entire computer but he has been trying to find one used to save me some money.

He indicates a new one will run 1600 or so.

Can anyone explain the concept of the "entire computer" and do you know where I could price one to check and see if he is getting the best price available.

btw - 1998 avalon gold xls, 172k miles, still runs like a champ and I feel I can get another 50-75k out of her so I am not willing to abandon ship yet

Thoughts and opinions appreciated

mustang67408 · #2 (**permalink**) 07-04-2007, 12:16 PM

Is the check engine light on?
Any CODES stored?
Fuel pressure?
1998 Avalons are know for bad coils (see TSB attachment) this will cause a hesitation or stall also, if 1 or more are bad.

An entire ECU, I highly doubt it. Unless it got wet or the vehicle was jump started backwards.
The ECU is the brains of the entire vehicle. It tells the car how and when to run, depending on the various sensor inputs.

Stalls on acceleration, sounds like a DIRTY or BAD MAF sensor.
The MAF sensor tells the ECU how much and how fast air is entering the engine, so the ECU knows how much fuel to add to the engine as a base line guide, other sensors fine tune this fuel trim.

An overly sensitive EGR position sensor, could also make the vehicle stall under moderate acceleration. This sensor allows EXHAUST GAS into the engine intake to diminish or cool combustion chamber temperatures reducing harmful emmisions (NOx), too much EGR and the vehicle stalls or bogs down.

$1600 for an ECU is a rip off. I think I can get it alot cheaper from Toyota than that, if thats what it needs. PM me for details on this.

You can check the MAF and clean it yourself (see attachments)

We need to know the answers to the questions above to help you diag this vehicle accross the NET.

When was the timing belt checked or replaced last?

Thanks

sea1skiff · #3 (**permalink**) 07-04-2007, 12:42 PM

The check engine light is on, Mechanic says he has checked some things based on the codes (not sure exactly what that means) and that lead him to the bad coils, changed those and still had hesitation and what he termed conflicting information from the codes. I think he wants to try the ECU to see if that solves the problem.

Mustang check your PM

csaxon · #4 (**permalink**) 07-04-2007, 04:56 PM

Get Your Wallet And Run Away From That "Mechanic"!!

sea1skiff · #5 (**permalink**) 07-10-2007, 11:05 AM

Went by the shop yesterday afternoon with Mustang's recomendations. I could tell the mechanic was a little peeved that I had done the research, anyway, he had replaced two coils which he said were difficult to diagnose as being bad which had solved the hesitation problem. I drove it and in fact it ran like a charm. He then indicated the catalytic converter was bad and would need replacing before the next inspection date. Does anyone have a feel on a fair cost to do that? and also - the car has had a slight "rumbling" sound as it shifts gears around 20-30 mph - the sound actually feels as though it could be located in the exhaust system, could this be the catalytic converter going bad?

Thanks

mustang67408 · #6 (**permalink**) 07-10-2007, 12:01 PM

Quote:

Originally Posted by sea1skiff

Went by the shop yesterday afternoon with Mustang's recomendations. I could tell the mechanic was a little peeved that I had done the research, anyway, he had replaced two coils which he said were difficult to diagnose as being bad which had solved the hesitation problem. I drove it and in fact it ran like a charm. He then indicated the catalytic converter was bad and would need replacing before the next inspection date. Does anyone have a feel on a fair cost to do that? and also - the car has had a slight "rumbling" sound as it shifts gears around 20-30 mph - the sound actually feels as though it could be located in the exhaust system, could this be the catalytic converter going bad?

Thanks

How did he know CAT was bad?? CODE? GUESS? Not sure if I trust this guy, he wanted to sell you and ECU

.
Which CAT CONVERTER? There are 3
The front one (nearest radiator) usually makes that rumbling sound. Sometimes people confuse it with a rod knock it gets so loud.

sea1skiff · #7 (**permalink**) 07-10-2007, 02:40 PM

The check engine light had been on and was off yesterday. He indicated it would come back on shortly due to the converter malfunction. He did say that if I wanted to wait on that I could in that the car is not due for inspection until end of September. That statement lead me to think he was on the up and up about the converter.

mustang67408 · #8 (**permalink**) 07-10-2007, 02:50 PM

Quote:

Originally Posted by sea1skiff

The check engine light had been on and was off yesterday. He indicated it would come back on shortly due to the converter malfunction. He did say that if I wanted to wait on that I could in that the car is not due for inspection until end of September. That statement lead me to think he was on the up and up about the converter.

Oh ok. I didnt know the engine light was on still. DId he give you a code?
He probably is right then

There is a cat built into each exh manifold and then there is 1 in the header pipe. There is no exacting way to tell which is bad, you have to usually change all 3. I do not recommend aftermarket cats, they usually do not work or last. Thats why they are so much cheaper.
Glad you hesitation is gone.