Hi,

I got a 1998 Toyota Tacoma. Idling the truck runs fine. Under acceleration it backfires, misses, and shakes...then the check engine light comes on and flashes( it doesnt stay lit)

After the truck comes back to idle. The light goes off and it idles fine.

No spark plug or wire problems.

Help!

 

well i took it to the dealer

 

What did the dealer say? BTW Are they trying to throw you over the barrell?

 

they are taking their sweet time on it. I'll let you know soon as I find out.

 

blinking MIL is an engine misfire

no other problem makes it blink. easy to tell
a misfire this way. a misfire is the worst possible
problem that the ecu can have and still make the engine run,
... it blinks because running like this destroys your engine
starting at the cats, then on to more things over time

 

likely the same problem really... how do you fix an engine misfire if it is not the plugs or wires?

Thanks tons!

 

what ever came about your problem. My 04 started doing it today.

 

I would really like to know what this one was caused by because mine is probably headed there

seriously folks

I drive a LOT of miles like 50,000 a year
I turn over a lot of trucks get em at over a hundred and let them go when repair starts to get too cost restrictive
this is my third Toyota and every time I say never again

most trouble I have ever had with my high mileage experience is with the toyotas

compared to ford/chevy/dodge

very painful parts system

not especially easy to work on or diagnose

throws up the most bizarre problems

extremly difficult to find diagnostic help without dropping it off at a dealer

is it just me ?

 

MAF, PCV, EGR, TPS, vacuum, fuel filter, injector
try this:
http://www.los-gatos.ca.us/davidbu/toyota.html

 

that was a great writup on diagnosis . I just did exactly that same routine to cure my rough idle and stalling when cold at stops except that I changed the plug wires and plugs and valve cover seals and removed and thouroughly cleaned the IAC and throttle body, but I have not yet changed the fuel filter (which rarely if ever makes a difference)

my #4 plug wire cap was submerged in oil from bad plug tube seals but no misfire and no change after fixing
the dissapointment is that after all that my cold stalling is still there


If I had a misfire I would look at the coil packs plug wires and plugs

 

I have learned that if I check sensors, vacuum, fuel, electricity, etc. and the problem is still there, I look at the PCM. New PCM's are hateful prices. You could buy a new used vehicle for that price. I am sorry to hear that you still have a misfire. Do you have access to a scanner? If not, do you have a community college near you that has an automotive course. You can save a lot of money by taking it to a college for students to diagnose. My school charges a flat $25 for diagnosis and when problem is found you have the option to fix it or we fix it and you pay for parts.

If a misfire is not found on a prelim. scan then your vehicle may have to go through a global trip to figure out the root cause. I suggest a scan tool.

P.S. dealer will suck you dry in money and time.

 

Hey there, I have a similar problem in my 2001 4Runner 3.4L 4X4. I was on my way back from hunting yesterday, and the truck started sputtering, and the check eng. light flashed then stayed on. It's repeated this several times on the drive home, and this morning. Took it to my Cost Less Auto here, and they checked my codes for free. P0300, P0303, P0305 and P0306. I've searched around on some forums and am looking for any more help anyone can give. The truck is running very rough, and sucking gas like a HOGG!!!

 

am starting to think that the only solution is to get a ford or chevy which are fixable
every toyota I have ever had is an unrepairable nightmare can of worms

I have replaced almost every performance related sensor and electronic part under the hood , checked fuel pressure, taken it to the dealer for a $100 "maybe it this or that drop it off for a few days and bring us lots of money" diagnosis
and it still runs like a turd

to add insult to injury the toyota parts prices are cruel and obscene

I am on the precipice of attempting to dump this pile

 

ToyotaTolan--- P0300 is a random multiple misfire code. Where and when did you fill your fuel tank last? Before you start tossing plugs, wires, injectors and ECUs take a fuel sample. The main line is located near the driver's side fire wall. You"ll see a hard line coming from the bottom of the truck to a big black cover to the rubber line. Remove the black cover and you'll see the connection. Push the 2 yellow release clips and pull. Wear safety glasses cuz that line is pressurized. Attach a hose to the hard lane and run it into a clear, CLEAN bottle. Cycle the key to activate the fuel pump. Water will separate from the fuel. If its E85 it will have a slight blueish tint. Does it smell like fuel?

Blinking check engine light usually means the cat's temp is extremely hot.

 

thanks for the heads up, but the wires/plugs seemed to be the issue. The plugs that I pulled were very chafed, and had lots of carbon, but the real issue was the wires. The boot going to cylinder 6 was cracked 3/4ths of the way around (causing some serious arcing, I'm sure), and the others were flaking and corroded on the inside. After completing the tune up, the engine stopped running rough and the power is GREAT (after a brief issue with a vacuum line not being hooked back up...by me , but the gas mileage is still very bad. I only had a quarter of a tank in it when I finished with the repair, and I know the guage can float a bit when the tank is that empty, so I'll be filling the tank and adding an injector cleaner this week to see where I'm at.

Any ideas on what could be killing my mileage?

 

Glad you got that squared away!

Gas mileage? Theres a lot of factors.... How many miles? Stock tire size? Give it this tank of gas till you decide your mileage issue. Could have suffered with the plug wires. If you're going to do an injector cleaner spend a little cash and go to the stealership. The cleaner goes straight to the fuel rail and not the gas tank. The fuel line is bypassed and its straight cleaner into the injectors.

 

Sorry, I should have prefaced this: I'm fairly savvy with vehicles, no mechanic, mind you, but I can find my way around an engine bay. Couple that with a penchant for technology, and the internet and I get along famously. That said, a while before my misfire issue made itself apparent, I stuck a can of SeaFoam in a full tank of gas. My 2001 Runner has 235K on it, about 20k on brakes and factory size Bridgestone Dueler AT (m+s). Before the SeaFoam, I was getting around 12/17mpg--city/hwy--after using it, my mpg shot up to around 16/22 (measured through several tanks of gas). Very soon after using it, I was passing a slow vehicle while going up a significant incline, and the engine backfired. It began to run a bit rough immediately after. Two months and a couple thousand miles later, on the SAME HILL, my misfire issue occurred. I thought it was odd that I happened to use arco gas on this last trip for a half tank, since I had decided to never buy gas from them ever again. Oh, and after going only 30 miles on a quarter of a tank, I'm positive that something else is wrong...timing, maybe??? Did disconnecting my neg on my batt for 45 min screw with my efi??? No leaks that I can see/smell under the hood, or on the ground, exhaust does not smell rich anymore.

 

When did you disconnect the battery? When you replace the ECU OR have the battery unplugged for a long period of time you need to do an idle relearn. I turn off any load and start the car. I'll let it idle for at least 10 minutes. BUT I dont think that would cause bad mileage. If it was out of time by a tooth then it would run really bad and the CEL would turn on. I think its worth checking though.

So after the tune up it ran great but only got 30 miles on a 1/4 tank?

 

You should never ever just throw parts at something and hope it fixes it. Any real qualified shop can diagnose just about anything. Its all a mater of elimination.
The best thing to do is get a quality scanner that can show live data and use that in your diagnosing. Is the problem in open loop/ closed loop. What is the engine load, where is the ignition timing, what rpm. Live data can tell you lots, and a high end scanner will even record data so you can see when the problems occured.

 

I had the same type of problem yesterday with my 98 Taco with a 2.7L 4-cyl. Except mine added the kicker of white smoke rolling out the exhaust.... Initial response is head gasket??? Popped the radiator cap, and couldn't see any coolant at all. Passenger side of the block is leaking something, even though it didn't look like coolant, may havebeen a combo of coolant and grime... Going to pull codes today.