wawa92gxe

iTrader: (1)

t has been running very nicely, but today the car was running like POS. It stumbles and shakes very badly when accelerating from stop, like it is going to choke or die. I have checked the self-diagnosis and pulled code 55. Mode I also fine. I was suspecting a MAF error, but couldn't pull out any error code.
I have done tune up recently. all spark plugs, distributor cap and rotor. timing belt etc. The fuel filter was replaced three months ago, and it has about 5000 miles.
I have cleaned and checked the TPS and it seemed fine to me. All measurements were good.
I have looked into vaccum lines and couldn't find anything obviously wrong.
The car once in a while today did turn back into normal running condition, but that would only last for a few mins and went back to POS again.
Sorry for the long post.
Any suggestions would be greatly appreciated.
Thanks in advance.
Denga

Greeny

iTrader: (43)

Unplug the maf sensor and drive it around for a while....This will eliminate the maf from being the problem....

Side note: the engine will not rev over 2000rpm while the maf is unplugged...But if it is the source of your problem, it will run smooth within that rpm range..

wawa92gxe

iTrader: (1)

Just replaced fuel filter this morning and it is running well again.
I hope this is the only culprit.
I guess the fuel in the tank is POS and clogged the filter??
I will report back if the problem comes back again.
Thanks.

92 Max

When I had my problem with vacuum hoses it wasn't evident they were bad until I pulled it off and tried to pull it off and push it onto a tapered connector. Then it split easily and, upon closer inspection, I saw small splits in the end that weren't visible when it was on. It seems to me that this started happening after I cleaned the throttle plate area. Perhaps some gunk and cleaner got down the ports at the bottom of that area and down into these vacuum hoses.
Also, with the cold WA weather recently, have you checked out ice in the fuel line? Throw in a couple bottles of heat into a full tank and see it this helps after it works through the system

valz23

iTrader: (1)

I had a problem kind of like this on my old VG, couldn't figure it out for a while, it would come and go. It was as simple as the bad spark plug wire, you mentioned changing everything, but them when you did the tune up. Even if it's not the problem, would recommend changing them, as a part of the tune up.

todamax

iTrader: (6)

Um, when I unplug the MAF from my car it dies.

*off to do some searching*

alpicone

It sound like a fuel injector related problem. Listen to the exhuast coming out of the muffler to see if you hear a put put put sound indicating a miss in the engine. Then figure out which cylinder is missing by removing the spark plug wire one at a time and looking to see if there is a difference in the engine. when you get to the one that makes no change when disconnect the wire, then you found the cylinder with the miss. Check the wire connecting to the fuel injector. On my car there was some green corrosion stuff causing the problem. I cleaned it with electrical cleaner and a wire brush and then the problem was solved.

wawa92gxe

iTrader: (1)

The tune up (everything except fuel filter) was done two weeks ago.
So far the car has not shown any sign of going back to what it was two days ago.
I have dumped a can of seafoam in the tank besides the new fuel filter.
I think Costco's gas is what i have to spit on.
I will replace all vacuum line anyway, just for added reliability.
Thanks for all the advices, folks.
Denga

wawa92gxe

iTrader: (1)

Well, the problem came back this morning after two weeks. Basically, i can't accellerate.
There was no response with gas pedal pushed. The car can only run at 10-15 mph and shaked like it 's gonna choke to death.
I added a bottle of STP superconcentrated fuel injector cleaner several days ago.
Could it be the junk in the gas tank be stired up by the detergent and clogged the fuel filter again?
Any other ideas?
Thanks in advance.
Denga

alextothestars

could be likely;when my car did that, i noticed the exhaust fumes were very black/carbon and smelled like something on fire...it dirtied up the engine bay and bottom of the car pretty bad.

i changed my oil and it went away a few minutes later. seems that when my car was burning oil, it deposited and since ive got a lot more airflow now, its getting "stirred" up and is causing it to run like it did when it was burning oil...which was ****ty and wouldnt let me down shift with the pedal fully depressed.

i use 93 octane and my ecu i supposedly set to run 12:1 compression ratio. its definitely using more gas because ive noticed a dramatic change in gas usage since i swapped my stock for the, as the ebay seller said, "professionally socketed" ecu.
well find out this spring when i get on the dyno, eh?

just letting everyone know the specs and see if theres anything in common between our setups that could be causing this.

falseicon

iTrader: (2)

Could be injector related, though when 2 injectors (and the Fuel Pressure Regulator) went on my car it would still accel somewhat normally but die when at a standstill; not quite the same symptoms. What does it idle like?

4dscPat

I know it sounds very obvious, but make SURE your spark plug wires are installed in the correct order. I once spent two days tracking down a similar problem and it turned out that I had swapped two of the wires.

dchjort

My problem was about the same I did a tune up it helped a little then I changed all 6 injectors and it runs like a champ . Also cleaned IACV and TB, replaced vacume lines