Is anyone besides me afraid that the Seafoam and water might really break something? Like a rod or valve or something?

The trick is to either suck it up slowly or pour it in slowly. If you dump the whole can of Seafoam or a whole bottle of water in, you could hydrolock the motor.

You're sucking in far more air than water. Sucking in straight water is definitely bad karma. I'm pretty sure the Seafoam itself is combustible so that shouldn't be an issue.

I just put a proportionate amount of Seafoam as compared to gas in the tank. That was one of several different uses it had according to the bottle.

I do not believe the plugs are fouled. New plugs were installed when the valve job was done.

I don't think so. The engine runs great at idle (except when it ran low on fuel once) and when driven at a steady speed. In 5th gear I do not notice this problem at all. Only when accelerating or occasionally when traveling in a lower gear does it come up.

Sorry I just now noticed this part of your post quite a while back. In neutral you can go over 4,000 - 5,000 RPM. I have not noticed this problem so much in neutral. It is not always the same RPM, but usually it is in the 4,000 - 5,000 range. Occasionally when it is really giving me problems I notice it at even 3,000. This is a major problem because this car runs at 2,900 RPM or so at 60 mph in 5th gear. Again I haven't noticed it in 5th gear, but this can be a headache when I only need 4th gear and it rountinely runs at 3k or so.



There are quite a few suggestions here. If I were a bit more mechanically inclined I would try them all out on my own, but since I am not, is there a way that I can try to eliminate them just through simple driving tests? Perhaps I am not being detailed enough in my descriptions? For clairty sake I will go ahead and list all of the ideas (that havent been disproven) below...

1. Strainer/Filtration device on the fuel pump
2. Blocked catalytic converter
3. Valve float
4. Ignition problem of some sort
5. Timing belt skipped a tooth

facts about this car:

1. DOHC with 2 brand new timing belts just recently put on
2. New sparkplugs
3. Had gas sit in it for 4+ - horrible odor when burned (all the bad gas has been used up by now though)
4. When accelerating, normally around 4,000 - 5,000 RPMs the car jerks as though it is not getting enough gas. Will not accelerate further until a higher gear is selected.
5. On extremely bad days it will do it around 3,000 RPMs (typical running rpm for this car)
6. The problem seems to be lessened by adding gas to the tank
7. The problem appears to be augmented when the car is running low on fuel.
8. Once when I ran the tank really really low (to presumably use up all the potential bad fuel) the engine idled extremely low (under 500 rpm) and kept dying on me. I had to gun it up to 4k rpm in neutral and quickly shift to 1st to get it out of the driveway. I coasted through stop signs to avoid stalling out. However after I had driven about 10 miles and warmed the engine up, it idled fine at each stop light I was forced to stop at. Since new gas has been put in, this problem has not come up again.
9. A relay switch somewhere in the ignition system (or perhaps a bad wire) has forced us to reroute the electric signal by connecting a wire to the battery and the solenoid and so the car now has a push buttom system to turn it on. It cranks perfectly fine with this arrangement
10. Brand new starter put on it

Items already tested:

1.) adding seafoam to the tank (further cleaning attempts with seafoam may be in the works)
2.) New fuel filter installed
3.) MAP sensor replaced
4.) Throttle position sensor replaced
5.) Loose wire which somehow connects to the engine block was replaced and reattached

I hope I have collected ideas together well enough. There are so many suggestions... I hope I also filled in the gaps as well. With this information, I am also hoping someone can tell me what potential problem source should be looked into first (whichever appears most likely).

Did they also replace your plug wires?

After reading your description again, if it really seems to be affected by the amount of gas in the tank, then it is likely fuel pressure related. Before the PIA of changing the fuel pump in the gas tank, I'd consider getting a fuel pressure gauge. It would tell you if your pump is working properly. If the pressure is low, you'd be running lean, and the symptoms of this would probably show up on acceleration first, that's when the ECU is trying to make the mixture richer.

Sorry, I don't know what the fuel pressure your car is supposed to be, but you should be able to find that info on the internet somewhere.

mrmad,

Thats a great idea. If he doesn't want to do it himself, just call about 8 repair shops close to home and try to get the best price. Ask: can you put a fuel pressure gauge on my car and tell me where the pressure sits during acceleration? And then, if its good pressure or not? Shouldn't be more than $20, and they might even have some awesome suggestions.

brain fart, no map/mafs combos. i was thinking of baro reading from the maf sensor.

Thanks! I will definetly try this out.

Thanks for the help guys. It looks like it's the fuel pump after all.

Took the car in yesterday to the same guy who replaced the head and the valves. He's a friend of my dad's and he drove the car for a little while and immediately identified the problem as the fuel pump (before driving it he said the plug wires might need changed).

Of course, my dad basically ignored that and said we should run a few more tanks of gas through it to see if the problem would magically disappear. Well, it didn't. I drove it out today to get a pizza and it was so bad I had to pull over 3 times, and the last time it just completely died on me. The rigged up "push button" start we had for the car also went. It shorted out on me and the wires connecting the battery and solenoid caught on fire.

Completely ****ing stressful day. Unfortunately to get anyone to help me with my car I have to get stranded on the damn road. I will be taking auto mechanics at the first available opportunity so I don't have to deal with **** like this ever again.