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1994 300zx Seafoam Disaster

02-15-2008, 12:55 PM
I recently purchased a 1994 300zx with 160k miles on it. The previous owners seem to have abused it and there was no sign of any regular maintenance. I heard about seafoam from my friend who said it worked wonders with his high mileage car. Well I purchased the seafoam and followed his directions (full can in a full tank of gasoline... half can in oil... half can through a vacuum line... then a little deep creep in the throttle body) and since then the car hasn't ran. Engine turns over and every once in a while it will get to the point where it sounds like it wants to start. It has started once and ran for about 10 seconds before it died and on a seperate occasion it started off of a push start in 2nd and drove about 100 yards before it died. Since then i have changed the spark plugs (it really needed them) and a rotted coil. Please any suggestions on how to get this car running would be greatly appreciated. I'm a very hands on person and it would kill me to have to pay someone else to fix this.:banghead:

02-16-2008, 02:03 AM
the injectors got fouled most likely... depending if you can have the car down for a period of time, you can pull the injectors (not fun) and send them off to be cleaned... or you can purchase a set of used injectors from someone who has upgraded and install them if you can't have a large amount of downtime.

provided that it IS the injectors... i've heard of horror stories of people having the timing belt jump a few teeth using that stuff... but i've never personally seen an example of it.

one thing you might want to try is to stick the car in neutral, turn it over by hand and carefully feel for any large resistances to it turning over... this will tell you if there's been any real catastrauphic failure.

02-16-2008, 12:53 PM
alright thanks for the suggestions... ill try turning it over and will get back with the results

02-16-2008, 01:18 PM
Sounds like you loosened up a bunch of crap into the cylinders. You replaced the plugs and it still won't run.....mmmm
Check for spark.
You may want to try some starting fluid in the TB. If you get it started I'll bet you'll smoke out the neighborhood.
I wouldn't let run it much with SF in the crankcase. It thins out the oil and is tough on seals.

02-17-2008, 04:50 PM
Sounds like you used wayyyy to much SF than you should of. You should have eased it on her instead of stuffing it into every hole she had.:iceslolan

anyways, Drain your oil first of all. Getting to the injectors is no easy job as it requires a plenum pull.

02-18-2008, 03:43 PM
Well I checked for problems with timing belt... everything checked out fine. So since I realized that at the time i had no idea where those injectors were on this car I pulled out the spark plugs again, cleaned them off, and the motor air out a bit. Later that day I put everything back together and tried to fire her on up. To my surprise she fired right up and was running pretty smoothly. After about 5 minutes of just letting it idle one of my friends decided it was time to give it a little throttle. After just touching the throttle the beast gave one last sickly roar and went back to sleep. It wouldn't start again that night. I removed all the spark plugs and let the motor air out until i went at it again the next day. After putting her all back together it fired right up again. This time I let it idle for early a half hour. When I sat down in my seat getting ready to ease in some throttle I realized the seat was too far forward for me to fit (I'm over 6 feet while my friend who was in it before me is around 5'8''). I pull the lever and the seat slides back and hits the far back position pretty hard. As soon as the seat hits the motor dies. That was yesterday. Today she sputters and dies and I'm getting pretty damn frustrated. I don't think that it would be the fuel injectors if it starts up and runs but I could be completely wrong. Any suggestions?

02-20-2008, 01:26 PM
How much gas is in the gas tank? maybe it needs fresher (read without seafoam) gas. Just a thought.

02-20-2008, 01:42 PM
should have followed the directions per the websight. Sounds like an O.D. to me.
the can tells the basics.
You have way too much in the engine. Hence the fouled plugs.
What vacume hose did you feed the engine with?
If your gas tank was full, your ok. A min. of one ounce per gal. is no problem.
Seafoam will clean out your fuel tank too so a fuel filter will be needed soon.
mabey twice.
Drain the oil, replace. If you just did a filter your ok to not change that.let it mix.
I dont know what to say about the seat issue and the engine.
Next time it runs, everytime you rev it up your gona suck in that seafoam and the engine will die, or want to, seafoam does not burn like fuel.
May take a bit to run this through the system. Heat from the engine should evaporate most of it so Let it idel for a few hours before reving it up.
Or rev it just a little every once in a while and work it through the system.
Do you think the seat stoping hard and the stalling could have been a coincidence?

01-14-2009, 07:52 PM
oh man im sorry for your troubles. just keep at it man. i also had a seafoam disaster. i had put about 1/3 of a bottle in the gas tank, oil filler, and brake booster vacuum line. Everything was ok for about 5 mins (was smoking out the back real good) then all of a sudden the rpms just dropped to 0. I tried to restart, but it just sounds like a dead battery would. I changed the oil and still nothing. Any help would be appreciated?

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