Engine is bucking like crazy?

[rlazier07]

Alright, first off i have a 1993 Mitsubishi eclipse with a 1.8 liter engine and automatic transmission. I have been working on the car with my father for over a year now, we have rebuilt the engine and put a rebuilt tranny in it. I ran the car for about 3 weeks but it seemed to have no power, mind you we have replaced just about everything under the hood. While running the car we noticed it had no power on hills at all, no matter how fast you were going it would die down to about 40. It's sad because my 1990 geo prism could dust this car. We took the throttle body off and cleaned it out, readjusted the idle and timing( the car was at 10 btdc, and we adjusted it back to about 5 degrees btdc). This seemed to help the car run a little better but now when you get in the car and want to go the car will not go. It just bucks as if it is getting no fuel at all, once in a while it will go but i'd say about 95 percent of the time it just bucks and won't go above 10 miles an hour, it's horrible. I have put over 3000 dollars into this car and I just don't know what to do anymore. We checked the injectors with a stethoscope and they are all clicking, the fuel filter was replaced only a few months ago, as well as the air filter. The injectors were supposed to have been done just before i bought the car last year. Optima red battery in it, new alternator, new power steering pump, new timing belt, every belt was pretty much replaced, new coolant temp sensor and sending unit. The problem is, is that i have replaced so many things I don't even know where to look to attempt to solve this problem. Please help I am open to as many suggestions as i can get i will try anything.

 

[reeper]

cat clogged
low fuel pressure
mis gapped sparked plugs

 

[rlazier07]

The question i have is that i never had the problem before i readjusted everything and the plugs i'm running are platinum fours( i know a lot of people don't like them but i've ran them in all of my cars and like them). I really appreciate your suggestions, with the low fuel pressure how would i check that? Also, on my 1.8 we ran a compression test by hooking the gauge up to the spark plug hole and turning the engine over, not starting it. Is this the correct way to do it and what numbers should i be getting out of each cylinder? And i have to check the cat. thanks

 

[drewvr4]

i would bet alot that your timing is off a tooth

 

[rlazier07]

Yeah, we thought that as well, however, when we changed the belt we checked it several times to make sure it was at top dead center and we even had the head off so we could see that it was. We marked the belt and then checked it after we put the car back together, it started right up. We checked the timing the other day by jumping the computer and throwing a timing light on and it looked to be exactly where it needed to be. We checked it several times and the marks line up perfectly. We have tried everything. We read in the haynes book about it maybe being a clogged fuel pump filter, know anything about that?

 

[19Eclipse90]

Sounds like the problem I am having with my 2.0 GS. I believe it is a fuel problem. The car used to throw a CEL when it would do this bucking, but I replaced the MAF and that took the CEL away. However I still have the bucking. The car is getting spark and there is nothing wrong with the airflow now. I have narrowed it down to a component in the cab, it's a gold box on the passenger side of the center console next to the ECU. Everytime the problem occurs, this box starts beeping. I have yet to test it, I haven't had time, but check your manual on it. It is a fuel part I forget the name for right now. I wish I could be of more help but I'm at work so I can't very well go look for myself. When I get home I'll look it up.
Brian

Edit: Also, my car has a new fuel filter, that didn't help any.

 

[rlazier07]

Yeah any more information you may have we could really use because we have narrowed it down to a fuel problem as well. We were having a problem with it not getting fuel before but we thought we fixed it. I think this weekend we are going to check that relay and we may even drop the tank and replace the pump and the pump filter. The lines look like they are in good condition still. Any more information would be greatly appreciated. This is the reason i love this site because i would have never thought about that relay i'll definately check it. THANKS

 

[19Eclipse90]

Chapter 4 page 4 in your Haynes Manual, it is the EFI Fuel Injection Relay. Your 1.8l procedure is a little different from my 2.0l. I just took mine out and I'm about to test it. I'll let you know if it is faulty or not.
Edit: After testing, mine is fully functional.... I guess I'll have to look elsewhere for the problem.

Good luck with yours though, sorry if that isn't the problem either, I tried.