car problem

tnm27 · 02-28-2007

i have a 91 eclipse. i don't know what the problem is but there is what happened. i was on the highway and thought i'd try the car out. so i downshift from fifth to fourth and nothing but when i downshift to third at about the 5,500 rpm the car started to stumble, it sounded like maybe it was backfiring as well, and it wouldn't go pass 5,500 rpm. if any knows what the problem is or what is causing it to act like that any info would help. thanks.

xveganxcowboyx · 03-01-2007

Some more info on the car would help.

If it is turbo I would check your intercooler piping. Look for leaking couplers or anything else out of the ordinary. It's a good place to start.

HiImBrian · 03-01-2007

Sorta sounds like fuel cut.

DBMajik · 03-01-2007

The first thing I would check is your base timing, since it's the easiest. Then go to boost leaks. Then ECU caps.

tnm27 · 03-01-2007

here is what i have in my car:

stock 91 turbo awd ecu
stock fuel system
stock 14b
greddy type s bov
3in apex exahust system with n1 muffler
cometic headgasket
...thats all i can name that really has anything to do with the motor or anything that has to do with this problem..

i checked all piping and seems to be good...timing i will do soon (once this snow storm is over and i can get my car to the garage)...as for ecu caps, the ecu is doing fine...i've been able to pull with this ecu w/out this problem occuring. this is a first.

one thing i should mention though. i don't know if it has anything to do with the subject but yea...i bought another ecu recently and the guy said that the caps needed to be replace soon. i put it on the car and the same thing happened but at 4000 rpm...it was staggering and backfiring...etc.. than i switched it with the normal one and now its happening to that one...(thats the one i have on now) just a thought. if it matter.

thanks guys.

tnm27 · 03-01-2007

Quote:

Originally Posted by Mr.98GSX

Sorta sounds like fuel cut.

can u go into depth? sorry, i'm ma noob to the dsm...so yea. i have noticed though, something fishy or funny bout the fuel gauge and my fuel...hmmm...thanks.

DBMajik · 03-01-2007

Quote:

Originally Posted by tnm27

can u go into depth? sorry, i'm ma noob to the dsm...so yea. i have noticed though, something fishy or funny bout the fuel gauge and my fuel...hmmm...thanks.

It can't be fuel cut unless you're over 19psi. However you'll feel it when you hit fuel cut.

A galant vr-4 I was looking at buying had this same problem and I never actually figured it out. Bringing the base timing down did help, but didn't completely rid the problem. However I never did a boost leak test.

My next guess would be the fuel pump, after a good boost leak test.
To do boost leak tests you should use soapy water on the couplers.

HiImBrian · 03-01-2007

Yea your right its not fuel cut. I didn't know what turbo and how much psi u were running. Fuel cut is pretty much when you have more air than fuel going into your engine and your engine kinda gets drained and stops accelerating for a sec.

tnm27 · 03-01-2007

i am running about 12 psi with a 14b.

Pushit2.0 · 03-01-2007

Quote:

Originally Posted by Mr.98GSX

Fuel cut is pretty much when you have more air than fuel going into your engine and your engine kinda gets drained and stops accelerating for a sec.

No, fuel cut is the ECU shutting off the fuel injectors, this happens when the mas airflow sensor reads to many Hz(to much air). Check for: Boost leaks, fuel pressure/flow problems, base timing, plug wires, coil packs, transistor pack, injectors failing, fouled plugs, that is where I would start looking.

~John

HiImBrian · 03-01-2007

Quote:

Originally Posted by Pushit2.0

No, fuel cut is the ECU shutting off the fuel injectors, this happens when the mas airflow sensor reads to many Hz(to much air). Check for: Boost leaks, fuel pressure/flow problems, base timing, plug wires, coil packs, transistor pack, injectors failing, fouled plugs, that is where I would start looking.

~John

Thats pretty much what I said but in more newbish terms. The engine doesn't get enough fuel because the mas reads too much air. Not tryin to argue or anything, because I'm sure you understand the topic at hand more in depth than myself.

munchgsx · 03-02-2007

Try changing the spark plugs first.

tnm27 · 03-02-2007

alright, here is what i'll do, i'll probably start by changing out the spark plugs, spark plug wires, i've already checked for any vaccum or air leaks (visually) nothing is loose, i will peform a boost leak test this weekend, i am away in college right now, and don't have any of the tools. i have also notice the lights flickering now as well, is there any relation to the problem the car already has? thanks.

Pushit2.0 · 03-02-2007

Check your alternator fuse in the engine bay fuse box, should be 80amps. Then head to a Napa or similar and have they test the alternator/battery in the car.

~John

tnm27 · 03-02-2007

hmm..i just got a brand new altenator, and battery, the battery is a wal-mart chepo one though, i got it cause when i bought the car, it needed a new battery so thats why i got.

DBMajik · 03-02-2007

Quote:

Originally Posted by tnm27

hmm..i just got a brand new altenator, and battery, the battery is a wal-mart chepo one though, i got it cause when i bought the car, it needed a new battery so thats why i got.

Brand new? Remanned? or used? I've heard the remanned ones are crap from napa. But like John said, check the alt. fuse. It caused a lot of weird crap to happen electrically to my car.

tnm27 · 03-02-2007

yep, i bought that altenator brand new. i just bought brand new spark plugs and new plug wires, didn't do much difference, i'll have to go check the alt. fuse. i'll give more info when i get some. thanks.

tnm27 · 03-13-2007

aight, heres an update on the problem...i bought a new used one from one of the guys from the club. installed it than, took it out for a test drive, everything seems to be fine, till i downshift that is, i t squeals for a bout a quick second when i put it in from 5th to 2nd and 5th to 3rd, it makes it 6000 rpm the fist time, than i tried it a 2nd time but than it only makes it to about 5,500. it did manage to make it to the redline at 1st and 2nd starting from a stop. i retightened everything and took it out again, same thing.i read the other forum about the "squealing altenator" and i think we have different situations so yea...hhehehe...any help would be helpful. thanks.