imported_alwaysoverkill

Noticed my car now has a rough idle, its like chug,chug,chug,chug,chug like a muscle car sounds when parked.

It does it worse when in drive (auto) but also does it while idling.

It has had a full tune-up and otherwise runs well, except its down on power and when the AC is on its extremely bad.

any ideas?

Engine is D15B7 from a 93 DX hatch with 241,000km

tazB

***EDIT...

I read the whole thread wrong, dont follow my steps.

kwikb16a2

what the hell are you talking about???


what exactly did u do with the tune up?

imported_alwaysoverkill

tune up was:

air filter
fuel filter
plugs
wires
cap
rotor
oil change and filter
coolant flush
brake fluid flush
automatic tranny fluid flush


blows no smoke but burns some oil, always has since I got it 2 months ago.

imported_SilverSleeper

Clogged Fuel Lines or Injectors might be it.

imported_kickz

hrmmm
maybe you crossed the wires ??
what kinda spark plugs did you use ??
is everyting tight ??
check if the rotor is loose
did you bleed the coolant system??
or just fill it ??
that might be your problem

imported_alwaysoverkill

Tune-up was done back in May. This current engine problems started while in NY for a weekend last weekend.

Tune-up was no problems, coolant was bled, rotor was tight, and car ran perfect after tune-up, noticeably better then before the tune-up.

current Problem is better while in neutral but it still does it then, throw it in drive and its bad. AC drains even more so AC can't be used while car is running like this. I think I may have to take it in, but figured i'd ask if anyone had simular problem, their outcome, etc.


Car also feels noticeable down on power, but with only 102hp stock, it dosen't take much to feel down on power.

imported_BlazeInEk

Check to make sure the spark plug wires are in tight?

imported_weiRtech

if you aren't getting a cel then it is probably either spark or fuel. most of the suggestions above are a great start. i'd also be inclined to just have a look and see what kind of vacuum you are getting in your intake manifold. probably a stretch but could it be your iacv?

imported_alwaysoverkill

ya, no check engine light, which is odd because it really is running like crap. Thanks for all the suggestions every, i'm gonna play around with it tonight

1sloweg

wut do the plugs look like.

imported_alwaysoverkill

Took off the plug wires to test for spark, all wires are fine and plugs are ok.

But, with the car running remove plug wires one at a time and the car almost stalls with 1-2-3 removed, but with the 4th wire removed no difference in idle. When you rev the car up with that wire removed it makes a difference, but at idle it runs the same with the 4th wire plugged in or removed.

i tried the same thing by removing the wire at the distributor cap, same results. but place that 4th wire near a bolt and you can see the spark no problem.

so now i know its not spark related but whats the deal with the 4th cylinder? if I remember right, car should damn near stall with any plug wire removed.

starting to think this isn't good. also, car did not want to start tonight at work, finally after 2-3 minutes of trying it fired up.

I'm starting to think compression test, but wouldn't it run alot worse if the 4th cylinder is crap?

Spoke over the phone with a friend mechanic and he confirmed what i've been thinking, dead cylinder in cylinder number 4. by reving it, its forcing that cylinder to go, but at idle its toast. I'm gonna buy a compression gauge tonight and see what the engine is doing. In the mean time, no smoke or anything, already burns oil, so i might as well keep drivin'er. just no long trips for now.

imported_alwaysoverkill

Compression is

1 - 155 (oil in spark plug)
2 - 175
3 - 180 (oil in spark plug)
4 - 90

so cylinder 4 seems like its toast.

Would love to throw in a nice swap but this is a beater car, so i'm thinking another D15B7 or possibly a JDM D15. 30hp increase is 30%, so it'll be noticeable and still give me good gas mileage too.

dingus888

weird...I'd say seafoam that cylinder adn throw in some engine restore garbage to doctor it but that's just me seeign how it's a beater

imported_alwaysoverkill

Oddly enough I had some Slick 50 so I ran it through before going on a 100km drive and now it idles fine and power is restored...somewhat.

I'm going to do another compress test and see if the slick 50 made any difference on the results. If all it takes is slick 50 every 2-4 weeks, i'll just do that.

I'm thinking the Slick 50 helped get the compression up to 120ish so that cylinder is not lagging so far behind, but i really don't know.

The car already burns oil so i'm worried seafoam will just make that worse by cleaning out the carbon deposits built up on a 240,000km beater.

imported_alwaysoverkill

Re-tested compression again and its normal now.

1 - 175
2 - 180
3 - 180
4 - 175

Also, pulled off the 4th spark plug wire and now its normal, car almost stalls where as before no change at all when plug wire was pulled off.

so for now anyways, problem solved.