Not sure what i did wrong

[soundxtc]

I'm hoping someone has an idea of what i can try. i'm new here and want to thank everyone in advance for the help.

 

I have a '90 subaru legacy wagon with the 2.2l that i picked up cheap, all it needed was a clutch, so i drove it home and started working on it. changed the clutch and other things, and now it doesn't want to run right. here is everything i have done to it (hopefully i haven't left anything out):

 

pulled engine

replaced clutch set

figured while it was out i'd replace a few more things

replaced water pump

replaced timing belt

replaced O2 sensor

replaced spark plugs and wires

replaced fuel and air filters

checked throttle position sensor and it is ok

tried different knock sensor (i think that is what it is, i wasn't the one that did this sensor)

even drained the fuel tank and put some fresh gas in

 

ok, i know the first thing most people will think is the timing belt was put on wrong, i thought so too, so i checked and double checked and ........ about 20 times. i counted the teeth on the belt to make sure it was right, i lined up the markings to make sure it was right and still no go. it misses and backfires. The only way i can seem to make it idle is if i pull the vacuum hose off the brake assist, and then it idles fine and actually seems to run better. makes no sense to me. I actually took it to a subaru "specialist" (at least that's what the sign said on the building, and after 3-4 months he calls me up and say, just come and get this car, i can't figure it out. kinda made me feel better about the fact that i wasn't just completely off my rocker and couldn't figure anything out.

 

it ran so smooth when i drove it home, now, rough, won't idle (with vacuum connected), hesitates, and backfires. any ideas would be greatly appreciated.

[NoahDL88]

did you take the plastic off the air filter?

 

unplug and replug every connector that you may have had apart when you pulled the engine.

 

double check the timing belts, did you have the pulleys off? if so verify the drivers side pulley has the teeth on the back for the cam sensor.

[Twitch de la Brat]

Did you reconnect all the vacuum lines properly?

There are quite a few so its easy to miss on or two.

 

Did you make sure the O2 sensor is plugged in completely?

I just did mine and it was a bugger to get in completely.

 

Also, is everything electrical plugged in?

As you probably noticed, there are a LOT of plugs on this engine.

Chances are you missed a plug or the knock sensor you swapped out is bad.

 

Twitch

 

PS: Is it throwing any codes?

Like a "check engine" light or anything?

[soundxtc]

i have checked to make sure everything is plugged in (vacuum and electrical) but i think i will try to unplug all electrical and plug it back in again.

no check engine light. don't have a code reader

i never took the pulleys off.

pulled the air filter out, so that i know it's getting air.

 

thanks again for the ideas and help

[naru]

The only way i can seem to make it idle is if i pull the vacuum hose off the brake assist, and then it idles fine and actually seems to run better.

 

If this is w/the hose plugged,the brake booster leaks.

 

If this is w/the hose uncapped,you have too much fuel for some reason.

Bad FPR

Plugged return line

Leaky injector

Faulty MAF

Faulty CTS

 

Any codes? Pretty sure you don`t need a reader.

Try running it w/the CTS and O2 unplugged.

[GeneralDisorder]

You don't need a code reader for a '90. Just plug the green connectors together under the dash and the CEL will flash you the codes in morse. There is also a procedure for running a "D-Check" (Dealer test mode) that can be followed and the ECU will do a more refined check of it's systems. I don't know the procedure off the top of my head for a gen 1 EJ but someone probably will or can look it up.

 

Are you sure the fuel lines are installed on the correct nipples? Maybe the supply and return got swapped around?

 

Run a fuel pressure test. Just get an inexpensive 0 to 100 psi guage and T it into the fuel supply line with some FI rated hose and some brass barbs and such. Shouldn't cost much to build. If you have a Harbor Frieght around they sell a test set for reasonable.

 

Check that the idle air control is working. Maybe it's stuck closed or something.

 

GD

[OB99W]

[...]If this is w/the hose uncapped,you have too much fuel for some reason.

Bad FPR[...]

Or the FPR (fuel pressure regulator) isn't getting proper vacuum applied.

[Qman]

Check that the O2 sensors are plugged in!

[Fairtax4me]

Obviously too much fuel/ not enough air.

 

We know that it will idle with a vacuum hose disconnected but how does it drive with it like that?

[soundxtc]

Thanks guys, i will try those things over the weekend and get back to everyone on if i find anything. it just so happens i bought a fuel pressure tester a couple months ago, but it's been too cold to want to work on it much.

[thummmper]

if after all that you still have an idling problem, spray wd40 on the intake gaskets to see if the idle rises from a leak. degumming the throttle body eliminates a lot of mysterious problems that feel like ignition/ igniter.

another great preventative is cleaning and tightening your ground points from the powertrain to the chassis/body.

 

todd