hard start issues(diagnosed possibilities w/ no luck)

[Nitemare1]

Soooo... Iv had this car going on 2 weeks now. recently developed a hard start issue. I checked plugs, pulled injectors, I can hear the fuel pump come on, changed the fuel filter, all the sensors look fairly new.

The engine spins over fast but just takes a noticeably longer time to start, then the engine starts....sluggishly, and a little un burnt fuel(smoke) comes out the exhaust and it runs fine.

I have not checked compression since the car seems to run out fine with plenty of power considering its stock other than exhaust, which it should because the forum member I purchased it from claimed to have rebuilt the engine 20 or 30k ago.

Any thoughts? weak fuel pump? trash in fuel tank? clogged injectors?

Unfortunately, it does seem to fire right up after it gets warm, a typical sign of worn rings and expanding after start up and firing up with no issues after. But the car doesn't smoke at all, not even the slightest bit of blow by or use of oil.

And yes Iv searched and searched "hard start issues" before someone jumps down my throat about posting witch out searching.

[GTwagon]

Soooo... Iv had this car going on 2 weeks now. recently developed a hard start issue. I checked plugs, pulled injectors, I can hear the fuel pump come on, changed the fuel filter, all the sensors look fairly new.

The engine spins over fast but just takes a noticeably longer time to start, then the engine starts....sluggishly, and a little un burnt fuel(smoke) comes out the exhaust and it runs fine.

I have not checked compression since the car seems to run out fine with plenty of power considering its stock other than exhaust, which it should because the forum member I purchased it from claimed to have rebuilt the engine 20 or 30k ago.

Any thoughts? weak fuel pump? trash in fuel tank? clogged injectors?

Unfortunately, it does seem to fire right up after it gets warm, a typical sign of worn rings and expanding after start up and firing up with no issues after. But the car doesn't smoke at all, not even the slightest bit of blow by or use of oil.

And yes Iv searched and searched "hard start issues" before someone jumps down my throat about posting witch out searching.

first of all do you have any codes?
if not then you really need to do these test for us to help.
the test tell us the health of the engine/vehicle.
if you can do a compression test with a fuel pressure test.
that'll at less eliminate fuel and compression.
if those two are good then check how good your spark is.
finding solutions to our problems is a process of elimination.
so start with the easy things first.

[Legacy777]

Coolant temp sensor.

I'd suggest replacing it, as it affects a lot of temperature related ECU functions, especially starting.

[Nitemare1]

Soooo... Iv had this car going on 2 weeks now. recently developed a hard start issue. I checked plugs, pulled injectors, I can hear the fuel pump come on, changed the fuel filter, all the sensors look fairly new.

The engine spins over fast but just takes a noticeably longer time to start, then the engine starts....sluggishly, and a little un burnt fuel(smoke) comes out the exhaust and it runs fine.

I have not checked compression since the car seems to run out fine with plenty of power considering its stock other than exhaust, which it should because the forum member I purchased it from claimed to have rebuilt the engine 20 or 30k ago.

Any thoughts? weak fuel pump? trash in fuel tank? clogged injectors?

Unfortunately, it does seem to fire right up after it gets warm, a typical sign of worn rings and expanding after start up and firing up with no issues after. But the car doesn't smoke at all, not even the slightest bit of blow by or use of oil.

And yes Iv searched and searched "hard start issues" before someone jumps down my throat about posting witch out searching.

first of all do you have any codes?
if not then you really need to do these test for us to help.
the test tell us the health of the engine/vehicle.
if you can do a compression test with a fuel pressure test.
that'll at less eliminate fuel and compression.
if those two are good then check how good your spark is.
finding solutions to our problems is a process of elimination.
so start with the easy things first.

did you read post??? im on to more advanced diagnostics....

[Legacy777]

Did you read mine regarding the coolant temp sensor?

[Nitemare1]

Coolant temp sensor.

I'd suggest replacing it, as it affects a lot of temperature related ECU functions, especially starting.

hey Josh,

yeah from what I have read the coolant temp sensor seems to give the ECU quite a hard time when its bad

Can I check the ohms and see what the resistance is to tell if its bad? the engine was recently rebuilt and all of the sensor appear to look new, which I know parts fail all of the time.....

other than a ecu/sensor issue I don't know what else it could be. I mean I guess I could check compression but I doubt it has a bad cylinder. it runs too well imo

[Nitemare1]

Did you read mine regarding the coolant temp sensor?

I did

[Legacy777]

You can d/l the service manual from me, It'll have the info on the cts. Check out the stuff you need to know forum for a link to my server. I will say however that checking the resistance sometimes shows it's ok, but it's still bad. They are around $20 from one of the online dealers, so I usually just recommend replacing it.

[Nitemare1]

You can d/l the service manual from me, It'll have the info on the cts. Check out the stuff you need to know forum for a link to my server. I will say however that checking the resistance sometimes shows it's ok, but it's still bad. They are around $20 from one of the online dealers, so I usually just recommend replacing it.

sounds like a plan.... Ill go ahead and swap it out. Also is there a schematic or pic to a link or thread anywhere that shows where all of the sensors or major sensors are?

[GTwagon]

Soooo... Iv had this car going on 2 weeks now. recently developed a hard start issue. I checked plugs, pulled injectors, I can hear the fuel pump come on, changed the fuel filter, all the sensors look fairly new.

The engine spins over fast but just takes a noticeably longer time to start, then the engine starts....sluggishly, and a little un burnt fuel(smoke) comes out the exhaust and it runs fine.

I have not checked compression since the car seems to run out fine with plenty of power considering its stock other than exhaust, which it should because the forum member I purchased it from claimed to have rebuilt the engine 20 or 30k ago.

Any thoughts? weak fuel pump? trash in fuel tank? clogged injectors?

Unfortunately, it does seem to fire right up after it gets warm, a typical sign of worn rings and expanding after start up and firing up with no issues after. But the car doesn't smoke at all, not even the slightest bit of blow by or use of oil.

And yes Iv searched and searched "hard start issues" before someone jumps down my throat about posting witch out searching.

first of all do you have any codes?
if not then you really need to do these test for us to help.
the test tell us the health of the engine/vehicle.
if you can do a compression test with a fuel pressure test.
that'll at less eliminate fuel and compression.
if those two are good then check how good your spark is.
finding solutions to our problems is a process of elimination.
so start with the easy things first.

did you read post??? im on to more advanced diagnostics....

more advanced diagnostics?
all i have to say to that is
K.I.S.S.
Keep It Simple Stupid.

[Legacy777]

sounds like a plan.... Ill go ahead and swap it out. Also is there a schematic or pic to a link or thread anywhere that shows where all of the sensors or major sensors are?

The factory manual will have decent diagrams where things are, as well as the parts manual. These picture show where some sensors are for the non-turbo engine. The coolant temp sensors are on the opposite side of the coolant crossover for the turbo engines.

http://www.main.experiencetherave.com/s ... injectors/

[Nitemare1]

K guys, swapped the coolant temp sensor and cleared the computer.... Car still is hard to start and sort of sputters when it finally starts up, then clears up. Once at normal operating temp it he hard starts aren't so bad.

Any ideas? Check fuel pressure ? Any valves or other sensors to check?

[Nitemare1]

anyone??

[rallyak]

Well,this one is weird test. Take off the alternator belt and see if that fixes the hard start. Once had an alt. that would drag the engine down it would take 5-10 revolutions to start, and sometimes would be flooded. It too would run like crap till it warmed up.

[Nitemare1]

hmmm.... ill give it a shot. at this point its starting to get annoying but i dont want to just start throwing parts at it.

[Nitemare1]

going to do a walbro fuel pump this weekend... I didnt see a fuel press reg anywhere, so i doubt that could be the issue. and sort of vacuum/emissions valve that could cause my hard start issue?

josh? any ideas?

[IronMonkeyL255]

Fuel Pressure regulator is attached to the end of the passenger side fuel rail, right next to the turbo. I would definitely do a fuel pressure check, but if you are changing the pump it would only really be checking the FPR.

Our emissions systems were relatively simple, so I highly doubt that one of those is causing issues (unless maybe clogged cat if you still have any, but that would affect running even after warmup). Even if it were, it would likely throw a CEL at least giving you a hint as to the issue.

Now, just brainstorming here, maybe the bimetallic thingy in the IAC valve causing issues? It also couldn't hurt to clean out the butterfly in it either (I usually just take off the hose leading to it and spray some seafoam in there to let it sit a bit before starting).

Also, you have done a compression check, right? I saw it asked, but didn't see a response.

And finally, HOLY CRAP, another Leggy turbo in the area. I am in upstate SC, and rarely ever see any of these around. I go up to Asheville all the time, and all I see are Imprezas and Outbacks.

[Nitemare1]

Fuel Pressure regulator is attached to the end of the passenger side fuel rail, right next to the turbo. I would definitely do a fuel pressure check, but if you are changing the pump it would only really be checking the FPR.

Our emissions systems were relatively simple, so I highly doubt that one of those is causing issues (unless maybe clogged cat if you still have any, but that would affect running even after warmup). Even if it were, it would likely throw a CEL at least giving you a hint as to the issue.

Now, just brainstorming here, maybe the bimetallic thingy in the IAC valve causing issues? It also couldn't hurt to clean out the butterfly in it either (I usually just take off the hose leading to it and spray some seafoam in there to let it sit a bit before starting).

Also, you have done a compression check, right? I saw it asked, but didn't see a response.

And finally, HOLY CRAP, another Leggy turbo in the area. I am in upstate SC, and rarely ever see any of these around. I go up to Asheville all the time, and all I see are Imprezas and Outbacks.

Any idea of what type of #'s is should be looking for as far as fuel press. goes?

I ruled out compression issues due to it having plenty of power and supposedly had been re built not long before i bought it.... however it could be a bad valve or something. ill do a comp. test this weekend and throw up some #'s

And ictually i bought the car from a member here that lived down in the mills river/fairview area and im right around west asheville, so yeah. right down the street. had a few STi's. just picked this up b/f it was something different. trying to work out all of the bugs now....

[Nitemare1]

anyone else have or had hard start issues?

any remedies or fixes to them?

[IronMonkeyL255]

43.4 psi is what you should be looking for as far as fuel pressure.

[afterthisnap]

I had hard start issues (cranked fine, took a while to "catch"). Cleaning out the IAC helped, but ultimately it turned out to be a pair of bad fuel injectors.

I know it's my go-to answer for everything engine related, but check the resistance at each of the injectors with a multimeter. It costs nothing and is a good next step after reading codes.