# UGH civic issues (EF) **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [February 24, 2010, 5:16pm UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686 "2010-02-24T17:16:11Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![AShort](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ashort/32/4947_2.png) [@AShort](https://forums.speedlife.net/u/AShort)\ **Post date:** [February 24, 2010, 5:16pm UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/1 "2010-02-24T17:16:11Z")
Okay, well I have a 91 Honda Civic hatch, has a B18a1 swap. The car has been having some issues, stumbling while driving, acts like it wants to stall out. It has a code #10 which is the IAT. Anyone have any ideas what would cause the stumbling? Injectors? I replaced the spark plugs and put some injector cleaner in, i only put it in with a half of tank of gas, could that cause it to stumble? should i check the injectors? if so how? Currently car has no intake, just the throttle body lol, could this cause a problem? i don’t think it would cause it to throw a CEL since the sensor is in the intake manifold. I’m going to check the voltage from it tomorrow and the wires. Another issue, the heat. I replaced the heater core (new), thermostat, flushed the cooling system and its still blowing cold air ☹ I bled the system with the cap off, car has coolant, and its still blowing cold. I’m going to pressure test the system and see if that shows a problem, any other ideas? I’m so sick of this bullshit, I just want to sort it out… now i gotta miss another day of school…ugh fml lol ---
**Author:** ![99\_civic\_si](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/99_civic_si/32/7319_2.png) [@99\_civic\_si](https://forums.speedlife.net/u/99_civic_si)\ **Post date:** [February 25, 2010, 5:34am UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/2 "2010-02-25T05:34:17Z")
sounds like for one, your waterpump is doing nothing or your have a major blockage in either the water pipe or the head…I mean, you should be able to feel the lines that run to the heater core, they are pretty easy to reach. with a swapped car and used parts everywhere, honestly your issue could lie in soooooo many places. Timing could be off, ignitor in dizzy could be on it’s way out, tps could be off, you could be losing compression due to a damaged valve/piston/cyl wall, fuel filter could be clogged, injectors could be sticking, etc…the list really goes on and on. ---
**Author:** ![deebo](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/deebo/32/5218_2.png) [@deebo](https://forums.speedlife.net/u/deebo)\ **Post date:** [February 25, 2010, 7:34am UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/3 "2010-02-25T07:34:26Z")
these cars have coolant temp sensors? ---
**Author:** ![SOLITUDE](https://avatars.discourse-cdn.com/v4/letter/s/c37758/32.png) [@SOLITUDE](https://forums.speedlife.net/u/SOLITUDE)\ **Post date:** [February 25, 2010, 8:03am UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/4 "2010-02-25T08:03:38Z")
um…yea what do you think turns on the rad fan? ---
**Author:** ![deebo](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/deebo/32/5218_2.png) [@deebo](https://forums.speedlife.net/u/deebo)\ **Post date:** [February 25, 2010, 8:17am UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/5 "2010-02-25T08:17:08Z")
technically the fan switch does, fggt ---
**Author:** ![AShort](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ashort/32/4947_2.png) [@AShort](https://forums.speedlife.net/u/AShort)\ **Post date:** [February 25, 2010, 9:13am UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/6 "2010-02-25T09:13:41Z")
> [@99\_civic\_si](#): > > sounds like for one, your waterpump is doing nothing or your have a major blockage in either the water pipe or the head…I mean, you should be able to feel the lines that run to the heater core, they are pretty easy to reach. > > with a swapped car and used parts everywhere, honestly your issue could lie in soooooo many places. Timing could be off, ignitor in dizzy could be on it’s way out, tps could be off, you could be losing compression due to a damaged valve/piston/cyl wall, fuel filter could be clogged, injectors could be sticking, etc…the list really goes on and on. well it has a new water pump and timing belt. I;m going to check the timing today. I did a compression test yesterday, cylinder 1 was the highest but they were all within 15% of each other. and whats strange with the heat is, the heater core is warm, the lines are warm, but the air is cold :gotme: ---
**Author:** ![psychopjv](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/psychopjv/32/7251_2.png) [@psychopjv](https://forums.speedlife.net/u/psychopjv)\ **Post date:** [February 25, 2010, 9:21am UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/7 "2010-02-25T09:21:11Z")
> [@AShort](#): > > well it has a new water pump and timing belt. I;m going to check the timing today. I did a compression test yesterday, cylinder 1 was the highest but they were all within 15% of each other. > > and whats strange with the heat is, the heater core is warm, the lines are warm, but the air is cold :gotme: so you answered your own question. the blend door may not be switching to hot when you move it. have someone move the switch while you peek at it. ---
**Author:** ![AShort](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ashort/32/4947_2.png) [@AShort](https://forums.speedlife.net/u/AShort)\ **Post date:** [February 25, 2010, 9:35am UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/8 "2010-02-25T09:35:16Z")
> [@psychopjv](#): > > so you answered your own question. the blend door may not be switching to hot when you move it. have someone move the switch while you peek at it. yeah youre right, i did lol. I had the dash out a few days ago when i replaced the tstat and flushed the cooling system. I made sure the air was blowing to the core and it was, it’s just not getting warm. i dont understand it, very aggravating. ---
**Author:** ![SilverGT](https://avatars.discourse-cdn.com/v4/letter/s/8dc957/32.png) [@SilverGT](https://forums.speedlife.net/u/SilverGT)\ **Post date:** [February 25, 2010, 10:20am UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/9 "2010-02-25T10:20:05Z")
this might be a stupid answer but when you slide the knob to heat does it feel like its working? Check both side of the heater core hose. are both of them hot? if they are not hot the switch that lets the hot radiator fluid to the heater core is broken or not open for hot antifreeze to go to the heater core. check that out. ---
**Author:** ![AShort](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ashort/32/4947_2.png) [@AShort](https://forums.speedlife.net/u/AShort)\ **Post date:** [February 25, 2010, 10:22am UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/10 "2010-02-25T10:22:38Z")
> [@SilverGT](#): > > this might be a stupid answer but when you slide the knob to heat does it feel like its working? > > Check both side of the heater core hose. are both of them hot? > if they are not hot the switch that lets the hot radiator fluid to the heater core is broken or not open for hot antifreeze to go to the heater core. check that out. the heat knob on my hvac is broken lol. the valve is letting coolant in, both hoses are hot. i dont get it, its bullshit lol just checked the timing, its off a bit. im gonna fix that and see how it is. thanks everyone for the input so far! ---
**Author:** ![SilverGT](https://avatars.discourse-cdn.com/v4/letter/s/8dc957/32.png) [@SilverGT](https://forums.speedlife.net/u/SilverGT)\ **Post date:** [February 25, 2010, 10:35am UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/11 "2010-02-25T10:35:41Z")
> [@AShort](#): > > the heat knob on my hvac is broken lol. the valve is letting coolant in, both hoses are hot. i dont get it, its bullshit lol > > just checked the timing, its off a bit. im gonna fix that and see how it is. thanks everyone for the input so far! I still think its the that valve. do this lol Start the car let it warm up to operating temperature turn on the fan to high Open hood Go to the Valve take the wire connector off so you can move the valve independently push the valve lever toward the firewall get inside see if there any heat, if no heat go back to the lever pull it toward the front of the car get inside and check for heat. If no heat, then the system is ok. If you do get like a sprint of heat then it turns cold then there is no flow of antifreeze through the heater core. so further examination is needed. see why its not flowing. If there is absolutely no change in the temp at the vents when you are doing that then my guess is the heater core is blocked from behind or in front with something and its just drawing air from out side the car and recirculating it. What to do after taht? take out the blower motor. and put your hand close to the heater core and check to see if warm. if its warm/hot then soemthing in your vent is broken? maybe the flap to go from closing outside air to heater core is not flipping over? lol i have no clue on that ---
**Author:** ![AShort](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ashort/32/4947_2.png) [@AShort](https://forums.speedlife.net/u/AShort)\ **Post date:** [February 28, 2010, 2:24pm UTC](https://forums.speedlife.net/t/ugh-civic-issues-ef/79686/12 "2010-02-28T14:24:15Z")
> [@SilverGT](#): > > snip thanks for the info bud, i messed around with the valve and no change in heat. im gonna take out the dash, and heatercore box to see if anythings blocking it. also fixed the sputtering issue, turned out to be a bad cap/rotor in the dizzy :tup: