Cold start help!!!!!

[idrum2loud]

Got a cold start issue. IACV was blocked to help with crazy idle. Timing was set properly engine runs good. Since it's been cold very early in the AM I can't get her to turn over. It will want to turn over hear an there but no luck. Once it's close to noon time and warmer out it will start with some help with the throttle. Need some input on helping me to be able to drive my baby to work . Was thinking about unblocking IACV but don't know if all that will be worth it ( has tape ball sucked in hole in TB) any help would be great thanks guys.

[Deuce Cam]

What kind of outside temps are you dealing with? I assume it cranks but just won't turn over/start?

[idrum2loud]

Maybe close to freezing but I am in VA near the ocean so it is t super cold. It just won't start , battery and starter are doing a old job trying lol when I start normally sometimes I have to give a little gas but it usually fires right up...just hates me in the AM

[yoshimitsuspeed]

Cranks and turns over means the same thing. It means the motor is spinning under the power of the starter but has not yet fired or started running under it's own power.
Are you saying the motor spins IE turns over but it won't start or fire?
Or are you saying the motor won't turn over at all or turns over too slowly?

Although you should be able to get it to start in cold weather without the ISCV with just a little throttle input it's still quite likely it is helping add to your problems.
I think removing the ISCV is one of the silliest mods people do to these motors. If you are having idling problems find the actual problem and fix it.
The ISCV is there for a reason and serves a pretty important purpose.

[Deuce Cam]

Are you saying the motor spins IE turns over but it won't start or fire?
Or are you saying the motor won't turn over at all or turns over too slowly?

That's what I'm wondering. I'm assuming it cranks but won't start, otherwise he has other problems.

FWIW my iacv is also deleted. Below 80* it gets harder to start as the temps get lower, but I don't think I've attempted starting it around freezing (my guess is it wouldn't be easy). I've heard other members having problems getting the car started in sub freezing temps with the iacv deleted.

The iacv's on the 16v engines are terribly inefficient. They do serve their purpose; however, everyone I've used idles at 2k rpm upon start up and doesn't drop below 1500 rpm until after 10-15 minutes of driving - well after the engine is warmed up. It's ridiculous.

[yoshimitsuspeed]

The iacv's on the 16v engines are terribly inefficient. They do serve their purpose; however, everyone I've used idles at 2k rpm upon start up and doesn't drop below 1500 rpm until after 10-15 minutes of driving - well after the engine is warmed up. It's ridiculous.

Some people find it annoying. I find it to be part of that 80s charm. Any way you cut it other than using an extra penny worth of gas and a couple extra decibles there is no harm in it.

[idrum2loud]

Turns over fine like it does when it actually starts when not cold. A new IACV is almost $200 and it was blocked so I could get the timing correct and not have it seeking and being wack. I am just wondering if maybe I need to check cold start injector or if a coolant sensor is a factor. The battery and starter are churning the motor fine, as stated.

[yoshimitsuspeed]

I have run through about 5 CO winters without a CSI and many others have as well. It might need to crank two more times to fire on a really cold day but it has never been a problem.
Have you tried giving it just a tiny bit of gas? Like don't hold it down or pump it or anything but just crack the throttle plate open a smidge?
Even then the issue I fear is you will be untripping the idle switch in the TPS which may make the ECU behave differently on startup.

I definitely wouldn't buy a brand new ISCV but they are very simple units. Id be willing to bet it could be salvaged with some cleanup. If not then I'm sure you could find a used one.

It's hard to focus on other things when there is a big thing like this looming right in front of us.
If it's not the ISCV then I would say check for strong spark. Some ignition components can be effected by temp.
If you haven't replaced your cap, rotor, plugs and wires in a while you might start there.

You could also try jumping the fuel pump interlock in the diagnostic box and see if that changes anything.

[idrum2loud]

Cool I will try that jumper. New cap rotor wires and plugs. Maybe a new blaster coil? It has some weird yellow one I want a mSD blaster 2 one like I ran on my first rolla. Thanks for the input guys. Yes I crack the throttle on normal start up to compensate for the IACV being blocked off in the TB. Maybe Iam flooding in frustration in the AM...

[jondee86]

The main reason that IACV's get blocked off, is that the water circuit gets
clogged up with crud. Simple way to test is next time you have the engine
running, see if both of the little water hoses get hot. If water is circulating
thru the IACV then both hoses should get hot. If one hose gets a little bit
warm and the other one stays cool, the water circuit is blocked.

I had to unclog one not long ago, and the water tubes were blocked solid
with rust particles. Took a while to clear them by poking down the tubes
with a thin bamboo kebab skewer, and flushing with water until there was
a good flow in and out. Then drop the whole thing in a pot of boiling water
and watch to make sure the element inside moves... about 8mm IIRC.

Clean the gasket faces and put the valve back on with a new gasket and
o-ring... they should come in a top end overhaul kit. You have to take the
throttlebody off the car to get at the IACV, so its a good time to give the
throttlebody a clean up as well.

Cheers... jondee86

[idrum2loud]

Thanks man I will do this. I talked to the guy who built my motor ( red top high comp bottom with blue top big port head no tvis honda injectors etc ) he told me my timing can't be set with a light per FSM because well it isn't factory by no means lol advancing my timing is more than likely what needs to be done and that will surely help me out a lot with cold start. Thanks for all the input I am going to clean TB and IIRC SOON

[Deuce Cam]

Jondee86 brings up a great point which I forgot about. This happened on one of my old cars. The metal hard lines going to/from the iacv were gummed up with rust, but the actual iacv was completely clear.

[yoshimitsuspeed]

Thanks man I will do this. I talked to the guy who built my motor ( red top high comp bottom with blue top big port head no tvis honda injectors etc ) he told me my timing can't be set with a light per FSM because well it isn't factory by no means lol advancing my timing is more than likely what needs to be done and that will surely help me out a lot with cold start. Thanks for all the input I am going to clean TB and IIRC SOON

OMG man, first of all that was all vital information that should have been in the first post if you wanted help. If you don't say your engine is Frankensteined then we are going to advise as though it's stock.

Timing still needs to be set with a light. You may not set it to factory but it will be a good place to start. With your build I bet factory timing will be about right.
The high comp bottom end is no big deal. You will want to run a little higher octane and everything else should be fine at stock specs. Why didn't you get the superior smallport head? Is your TVIS plate gutted or do you have a proper TVIS eiliminator plate? Why was the TVIS removed?
What's up with the Honda injectors? Are they the right impedance? Are they the right size? Why were they used?

[idrum2loud]

Yes honda injectors are correct. Someone with a similar build used these same injectors fine. TVIS is gutted I am pretty sure. Engine runs strong it shits on a stock blue top all day. Blue top big port heads flow more air that's why it was used. Needs cams to exert full potential but I am not investing anymore money on this motor it was built by a friend and put in my car as it was saved from being junked ( real GT-S body isn't rusted out only was missing motor tranny and has tank ) it also has a GS400 fuel pump but I ditched the stock FPR and have a adjustable one with it set around stock fuel pressure. Deck was shaved on head and had 3 angle valve job port n polish etc. it didn't run right when first built but corrected with a stock head gasket over the thinner one it had before. Sorry I wasn't thinking I forget sometimes what all was done to this thing lol it was checked recently by the shop that built it and it's compression numbers were outstanding. I also upgrading the head venting into catch can per engine shop instruction due to it sucking excessive oil into intake. I am pretty sure advancing my timing will fix my major issue of cold start and I plan to clean and unblock the IACV.

[idrum2loud]

Sorry has tvis delete plate and all EGR removed etc

[yoshimitsuspeed]

The smallport head flows more, makes more power and has more peak potential than the largeport head. This is pretty well known and agreed upon at this point.
The TVIS gives you a broader range of power and more low end. It doesn't even sacrifice high end power until you are a good bit above stock power levels.
A thinner headgasket wouldn't make the car run worse. It could create detonation which could wreck the motor sooner or later.
Are the injectors the same impedance and flow rating? I'm still confused why they were swapped. Saying someone else did it and it was fine says nothing. Most people who try things do something different with no way to monitor the results and just because the motor continues to run consider it a successful mod. If they are the same flow rate then why were they switched?

I don't mean to come across too harsh but it doesn't sound like your engine builder had a clue about building or tuning the 4AGE so I'm just trying to get a better idea of what was done and why.

As for your problem I would set the timing to stock and see how it sounds. Keep a close ear out for detonation or really any change in sound especially in the mid range.
I was just helping a customer of mine with a build running 11:1 compression and poncams and he started getting slight detonation at mid load mid RPM. We suspect it was exacerbated by him not having an EGR. The EGR will reduce knock in this area so removing it actually increases your risks of detonation. If you are running the stock cams then it may be even more likely for you so pay close attention. Let us know what your timing is currently set at as well. I assume that someone at some point set your timing with a light?
I assume you are running premium?
Have you done a compression test lately?

If you were knocking bad enough you could have taken out pistons or rings which will make it much harder to start.
If you were running too retarded on the timing to prevent knock you could have burned holes in your valves.

[idrum2loud]

As just stated compression was checked couple months ago and it perfect. The injectors are easy to find in junk yards ad are cominly used on high comp builds ( I can't remember the specs ) it doesn't detonate I would def know that. It was running rich and fouling plugs but I think once I put that FPR on it that has been corrected for the most part. Timing was set per FSM jumped pins and everything. Everyone I know has deleted emission crap on there 4AG's and one has almost 300k on it bashing at drift events and it's fine so that's not a big deal IMO. The tvis was removed for reasons unknown but I have known of people doing this on similar builds and gaining low end which is ideal for drifting which is all this car does really. I run 91 fuel as was suggested by engine shop. They build race motors and they don't specialize in the 4AG but they know there stuff. The head gasket effected the compression ratio and that's what was causing issues before the guy who had the motor had it figured all out then swapped for a 20v and the engine sat for a while until put in my car. I had the engine builder check it all out when I pulled the engine before building the car up suspension wise etc recently for drift. I thought about throwing red top injectors in and see if that maybe helps me out but I was repeatedly told it wouldn't change anything so I am sure these injectors are about the same flow rate etc just newer and onus easily at junk yards .

[idrum2loud]

Blue top head was used so a manifold mod wasn't needed etc

[yoshimitsuspeed]

Well then, sounds like you know it all.
Good luck with your project.

[idrum2loud]

Lol awesome. Just telling you what was told to me and read on forums for years. I know it isn't a perfect build but it works and is better than a stock blue top for what I am using it for. Your posts have made me think about redoing some things and looking into a AFM to see what's going on with this thing. Didn't know all of that wa needed info for cold start help was just reaching out for some directions to look for issues.

[yoshimitsuspeed]

Lol awesome. Just telling you what was told to me and read on forums for years. I know it isn't a perfect build but it works and is better than a stock blue top for what I am using it for. Your posts have made me think about redoing some things and looking into a AFM to see what's going on with this thing. Didn't know all of that wa needed info for cold start help was just reaching out for some directions to look for issues.

Okay sorry for snapping but it's hard to make suggestions when someone seems so confident in things that you have seen personally need to be questioned.

EGR can be removed from a stock motor without seeing issues but it will help reduce chances of knock. If you up the compression enough there may be a point where the EGR will help combat knock. It is assumed that the ECU advances timing in the areas where the EGR would be active since that's the main way you would see benefits from it being there at all. The experience with my customer having detonation is fact. Whether or not having an EGR would fix it is a theory but a rather solid one.
Just because you can't hear detonation with the naked ear doesn't mean it's not happening bad enough to do damage. I asked if you had done a compression test recently because low compression will make the car harder to start and those symptoms will be worse when it's colder. Two months is plenty of time to go from fully functional to very not healthy.
I don't reccomend anyone do anything to the fuel system without a wideband gauge. If you can't monitor the effects of the changes you are making then IMO you have no place making changes. "Because it sounded right" or "seemed to get better" is 1950s tuning and leaves a lot on the table and risks damaging your motor. If you are interested in making power and getting the most out of your setup then buy a wideband gauge and see how it's doing.

There are two issues a thinner headgasket can create. One is detonation and the other is pistons hitting the head. There is no other issue that this could cause.

TVIS increases low end power. There are many dynos that show this. If you are confident that people have seen gains by getting rid of it then by all means post the dyno sheets.

I need to get to work so I didn't have time to find a good TVIS on vs TVIS off dyno of the 4AGE but check out post 20 in this thread. http://www.mr2.com/forums/threads/1910-TVIS-what-to-do
It's the 3SGTE but there are many dynos showing similar results for the 4A if you look around.