Startup/Idle issues when cold

Alpine TSi · 12-03-2005

92 GVR4
160K on the ticker
Only mods are EGR removal with all other solenoids and actuators removed(including fuel pressure ones) and a 5 knobby AFC zeroed out.
Recently done head gasket, timing belt, balance shaft belt, head freshening up as it was slightly warped, and water pump.
ECU caps replaced

Now on to the problem. Since it has gotten cold I have run into some problems. When I start it when the engine is cold I have to ride the throttle to keep it running. The car turns over just fine(within 5 revolutions) but it will not stay idling. It will fire up, then die right away. It will not even try to idle up like is should when it is cold. I have to ride on the gas in order for it to run, and if I let off it will either die, or after about a minute of riding it, it will idle really low, almost dying the whole time. Also until the motor gets to it's normal operating temp(190) it is really sluggish, and will max out the knock count for no reason(even out of boost). I am stumped by this and it is mildly aggravating having to sit in my car and give it gas in order to warm it up in the morning. I have a remote start I can't even use.

Any and all help is more than appreciated.

Thanks in advance,
Matt

niterydr · 12-03-2005

Bad FIAV would be my guess.

LightningGSX · 12-04-2005

Check the CTS.If the ECU doesn't know the engine is cold, it won't give it the proper cold start enrichment.

TheBlizzard · 12-04-2005

Quote:

Originally Posted by LightningGSX

Check the CTS.If the ECU doesn't know the engine is cold, it won't give it the proper cold start enrichment.

I was thinking the same thing but usually is will give a CEL after about 30 seconds and then it will start running off a default fuel map and start idling decent. Atleast that has been my experience with CTS being bad.

His problems sounds more like FIAV like Swanny said or maybe the MAF is messed up somehow.

LightningGSX · 12-04-2005

The ECU can only tell if the CTS is shorted or disconnected.As long as the CTS is giving a reading within its temp range(even if its way off), the ECU will assume its working properly.

Also, when the ECU reads a low coolant temp, it should set the ISC at a high idle(up to 1688 rpm on the GVR4) anyway.The FIAV is just as likely the problem, but I would check the CTS first.

Alpine TSi · 12-04-2005

Forgot to mention I replaced the CTS on Craig's advice last time around with this issue. Nothing changed. Does anyone happen to know what the sensor/switch is that goes straight down into the thermostat housing? It isn't there on DSM's as the radiator cap is on top of the tstat.

If I pull the FIAV off what would show me that it is bad?

LightningGSX · 12-05-2005

I don't think there is easy way to check the FIAV.Its not bypassed or hacked is it? If not, I would just clean the hell out of the TB/FIAV/ISC and see what happens.

Alpine TSi · 12-05-2005

No the FIAV has not had anything done to it.

And by that diagram, it looks like the sensor I am seeing is number 3, so it shouldn't really matter if the wires are semi broken on that one as it is just for the AC. The AC doesn't work in this car anyways.

If it gets warmer this afternoon I might be able to yank off the TB and check it out.

Alpine TSi · 01-27-2006

Alright, with the warmer day today I decided to get off my ass and try to look at this.

I pulled off the TB and found that on the side that mates to the intake manifold that was some stuff blocking two passages on the bottom of the TB. This stuff was in between the gasket and the TB and complely block two openings. I had to scrape it all out with a pick tool, it wasn't all that hard of a material but definately wasn't anything I have ever seen before. I then cleaned off the throttle plate and ran some TB cleaner through the whole assembly and even the FIAV. I wasn't able to get off the FIAV as the head of the very last screw holding it on decided it was going to strip out on me.

I then let it dry and put it back on, and no change in the vehicle. Still wouldn't maintain an idle at startup. I backed out the BISS a little and it would stay idling, but only at about 500 rpm. But when the car would fully warm up it would idle about 1300 instead of the factory 900-1000.

Any other ideas? What could that stuff have been? And does anyone have a spare TB they would let go for cheap?

Thanks in advance!

BOVADDICT · 01-28-2006

My car has about the same problem but less severe. These last warmer days have been fine. It also helped when I tightened some of my clamps on my ic piping which were kind of loose and turned out my throttle adjustment screw a bit. Now even the colder days it will run but still bog down or turn off the first start up within 30-40 seconds or so but then start it back up and it will fluctuate but even out after a good 2 minutes or so. So w/e your problem is will hopefulyl figure mine out as well.