I'm confused...

[gsxboostin]

Hey I am really confused I have never seen this before. When I go to adjust my BISS screw (because I am timing the car) it can be screwed all the way in (tight) and it will still idle and it sounds great no surging, but when I start to unscrew it from tight it starts to surge. Now I know that you are not supposed to be able to screw the BISS screw tight because it would just kill the engine off. So I'm kind of stumped on this. Anyone else seen this before? And second, Once it is started I will go to shut it off, and it shuts off just fine no weird sounds or anything abnormal, then when I go to start it I have to really play with the throttle (almost or most of the time hold it wide open) to get it to turn over, other wise it just cranks and cranks, like it doesn't have any fuel pressure or somthing. The base timing is correct, and the reason I am needing it to run correctly is to do the ignition timing so the CAS is in the almost correct place to run for timing purposes. Thanks for you help... -Matt

:edit: When it is running it sounds like it is "ticking" and its not an exhaust leak noise, its a loud click. And when idling the antifreeze is like boiling in the overflow tank, but the temp gauge reads normal in the middle where it's supposed to be. This is really messed up.

 

[91orangeGST]

THe same thing is going on with my car. 90 4g63t and I screw the biss screw all teh way tight and it idles at 800 rpm's??? The only difference is it starts up perfect?

 

[91lizard]

ok listen carefully

i am not sure what it is called but there is a weird lookin thing on the firewall toward the back of the car you have to have it grounded to set the timing on the car now after the timing is set turn off the car unhook the wire and restart it then you can set the biss screww tell ya what try this

loosen the bolts holdin the throttle cable in place..
loosen the idle screww till it is no longer touching on the throttle then turn the biss screw in till it wont turn in no more (clockwise)
then turn it 3 times (full revolutions)
then turn the idle adjust screw in till it touches the throttle then turn it 3/4 of a turn car should fire up and be pretty damn close
lemme know if this helped

 

[nitroawdtalon]

I am the one working on his car and the first problem is getting it started. If the bliss screw is adjusted properly it will not just fire up. But yes the Bliss screw plays an important role in the running of the car. Now starting the car is a differnt story. We will do a compression test tommorow to see where we stand on that as we know that we are getting spark and fuel. Fuel tested fine for psi. It stands @ 28psi vacume attached. I believe that we just need to put in a coolant cap because it is old and I dont think that it is holding pressure. I belive that the problem may lie in the head being warped. I put in a new head gskt today which eliminated the compression blowing in the coolant viens. It was acctually neat to see on every stroke the coolant to blow out the compression from the cylender when we took the cap off. Never saw that before. I guess my question to this post is does the tps if set incorrectly, have any affect on the starting process?

 

[RoasT BeeF]

Well heres what I think.

You should start by filling up your coolant. That is probably causing most of your problems. It sounds like there is air trapped somewhere in the system. When air gets trapped in the system like that the coolant can not circulate so it just sits there. This is why part of the radiator will be burning hot while the other is ice cold. My guess is the reason your temp guage shows normal is because the temp sensor is inside one of these air pockets and is not getting hot. So you think your cars temp is fine while in fact it is probably overheating. This could also be the cause of your idle surge. If coolant is not passing through the FIAV in the throttle body it will cause idle surge. Add coolant at the thermostat housing while the car is running to make sure you get all the air bled out of the system. Once you are sure its full take a look at the vfaq article on how to properly set your idle and base timing. There are two connectors that must be grounded. One is located on the firewall behind the battery and the other is one of the pins in the diagnostic port next to the fuse box inside the car. Vfaq has pictures and a much better description.

If after all this the car still overheats there is the possiblity that you have a blown headgasket or a warped head. Do a compression and leakdown test.

 

[gsxboostin]

ok thanks a lot, I will keep the post updated when I figure out the problem. -Matt

 

[Jackson]

I guess my question to this post is does the tps if set incorrectly, have any affect on the starting process?

From tweaking my car, yes the TPS does have to do with the starting parameters. You have to do a combination of both TPS and BISS screw to adjust the idle just right.