Rough idle and no vacume?

Gravy · 11-27-2006

Ok, some people may remember i was doing a HG a while back on the car, and have been short on cash and time. So the HG is on, belt and everything is installed and the timing is on. First time i started the car up, it didn't want to go, had issues, and would turn over only a few times before dying. Sadly, nothing new for this car. But when the car starts... i've got a bad exauhst leak(boost does't come online till arond 4,000 rpm) and i've delt with this before, and can do so again.

Before when working on the car, disconecting a vacume line on the brake booster on the car would result in the slow stall of the car. Today, out of curiosity i thought i switched up the two lines on the back of the car going to the EGR. So i remove one with the car running, nothing happens. Switched the two lines up and still... nothing. Rough idle and HORRIBLE idle surge. I pull a larger vacume line going to the brake booster and.... nothing happens. Out of curiosity i pull every vacume line from the intake manifold and the car still runs the same. Horrible idle surge and the car's boost guage shows -20 vac(yes, aftermarket). Anyone else scratching their head? It fluxuates normally when the gas is stepped on, rests on dead center zero when turned off and i notice a difference in the acceleration in the car between 10 psi, and 14 psi. When the TPS wire is removed the car no longer idles... but revs very high.

So, i decide i'll follow someone's sugestion to re-set the BISS screwed all the way in, and then work it out to get your desired idle speed. Turns out the screw was all the way out and after screwing in the screw to get around a 850-900. I re-conect the TPS wire and the idle stays the same. After taking the car out for a spin... the fluxuation in the engine or the "Surge" is gone, but it's almost like i'm starved for power untill the car starts to build boost, then takes off just fine. Much like i have a vacume leak or something. All lines are on as the were before, no leaks(carb cleaner check) and still when i pull a vacume line the car still doesn't kill. RPM's drop but it's still doesn't kill.

Would a vaulty installed boost controler cause this issue or possibly a block plate on an EGR valve? Also do i just remove the vacume lines on the EGR and hook them into one another or what? I cant tell if i'm leaking any exauhst on the EGR or not, but it doesn't feel like it when i hold my hand back there.

Any help would be great, and if i forgot anything... im sorry to make you read this much to not have the information you needed...

TheBlizzard · 11-27-2006

I would re-check the timing again. Its sounds like you are off a tooth or so. I have had this happen before (not this serious) and it was because the timing was off a tooth.

94talonawd · 11-28-2006

Umm... sounds to me like your timing is off a tooth like what Blizzard said.

I had the same problem. Did you check your base timing? Check that, and see if the line stays right on one spot. If it is floating around one spot, then your timing is off a tooth. One tooth makes a big difference.

Blocking your EGR doesnt make your car idle surge nor does a faulty boost controller. Check the timing and do a boost leak test would be the first thing I would do. Do that, and get back to us ok? And then we'll see what do do from there.

Gravy · 11-28-2006

Don't have access to a timing light... but i dont' see how timing being off causing the issues i'm having with the idle and rough start. When we got the car it didn't start right, just coughed it up to being an old car. Now, who knows, and who cares. As long as it turns over it's all good.

I checked the timing 4 times when i installed the belt, i'd be willing to bet a kick in the nuts from everone on the board that it's on. But i'll check shortly. Car is going to Febo tomorow by the sounds of it, but i'm sure the timing is on.

I re-adjusted the BISS and fixed the exauhst leak... kinda. Got the full spool to 3k ish with one exauhst stud missing. Found the issue i think... i had the vacume lines going as follows,

Boost source from turbo elbow to a T going to the MBC and the intake.... don't ask the car was in 200 parts when i first did it. Didn't know 1 pull of 17 psi could turn your manifold glowing orange.... :-D Set it to 14 psi and drives like a champ.

Pushit2.0 · 11-28-2006

I would have someone else who knows what they are looking at check your timing marks and then use a timing light to set the base timing. Also 94talon with a CAS sensor on a mitsu the ignition timing will drift as much as 1 deg advanced or retard from what you set it to, just from the play in the timing belt and from the CAS to cam connection.

~John

Gravy · 11-28-2006

After doing some thinking, and tring to put everything together... timing must be off. I'll have to check it over the week/end and double check. I made sure it was on at least 4 times putting it on, and i guess i'm blind as hell. I had 150-150-125-150 for compresion before the HG. Now i run 130-130-125-130. So, the car's got a new HG and still needs a leak down test. Gota love DSM's.

I think my Exauhst cam is off, but i'll have to find out in a little while. Try toying with the car shortly.

Gravy

Pushit2.0 · 11-29-2006

Quote:

Originally Posted by Gravy

i'd be willing to bet a kick in the nuts from everone on the board that it's on.

lol

I would think the Intake cam is off a little, which could cause the ignition timing to be retarded, or they are both off, either way if your compression is lower then before with the same gauge and tested in the same way something is not right. I would try to get a logger on there also to see if something looks off with the ecu/sensors.

~John

94talonawd · 11-29-2006

Quote:

Originally Posted by Gravy

After doing some thinking, and tring to put everything together... timing must be off. I'll have to check it over the week/end and double check. I made sure it was on at least 4 times putting it on, and i guess i'm blind as hell. I had 150-150-125-150 for compresion before the HG. Now i run 130-130-125-130. So, the car's got a new HG and still needs a leak down test. Gota love DSM's.

I think my Exauhst cam is off, but i'll have to find out in a little while. Try toying with the car shortly.

Gravy

Early Merry Christmas!

niterydr · 11-29-2006

My vote is that the marks "look" on, but one is slightly advanced and the other is slightly retarded.

94talonawd · 11-29-2006

Oh yea, try shooting the timing gun at the cam gears, there should also be two white lines there that you can see.

Gravy · 11-29-2006

Borrowing a timing gun over the weekend, going to see if the gears are off or if the cam sensor is just off. Idles fine and drives great in 3rd gear around 4-5k rpms. Pulls like crazy in that range as well, so i don't think it's off to bad. But i'll put the light on it and see what comes out of it.

Hope to get the timing set, figure out how far off it is, and fix it before X-mas. I set my goals low, and shoot to do better.