review of my running problems

[Eldorado]

I've decided to start a new thread to deal with my starting/running issues because the old thread wasn't getting the responses I was hoping for.. probably due to it being two topics in one...

you can read the original thread here .

Basically, if you dont want to read that page, the readers digest version is that I replaced my upper rad hose. While in there, I had to push the intake AFS and JBoot out of the way. Got the hose installed... refilled hose with coolant to remove air..

now my car wont stay started. It'll start, sputter, then die. Unless my foot is on the gas to keep it alive. it revs just fine with no (apparent) loss of power.

Most think it's a vacuum leak. Which would make sense, seeing as how I was fiddling around with the intake. I've inspected everything and all lines that can be seen from the top of the engine, ducking from all angles, the Jboot, everything looks just fine.

I dont hear the hiss of a vacuum leak in the engine bay. I'm told that a leak big enough to kill the idle of the car would probably be noisy.

now, to quote my previous post... is there any chance it could be something other than a vacuum leak?
because I sure as heck didn't fiddle with things rough enough to undo them from the back of the engine. I remember the car was on a jack stand with my buddy under it so i wouldn't have pushed/pulled that hard..

and these lines seem very secure and strong...

what else could I have disturbed, hypothetically, by changing the upper rad hose that would cause it to lose idle and stall?

Even take a step further, what could have just coinsidentally caked out at that exact time that is totally independent from the upper rad hose / intake area? Clarks Garage says a faulty O2 sensor could do that... anything else?

it's starting to get nice outside weather wise, and I'm starting to get anxious :P

[nynor]

have you sprayed some starter fluid around the vacuum lines to see if the idle will change? i am betting (still) that you have a vacuum leak. i'd take off the intake hose and inspect it very carefully for cracks. also, with that thing off, you will have better visibility to the other intake hoses, etc.

[Eldorado]

took the jboot out, inspected it, and there are no cracks to be seen.

i haven't tried shooting starter fluid around the lines.. what does that do?

[nynor]

it should increase the idle, if there is a vacuum leak, as some of the starter fluid is then sucked into the intake.

[Razorback1980]

Is the idle control valve connected?

[Eldorado]

to where?
I dont see anything out of the ordinary.

[tgcattle]

I discovered the vacuum line under the manifold was bad, the one with the "y" in it. Mines an 89 model and all the lines were cracked and brittle. I changed um all. I also discovered a blown intake gasket when i pulled the manifold. When I was bleeding my radiator the coolant was being sucked into the #1 intake runner when i pulled the intake I discovered the bad vacuum lines under the intake

[ae1969]

It definitely sounds like a large intake leak. The hoses under the intake usually cause these.

Since you can keep it from stalling by stepping on the gas.

THe flapper door is assuming very little air. BUT your mix is out to lunch so by stepping on the gas you can compensate for the extra air.

Bad O2 probably not. Unplug it.......if you really want to check.

[nynor]

i am betting that the vacuum lines under the intake manifold, somewhere, are not connected/split/cracked/torn and creating a big vacuum leak.

[Granite 944]

Shot in the dark, just from what you've said.

TPS: TU outta the blue, or not connected properly. Just because it "clicks" doesn't always mean its always "good". You may have just gotten (un)lucky here. Check all connections to this AND the AFS. Also peeky at the DME coolant sensor connector while your doing this also. Good luck.

[Eldorado]

Granite, can you be more... umm.. layman? I'm having a tough time understanding fully.. I'm not good with names of components yet..

also, where the parts are that you speak of would be a great help too..

[Slam]

83s don't have the idle control valve, so no worries there. TPS is throttle position switch/throttle switch. Follow J-boot to throttle body and switch is on bottom of throttle body. AFS is air flow sensor - barn door just after air box and before J-boot. I'm leaning (pun intended) towards air leaks, but the AFS connexions may be bad, too. However, if they were, holding the throttle open wouldn't make a difference/keep the car from stalling...

I know! You could change your cam seals!

[Granite 944]

Originally posted by Eldorado
Granite, can you be more... umm.. layman? I'm having a tough time understanding fully.. I'm not good with names of components yet..

also, where the parts are that you speak of would be a great help too..

"layman"?..........Get yourself a copy of the Haynes manual, FSM, and start getting acquainted with your car. You's gonna play.........you's gonna pay. At least know the parts/components of your car. Just a matter of if its gonna cost ya money, or your time researching. Nothing good is gonna come outta this without effort/research on your part. Search feature on this board is a decent source also (once ya sort thru all the BS). Good luck!

[Eldorado]

Slam, thanks for the help... just the answer i was looking for... the throttle position switch was basically all i didn't understand out of all that... i've become very well aquainted with everything from the throttle cable to the air filter recently.. i've had it apart 2 or 3 times in many pieces inspecting (hoping) that's where my fault was.

(and i believe my 83 does have the idle control valve... it's the thing to the left of the throttle cable in this pic, isn't it?)



dont mind the yellow zip ties... i had to do it to drive the car home from my buddy's place after discovering this problem...

what does the throttle switch look like? what should i do once i find it to see if it's causing my problems?

didn't someone say that a vacuum leak big enough to stall the car should be able to be heard with your head under the hood? I dont hear anything.. that's the only reason I'm asking for other ideas here...

Granite, thanks for telling me, basically, to learn things on my own. much appreciated.

[tgcattle]

Take a piece of hose hold one end to your ear and the other around the intake and vacuum lines and listen for a hissing noise.

[nynor]

that is not the idle control valve. that is a mixture screw, if i am not mistaken. when i put my intake back on (my '83) i completely forgot to attach the large vacuum hose that is on the bottom of it. i had exactly the same symptoms you are experiencing and i could not hear the leak. like i said it was a HUGE leak, i could not hear it.

[Eldorado]

where along the bottom, nynor?

[Slam]

nyor's basically right. That's the idle air bypass screw on the left. Basically adjusts how much air gets past the throttle when the throttle is closed.

The TPS is on the underside of the throttle body - the throttle body's under your zip-tied throttle wheel. To get to the TPS you've gotta take out the throttle body, but you can make a quick check of it by unplugging it. The connexion's on the driver's side. If the car runs better with it unplugged, it'll need to be replaced. Sometimes when mine gets wet it'll cause the engine to bog at part throttle, and WOT will perk things up.

HTH

[jwade944]

The idle control valve has a hose that connects to the underside of the intake manifold near the oil fill. You have to lift up the intake manifold to get to it. The inlet hose connects to the J-boot. I am not familiar with the 1983 engine and will assume that Slam is correct, but in 23 years, some cars do not have the original engines, manifolds, etc. The symptom you describe are exactly what I have seen when the idle control valve hose cracked. I think you are looking for a cracked or disconnected large hose. Another possiblity is that the intake manifold has loosened.

[tgcattle]

you could also use an air compressor with the engine shut off. Pressure up the intake with 5-10psi and listen fer a leak. Oh, take the jboot off and seal up the throttle body before you pressure it up. I used a piece of clear plastic