Picabo

Let's see here.

Old gas.

Car ran ok in garage immediately after you worked on it.

You took it out for a couple spins. Ran crappy after that.

Could it be that you sucked up some crap from the fuel tank and have plugged the fuel filter?

I think I'd change the fuel filter and see what happens.

rick lambert

Yep, 1/2-3/4. I like the twisty, jiggle too. Every time I have to adjust-it's off to the manual again to make sure I do the order properly. I've done them cold before also, but warmed up is better. Doing it cold is why you-or, rather I normally go with 1/2-3/4.

87 rag

I warmed the car but I didn't get it real hot. I had to keep my foot on the gas to keep it running.
I have all the rockers adjusted now with 3/4 turn and I'm at my favourite part.
Puting the valve covers back on without the gaskets sliping out of place. I think this is the hardest part of the entire job.
I have just washed my gaskets and valve covers with soap and water so that I can get the tack to stick.
Just waiting to make sure they are dry.

I can't be sure but I don't think I sucked anything from the tank. I kept the car in a heated garage all winter and I had my fuel system cleaned 16K miles ago including cleaning out and painting the inside of the tank and replacing the two filters. Once I get it all back together I'll check that next if it's still not running.

I'll report back when done.

Thanks

87 rag

Okay, it's running pretty good now.
Everything back together and i started it up. It still wouldn't idle so I took the throttle body off, cleaned the IAC valve that I took off yesterday and put it on.
I started it agian and it still wouldn't idle. I kept it running until it went into closed loop and it ran on it's own. Ran like crap and the car would shake when the rpms dropped down but it would rev back up and not stall. I let it run for a while while I double checked that I had everything hooked back up and the idle smoothed out bouncing back and forth between 700 and 800 rpms.
I decided it was time for the new gas so i took to a gas station and put a new tank of 94 in it with a bottle of injector cleaner.
After that I went for a 30 mile drive and it seemed to run great. Back into my driveway the car is still hunting a little while it idles but only between 600 and 800 rpms.
I'm going to let it cool down, wash it and see what happens when i start it cold.

Thanks for the help. Don't know if I'm done yet.

mseven

Sounds like you are getting there ......for fear of redundancy, re-check min. air ?

87 rag

Just to be sure the min air is the IAC valve right?
It don't know what else to do to the IAC other than cleaning it and resetting it. I've done this, if you know of something else let me know.
I don't want to stick a pin into a wire to check the current/volts/ohms (I have no idea what I'd be looking for)

I thought of something else I forgot about. I could have a small air leak where the runners meet the manifold. I lost the torx screw that goes by the firewall on the drivers side when I was puting the runners back on. All the rest are tight.

Car is clean now too.
Thanks again.

mseven

That could be your leak !! Which would then moot the following.

What I was refering to in the IAC was to make sure on start up it goes up past idle and back down to the target rpm. Also knowing that if the counts (position) exceed the approximate range it can be to low or high for the ecm to corect.

Part of the re-set that is important is after you have set the idle at 450, shut off, depress pedal slightly re-start for 5-10 sec. shut off, restart. Then readjust, if ness. the tps.

Sorry, I guess I was redundant here regarding this but the mention of "hunting", dropping idle, etc. makes me think it is either still trying to learn or not exactly right..... Now however, after mentioning runner bolt missing this could be aiding in your idle issues.

87 rag

Mseven, thanks for explaining it for me. I actually appreciate you being redundant. I wouldn't have gotten the full explanation if you hadn't brought it up again.

It does start at a higher idle and settle.
I just took it to the store (20 minutes round trip)
It's still hunting. Up and down, up and down. The other thing I notice is that when it gets to the 600-700 rpm range it sounds like it is missing.
it's not a steady rythm. Does this make sense?
I'm wondering about the distributor, rotor, wires, etc. Maybe I'm not getting a spark on all cylinders. Or its a weak spark. It seems to do fine once the rpms are higher when I'm driving around. time to do some more research.

First thing I'll do is replace that torx bolt.

mseven

Definitely get the bolt in, quite possible this could be adding some to idle searching. Now that your lash is set (I am guessing better), and since it is not a radical motor it should be possible to get it to be very smooth.
Yes, going over the ignition is a good idea, cap, check wires etc. Another thought here might be to re-check base timing. Personally I try to cover all the bases, and like I post, I am redundant in trying to be thourough when I am going over the car. Sounds like your on the right track and is getting there.

tigmaned

87
did you adjust your TPS to .54 volts yet? maybe i miss that in one of the posts? i was in the same boat last week on my 86, i am still going to check the timing again, the dist kept moving on me when i went to tighten the bolt back down? set timing, then IAC and then TPS.

rick lambert

GET THAT BOLT BACK IN, vacumn leaks-which you now have make it almost impossible to smooth things out, timing etc. How much gas did you add to the tank? I hate gas sitting, it sours faster than you think and can cause chasing problems till your red in the face, hope you added some Heat, or other additive that displaces water!

AGENT 86

Try increasing you min. idle to around 550 and reset TPS. May help

87 rag

I'll get the bolt in but I never did find it so I need a new one.
Tough to get to a dealership when i work the same hours they are open but I may be able to skip out early or get someone to pick one up for me.
Checking the timing again is a good idea now that I don't need to touch the gas to keep the car running (assumption)

How do I set the base idle to 550? is this with the idle screw?

TPS is something I have never played with. When I used my laptop and scanned my car 2 days ago with TTS Datamaster it was at .55 on idle and increased when I hit the gas.

Thanks everyone.

87 rag

I put a full tank of gas in it. It was on reserve.
I added a bottle of fuel injector cleaner but nothing to get rid of water.
Is it okay to use both in the same tank of gas?

rick lambert

Yep, I've used them both at the same time-and with that low of a tank-you could also be causing problems. especially on corners.

mseven

He is refering to setting the min. air w/IAC fully extended then disconect, start put in drive set air (screw)at 550 rpm , then reconnect IAC the rest of procedure. TPS setting is within spec.

87 rag

Thanks Rick, I'll get some tomorrow.
I've never had a problem on corners before with low fuel but there's a first time for everything. No corners in my driveway though.

My lovely assistant (sorry no link) was at work today but she can help me tomorrow. I was reading your thread on pulleys. I have mine sitting in the garage waiting to go on but I'm not touching them until I get the other stuff corrected.

rick lambert

I keep harping on it since the vette sat-won't hurt a thing, right now you could be sucking up condensation from the tank-best thing is to start from knowns.Good fuel, and no vac leaks, all else is much easier to deal with. but can be mind boggling with bad fuel-or water in it and vac. leaks too. BTW-post a pic-of the assistant

87 rag

Best I could do in short notice.

tigmaned

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i used this.
Procedure
There are two electrical components on the TB that you will be working with: The TPS and the Idle Air Control Valve (IAC). Make sure that the connectors for these two components are easily accessible and that you can easily disconnect the IAC.
You will also be playing with the diagnostic connector under the dash. Remove the cover (if it's still in place). Bend your paper clip into a "U" shape. You will be playing with the two top right hand terminals ("A" and "B") in the connector.
First step is to set the minimum idle speed. If nobody has messed with this on your car before, the set screw will be covered by a pressed-in plug. It's located on the driver's side of the TB. Remove this plug if it's there.
With the IAC connected and the ignition "OFF," stick the paper clip into the diagnostic connector from "A" to "B." This grounds the diagnostic lead.
Turn the ignition to the "ON" position without starting the engine. Wait 30 seconds.
Now, with the ignition still in the "ON" position, disconnect the IAC connector at the IAC.
Remove the paper clip from the diagnostic connector.
Start the engine and allow it to reach normal operating temperature. The idle speed will probably be really low, and you may have to coax the engine a bit with the gas pedal to keep it running for a while.
If your car is an automatic, set the parking brake and put the transmission in "DRIVE." If your car is a manual, leave it in neutral.
Adjust the idle speed screw to obtain 400 rpm in drive or 450 in neutral.
Shut off the engine and re-connect the IAC.
That's it for idle speed. Now on to the TPS.
There are 3 wires stacked vertically on the TPS. You will need to be able to measure the voltage between the two top wires. You can either buy a special harness connector that breaks these wires out (from Mid America), or gently pierce the insulation of the wires with the pointy prongs on your volt meter. You can also stick a paper clip into each of the two top locations of the connector and clamp onto the paper clips to measure the voltage. Whatever is easiest for you.
Turn the ignition to the "ON" position without starting the engine.
Loosen the TPS Torx adjustment screws.
Set your volt meter to a low scale DC volt setting that will accurately read less than 1 volt.
Measure the voltage between the two top TPS wires.
Adjust the TPS by rotating its position until you get a reading of .54 volts.
Tighten the Torx screws and recheck the voltage. Re-adjust if necessary to make sure voltage is right at .54.
Turn the ignition "OFF."