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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
So on a whim, I checked the timing after disconnecting the wire. The mark was about 1.5 inches below the timing tab. I adjusted it to +6° and now the idle is about 1000-800ish in park, about 600 in drive. But choppy. I reset the IAC by turning key to on, disconnecting, then shutting off, reconnecting. Now the car wants to idle but sometimes drop causing it to stall. (In drive). Should I take the car for a drive so it can relearn? Not a daily driver, currently parked in the garage for the winter. I try to sparingly take it for rides due to it being unplated/uninsured. Just got the car and learning as I go.
Hey thanks for the advice. I'll head out and disconnect it now. Ill post the results tomorrow as I am taking it for a ride in the morning. Glad I live in a very large private community with private roads
Looking good! here's an article from the How Tos section. You may have
reconnected the IAC too soon, hard to tell from your post. Check this out https://www.thirdgen.org/tpimod2/
good luck!
I looked all over for that torx screw when i had the throttle body off. I cleaned all the carbon and stuff out of it. Didn't see one. Managed to break off both bolts to the throttle position sensor too of course lol. Fixed that, adjusted with a meter. I however didn't do the paperclip thing because i figured that was related to the torx screw idle adjustment. I have the battery off now and tomorrow morning ill do the IAC again. Should I use the paperclip? I figure A & B pins are the two on the top right of the connector, but im unsure. Ill see if I can find a pinout image for it.
I looked all over for that torx screw when i had the throttle body off. I cleaned all the carbon and stuff out of it. Didn't see one. Managed to break off both bolts to the throttle position sensor too of course lol. Fixed that, adjusted with a meter. I however didn't do the paperclip thing because i figured that was related to the torx screw idle adjustment. I have the battery off now and tomorrow morning ill do the IAC again. Should I use the paperclip? I figure A & B pins are the two on the top right of the connector, but im unsure. Ill see if I can find a pinout image for it.
I think you need to do the paper clip deal to get the IAC seated. The torx screw is on the TBI, not sure where to set the idle on a TPI. The screw is behind a thin plug over it on the TBI, maybe someone will chime in about how to do it on the TPI. You don't plug the IAC back in until the idle is set though, but you do remove the paper clip before starting engine
Thanks for the info. I'll definatally try it in the morning. I took it for a drive again tonight. I got on it and went all the way through first, second, and half of third. Went around a curve with foot off gas and it died. I was like OH SH*t. It started back up with some coaxing. Got it turned around, and turned into the driveway and it died again. I pulled the timing wire, checked and it had gone back to 4° on the timing. I adjusted it again to 6°. I'll do the paperclip/IAC in the morning and see how that goes. I'm wanting to tear this tpi out and put a carb in. This computer crap drives me nuts. I wanna drive it with my foot. Not a computer LOL. We'll see. I'll keep the updates coming. It's getting rebuilt anyways. Hopefully start that in a month.
Update. Completed the checklist for the Timing, IAC, and TPS. Car still stalls driving down the road. I went through all the vacuum lines under the hood including under the plenum. everything is good there. I am trying to understand how the car ran so well with the timing extremely retarded and when its set to spec just dies all the time. Previous owner must have really did a number on this thing. If there aren't further suggestions I think its time to start ripping this motor out for a complete rebuild. Get this block and heads out to a machine shop for an overhaul and new bearings and then start putting all new internals in. Summit has a nice rebuild kit complete with pistons that I have my eye on. Thanks for all the help guys. I love this forum as I have read endless threads and found all the information that I have been looking for.
Well guys I screwed up. I realized I left the stupid paper clip in when i started the car and adjusted the idle. Thanks Henryd3 for reminding me to take the paperclip out before i started it. I totally missed that. The IAC makes a clicking sound while in diagnostics mode and I think it might be seized up. However i redid the process of IAC/TPS tuning again and this time i removed the paperclip. And so... It worked. Its not running tip top because its had the life beat out of it but I made you a video to show you how it runs now. The video can be viewed on youtube ...
Thanks Henry. When i took the throttle body off and cleaned out all the carbon and assemblies, I seen in a few videos about adjusting the pin inside by turning it. I just felt mine and tried to turn it and it didn't want to move at all. So I cleaned it out and put a shot of penetrating lube on the assembly, let it sit 10 seconds then blew it all out with air. It still didn't turn but i didn't try to force it figuring this model does not turn. I thread sealed with some teflon tape and screwed it back in. I wasn't sure of the sounds so i posted that it was clicking. I appreciate the info and all the help. The cars not dying out now so seems like I have the timing, IAC, and TPS adjusted correctly. I'm OCD as all hell so be sure that the TPS is exactly set at 0.54v. It took some time setting it and getting it to stay when i tightened it down but I got it LOL. its idling in drive at approx 650-675. it says, "650-750 RPM in Drive 283-305 C.I.D. engines with automatic transmission". Should I set it at 750? or leave it?
Took for another ride and died twice. I think it's more involved than what I'm messing with. Prolly a couple of bad fuel injectors. Anyhow. Next week I'm going to start disassembling the top half of the engine and get it ready to come out. It was fun playing with the old stuff and learning from it. I had no idea how TPI worked until I joined here and then started tinkering with it. I'm most likely going to keep the tpi without the air assist because im going to put headers on it. Playing with all the 32 year old components is probably a waste of time anyways. Ill test and check the old injectors to actually see if that was the problem. I read a thread on here about it... just have to find it. Thanks Henry for your support and knowledge. I'll be keeping updates on the build. On a new thread of course. I picked up this Iroc for 1600 bucks. It is rust free, with really nice interior. The dash isnt even cracked. I at least got a good deal with nothing on the actual car being broke. It made the 140 mile trip home no sweat, all highway, so I was impressed.
Any chance the balancer ring has slipped some? Give a bad timing read if so. Might rig up a piston stop for No. one cylinder and check TDC to be sure. Also there is a minimum idle setting on the throttle body that should keep the idle at 400 rpm or so with IAC bottomed out. I'm no fan of the tuned port inj. but I guess we're stuck with it. Usually these injectors start failing and run lean on the highway at a steady cruise or very light acceleration, feel the engine running rough. Or leak through, or spray a lousy pattern. There's are injector testers that will pulse individual injectors, check for fuel pressure drop with ten pulses, give a good idea if they are good, or junk. Handy device.
You can remove the injector clips and ohm the fuel injectors with a multimeter. They should all be about the same reading, mine were all about 16.7 ohms. If you find one extremely low then the coil is probably bad.
Have you checked the fuel pressure? Do you have means of checking the TPS and setting the minimum air? Next time you start it, look at the balancer and see if it's wobbling.
11-22-2017, 06:12 PM
