Yeah that makes sense man. Because on my '75 Firebird, which is a automatic. The idle would read 1000 or so in park. And 700-800 in drive, so I believe you are right where you need to be with it. I doubt it would be much different, although they aren't the same cars. I think that most automatics, operate pretty much at the same idle. Anyway yeah I think you are right on the money. Don't mess with it lol.

Anyway props on getting your Z running correctly. On to the mods bro' hehe

 

I never really thought about it either, but I know J mentioned that the Boost Gauge although not exactly the most accurate is pretty reliable, and my boost gauge when in vaccum sits I'd guess around -5ish or so and that's about where it would sit back before I pulled my manifolds so I'd guess my vacuum is pretty much accurate.

 

Alright, I've been driving my Z. Seems to be doing all good, only one thing I've noticed. Is it just the turbo, or do these cars in general seem to be a bit sluggish when driving on a cold start? It seems like for the first minute or so of driving my car just moves alot slower or sluggish, but it goes pretty good once I hit boost. Then after a few moments the car seems to run quicker, I don't know if maybe it's related to the fact that it runs more rich and the O2 sensor isn't working from a cold start? Does this seem normal?

Went outside, checked my timing and I guess I must have moved the distributor, or the fact that some of the stuff changed since I last set it, but my timing was sitting at like 16-18 before TDC. I advanced it to about 22 before TDC. Oddly the idle when in drive smoothed out a little and actually sits a bit lower now, like even closer to factory spec. So I wonder if that will assist with my issue from a cold start. Also the more retarded it is, the more rich you run right?

 

Don't be in a rush to get going when you first start the car, let it warm up. I think you will notice the car will now run better with the timing at 22*. Just give yourself a few extra minutes when you decide to first start the car and you should not have sluggish cold driving problems....mine sucks to drive if I start it up and just go so I have stopped doing that, i let it warm up for 5 min then I go and I have no problems. Remember, this is an older car and benefits from being warm as most cars do before you drive it...just remember, when you first start it, all the oil is in the pan and needs to get to the top to circulate and lubricate. Just trust me, your car will last longer, drive better and make you happy if you just let it warm up.

 

Mainly it just seems slightly more sluggish, than warm. It's really not un-driveable by any means, I was just wondering if it's normal. It only takes a minute or so.

 

Well, I took the Z to work today with the timing at about 22* before TDC, put my new K&N air filter in, and my god the thing goes. It feels faster than it used to be. It runs alot better when cold now as well. I think the fact that the timing was a bit more retarded than it was supposed to be was making it run even more rich than it already does at cold, and would cause it to bog down. At cold the car runs closer to how it was running warm with the retarded timing, and at warm the thing really goes. Also the odometer just rolled onto 90,000 miles as I pulled in. This engine is ready to go for a good while.

 

Is it normal for the car's idle to raise some as you sit there idling for a while? I took the car in for emissions checking today, and as I was sitting there waiting my turn so they could put my car on the dyno I noticed my idle slowly raised. It didn't keep raising, but it got higher, it went from around normal, up closer to normal, but then if I drive and stop and it generally idles fine, it wasn't until I was sitting there for a while. I don't know if that's necessarily a bad thing or not. I think I'm more or less paranoid. Probably because of the bad experience with my Z31, but on the other hand I did pass emissions.

 

Old car, some idle "breathing" is to be expected unless you've made everything new again. Mine does it, never had a problem.

 

Hmm, a new issues seems to have shown up. The only problem is all of a sudden it seems slightly slower than it was the day before. I'm wondering if a vacuum leak has shown up that I'm missing. I was spraying brake parts cleaner seeing if I could find a leak, nothing. So I don't know, I'll replace some more vacuum lines and see. Ignition timing is fine, I seem to hear some kind of noise right around 2000 RPM, maybe like a slight miss. I don't know. Also does anyone know where I can get a new hose that goes from the air cleaner box to the AFM?


Update: Car is running good again, I wonder if my connectors got something in them and I freed up whatever it was when I was pulling everything apart, testing stuff and putting the connectors back on. I figure I'll have to pull my plugs anyway and check the, I bet they might need to be cleaned off as I'm sure they've gone through a good 100 miles or so with the car running rich.

Edit: I can't tell if the car is running exactly right or if I'm just beginning to expect more than what it can do. The car revs fine and drives fine throughout the driving range, the car will go pretty darn good in boost, and it goes good in vacuum, it just at times feels just a little slower than other times. I don't know if it's me or if the car actually is different.

 

Alright, so I've put that plasti-dip stuff on my AFM boot. I'm letting that dry before I put it back on. Swapped my TPS with the one that came with the car since it would technically have less miles on it. I unplugged the battery to let the ECU reset, changed a few more vacuum lines that were just old, but didn't look broken, and got my self a Fuel Pressure gauge that will work with my car, so I'll check that out.

I also noticed that the tube that goes from the AFM to the Turbo, it was still connected, but the clamp for some reason was real loose and not really even where it was supposed to be. So I'm wondering would a loose clamp or not having a clamp at all be enough to cause an issue or at least be enough to let un-metered air through? I moved the clamp back and tightened it, so once everything is done I'll put this crap all back on and give it a test.

Also got my Vac/Boost gauge today, so I'll have to hook that up. Also I'm thinking about investing in a fuel pressure gauge that I can run inside the car. Any thoughts on that?

 

If the tube going to the turbo from the afm was letting unmetered air to pass then it may cause a slight problem....maybe

A fuel pressure gauge in the car...hmmm I would use brake lines and make sure there are no leaks if you do run it in the car...thats all you need is some gas spraying all over you, the car, your electronics...though it could make for a hot fiery ride, I don't think you want to be known as "FireBall Z"

 

True, yeah I'm planning to do it eventually. Although I'd almost expect it to be like the actual gauge would be under the hood, and then you'd run a wire from that relay to the gauge. Whether that is actually how it works I'm not sure.

Also, I was curious. Even though the Turbo cars don't detect WOT like N/As do, I hear that right at or around 3500 is when these cars start to go into open loop mode. That indicates to me something just like full throttle, right? If so, would it be regardless of throttle position, that it would just start dumping in fuel like an N/A car at WOT? In other words it should be pulling about max fuel pressure at that point, does that sound right?

Update: Swapped my TPS back to the TPS that originally came with the car, and calibrated it per factory service manual. Checked my ECU plugs , unplugged them, sprayed some compressed air, plugged em back in. I covered my AFM boot with that plasti-dip stuff, reset and retightened the clamp that went on the hose from the AFM to the turbo, put in a few new vacuum lines, and my car is back to normal. Boosted right past 3500 again.

 

Well I've encountered a problem, that's not really much of a problem, but still an issue. I found I think a few others with the issue.

Anyway in the past few days I've had this issue with my car starting, the one day it started and then died, and then I started it again, and it got going. Then the other thing I've had happen a few times now is after I've driven the car, and then it sits for a short amount of time and I'll go back and start it. My tach will fluctuate alot, my idle keeps bouncing around and sometimes it will die, if I just give it gas and go, it real quickly evens out and I have no problem. While driving the car runs fine, it's just been these few small issues. I know once in a while I'll have a small problem with the car taking a while to crank over. I checked my fuel pump recently and the pressure and everything seemed to be fine. So I'm wondering if this could be related to the starter or the alternator. If the alternator or the starter is on their way out, would a test reveal whether they're bad or not? I can't link it to what else this might be. The only things that haven't been put on my car that would be new or remanned would be my TPS, Fuel Pump, Alternator, and Starter. Would any of these cause that problem?

 

I've had that same problem come and go with my car since I have owned it. There is not a single Fuel Injection, fuel delivery, fuel supply, ignition, exhaust or emmissions part that hasn't been replaced AT LEAST once during that time...


Good luck.





Rod.

 

Electrical connections... Clean 'em... ALL OF 'EM! All the way from the injector connectors to the ECU plugs.

Go by your local Radio Shack and pick up some electrical contact cleaner.

Be VERY careful. Remember, you're dealing with 25 year old rubber and plastic connectors. Be very careful when you go to pull them apart...

 

After fixing my alternator, I've been driving and it seemed ok, but tonight it seemed like the issue came back. If I hit the brake while driving my headlights dim for a moment, or my headlights still dim along with my gauges with each flash of the blinker. Other times it seems fine, I'm wondering if it's related to a ground or something. Any suggestions on this?

 

Get your alternator tested.

 

Got my alternator tested, checks out ok. So I purchased a new belt and I'll see if that makes any difference. Anyway the problem may be completely different. So I get to Wal-Mart go in, and when I come out I get in my car and put the key in the ingition and it acts like the car is dead. So luckily I have jumper cables, I pop the hood and all of a sudden everything comes on for a moment and then cuts off. So I go and just hit the battery clips a few times to see if that makes anything and then everything starts up again. So I wonder if my battery terminals just have an issue or something. I replaced the clips to the terminals, and I just retightened them the other day, I'll just have to start looking over things I guess.

 

Yeah... make sure both terminals have full contact & no corrosion.

 

It just never ends. I got on the throttle tonight getting on the freeway and I'm back to losing all my top end right around 4000 rpm or somewhere around there. Like the car pulls good, then hits that point and stops. Last time I was hitting a wall at around 3500, and I just messed with my AFM boot, TPS, and really didn't do much, and next thing it was fine again. Any suggestions on this? I think lifegrdude was having this same sort of problem?

 

Got to be those ECU plugs...it's got to be.

 

You know I think you're right. I just went out although 4am, anyway I went out and pulled the ECU plugs, and reconnected them. I go right on past that spot again and everything seems to be good, heck my boost seemed like it was coming on a little earlier even, and I just seemed to have more all around power. So it looks like the last of my engine issues are just down to wiring related issues...oh boy.

So does anyone know or have an idea as to why? Is it just that the ECU plugs have a loose connection, or like a corroded wire somewhere through the car maybe? I don't get how just wiggling the plugs or pulling and reconnecting them makes a difference.

 

Alright from what I can tell it seems the battery cable at the positive terminal has a connection problem, and it's causing my lights to dim, etc. At times I'll let the fuel pump prime, then flip the lights on and the fuel pump will prime again, my clock keeps resetting, and that's probably why my radio turns off alot. Anyway, these kind of issues I think are also the same sort of thing that happens when an alternator is crapping out. Anyway would that be enough to possibly make the car run a little different? Like sometimes it feels fast and other times it doesn't. I'm wondering if it's sort of like the ECU plugs, except it's just a bad connection at the battery affecting everything.

 

A bad terminal connection definately isn't HELPING anything.

 

I pulled it all apart, and man my positive connection terminal was all corroded, and it was loose too, so I sprayed electrical cleaner on it, used a razor blade to scrape everything down, put it all back together, and made sure everything was real tight, and figured I'd unplug my ECU and AFM cables as well and just leave everything to reset. So that should hopefully make a difference.