Marucci714

Hello all,


First post here, love this website, have found and fixed many issues thanks to your guy's vast knowledge about these cars. Appreciated!


I have an 86 Camaro(H), swapped 350 Goodwrench 290hp/350tq with computer controlled 4Bbl QJet, Hooker headers with 3" catback. Timing at 10* BTDC idle - 32*BTDC Vacuum advanced


Car runs rich at idle and while driving per my AFR(narrowband) Gauge. I've pulled the plug and also indicates a rich mixture. Carb was purchased reman/rebuilt about a year ago.


I've messed with a vacuum gauge and the idle mixture screws with not much change. 1st 2nd and 3rd gear all drive and pull great, but once you jump on the freeway and hit 4th and 5th gear its like all power is gone, doesn't stumble, and holds a consistent 65 mph, but feels like S***. Yes I know 5th gear is OD or whatever so it won't pull like the others, But it shouldn't feel the way it does. My feeling is the carb isn't getting the proper re-fuel for the high load, but my AFR gauge tells me otherwise(Rich). Im not really sure what to think here, besides the carb needing obvious tuning, timing being off, or fuel pressure? Why would it drive great in low gears and like crap in 4th and 5th? I've read to take the fuel filter out and put an in-line one in. My only description of the Bog/power loss is the motor chugging? It doesn't stumble, it doesn't feel like its going to die, but you hit the gas and it just barely picks up speed.


Any advice would be greatly appreciated, im not an expert car builder, this is not a restomod, just wanted a fun car to drive and learn on that I wouldn't be too upset with if I effed it up lol. I've learned a lot, put a gajillion hours into reading and researching, and don't plan on giving up anytime soon.

Damon

Oh, boy. I'm not sure where to jump into this pool....

OK, first off, it's none of those things you think it might be. Sorry, but it's not.

This is a tuning/ignition timing curve issue, if I had to guess.

Low end torque on that GMPP 350/290 motor is in short supply. Too much cam, too little compression. It's not going to pull worth a damn below about 2500-3000 RPMs. You can crutch it to some extent with ignition timing and tuning changes, but it's just weak down low no matter how you slice it.

You gave your initial/total timing, but what kind of curve do you have on that and how much vacuum advance? Let's start there.

Marucci714

It's 290/350 not 350/290 if that makes any difference. I realize it's not the cream of the crop or even close to it, but it beats the barely running 305 it had and it's not a track car so I'm not looking to make huge numbers.

You know, those are 2 good questions, I used the Mallory I think it is that came off the 305. Never thought to check curve and not exactly sure how to measure the vacuum advance? So what you might be getting at is my curve could be too fast/vacuum advance too high for my low compression engine resulting in too much advance, thus poor performance?

jwfirebird

iTrader: (2)

it sounds like timing to me too, if its an aftermarket mallory should have adjustments. probably going to like somewhere in the mid teens for initial and then set the adjustments for all in.

Marucci714

Thanks for the post JW I appreciate your guys' input. I double checked my timing again, I set the overall to 32* and my initial ended up at 14*BTDC. Im guessing that means my current curve is 18*? Full advance comes at about 3-3500 rpms when im revving it, does that sound about right?


My only thing is, if it were my timing, wouldn't my car also drive like s*** in 1st 2nd and 3rd gear? Because those 3 gears drive fantastic like I said before, the torque is there and it gets up and goes no problem. But once you hit 4th it feels like a fuel starvation thing... Would my timing, where I have said the initial is at 14* and overall 32*, make my car run as rich as it is as well? When im at a light and in neutral, and I try to rev it up a little, sounds like its sucking in a bunch of air and doesn't rev up right, but if I bump the gas pedal a couple of times hard to rev it, it will rev right after about the 3rd bump of the pedal.

jwfirebird

iTrader: (2)

you will have to tune the initial to where it idles and performs good and if thats too much total adjust that, all depends what dist you have

Marucci714

Ok got it. I was thinking about taking the total down some too and seeing what changes I get.


I also have an A1Cardone Computer Controlled Dizzy that I never put in and don't really want to, but I was thinking about throwing that in there and seeing what it does since it has no mechanical advance or anything that needs to be changed/adjusted(besides initial timing) and seeing what my car does since the ECM will tell it what to do.

naf

iTrader: (7)

The computer controlled carb and dist are a matched pair. Running the ccc - qjet with a mech dist is going to put the ecm into limp mode, full rich. The ecm needs the reference signal from the dist.

Go all mech or go back. Although the ccc - qjet can be modified to work like a mechanical carb, I wouldn't recommend that as an optimum solution.

Marucci714

Thank you naf!!!! Then I guess I know what I am going to do now. I didn't realize it put it into limp mode which would explain my rich condition, and since I have the emissions(nazifornia) and ccc qjet hooked up I will put that dizzy in and see what results I get. With the Mallory I have in it, the check engine light comes on but only throws code 12 which from what I understand is "operating normally" which its not..


And now that I think about it, that is what 4th and 5th gear are feeling like, limping/chugging, but only in those 2 gears.


Again I really appreciate all of your guys' input. I will report back when I get that done this weekend.

naf

iTrader: (7)

Try the stock dist and set your idle mixture screws back to original position. If unknown, set them to 4 turns out.

With the wrong dist the cel should light and it should also display the EST trouble code.

If it's been running rich you'll want to pull your plugs and check them. Likely need to be cleaned and/or replaced. A rich condition will not only bog the motor down but can foul plugs resulting in misfire, especially when cylinder pressures are highest.

Why was the stock dist replaced? Was there an issue previously?

Marucci714

I will throw that ccc dizzy in there(brand new) and my mixture screws are both currently about 2-1/2 turns out which I will re-check.


The cel does come on every time I turn the car on, BUT, when I run diagnostics with a paperclip, it flashes me code 12 over and over and over and over and never stops flashing 12 until I just shut her down.


The plugs are rich and smell like gas and I just bought brand new plugs, just haven't swapped them yet which I will do so.


I personally never replaced the stock dizzy, it never had the stock one since I've bought the car for cheap, it already had the Mallory in there with a 305 and ran poorly. I knew I was going to swap motors, so didn't care at the time and it had the T5 already in there so I was happy I wasn't going to have to swap/convert that too with the motor. (Eventually I will swap the T5 to a T56)


I decided to buy the A1 Cardone ccc dizzy a while ago, I've just never put it in there thus far thinking I would get better results with the Vacuum/mechanical advance but apparently only partial sub-par results thus far.

Damon

Didn't realize you were using the CC-QJet with a non-CC HEI distributor. Like naf said, that's a no-no. No mixie-matchie. Both computer controlled or both non-computer controlled.

Ozz1967

iTrader: (4)

Put the stock or the newer dizzy in, it doesn't matter. You disconnect the EST wire or take out the ECm fuse and set timing to 6-8* BTDC, mine is happiest at 7 or 8. Turnthe car off, put the ECM fuse back in or reconnect the EST cable and you're done. The computer controlls the timing from there on out.

Does the carb "click" when you turn the ignition to run without starting the car? It should click constantly for 30 seconds or so once the ignition is turned to "run".

Marucci714

I got the cc dizzy in, didn't have my timing light on hand so used my vacuum gauge and got it running good with the EST disconnected. Turned it off, plugged the EST in , it tried to start then would just die everytime. Finally it started and ran rough for a couple secs then died again. Gonna grab my timing light and see where I'm at and try again. I unplugged the batt for a while, so the ECm should have reset correct? Or is there another way i have to get it out of limp mode if it was in it?

Yea the solenoid on the carb clicks for 30 secs or until I start it.

Ozz1967

iTrader: (4)

The car runs in limp mode with the EST disconnected. No timing advance, no fuel mixture adjustment, just like crap. If it dies almost immediatly, definitely check the base timing but make sure you didn't knock anything else loose either.

Damon

Setting base timing with a CC-HEI by disconnecting the timing plug or jumpering the ALDL you are NOT NOT NOT looking for best vacuum reading under those conditions. It will be WAY over-advanced when you reconnect the ECM-supplied timing if you do it that way. The base timing with the ECM advance removed the motor will barely run. But plug everything back in and voila! she idles like a champ.

Beg borrow or steal a timing light.

Marucci714

I have a timing light just left it at my pops house. Grabbed it today turned the timing down, reconnected the EST, and like you said voila! Drove her around a bit and noticed the 2 wire solenoid on the carb (mixture solenoid?) never stopped clicking like it used to(it would stop after 30 secs). It just kept on clicking until I shut her down. Ran diagnostics and pulled codes 15, 23, & 32. Gonna look em up and hopefully proceed. Just happy I can pull codes now cuz I knew something wasnt right, just didn't know what. Praying its nothing crazy, but won't get my hopes up...

Ozz1967

iTrader: (4)

I've never experienced one that never stopped clicking. They ususally either click like they're supposed to, or they don't click.

there used to be a link here on the site that had a whole bunch of codes but since the web site made some changes some of the old links vanished.


Also, double check your ECM fuse. I I pull the EST wire on my car without disconnecting the battery first, it blows the ECM fuse when I reconnect it.

Marucci714

Yea it was really strange, its never done that before. I unplugged it while it was running and it stopped, plugged it back in and kept clicking. I'll check ecm fuse like you said.

jwfirebird

iTrader: (2)

most all our laws are similar to CA. all they do on emissions here 95 and earlier is visually check and see if its got cats, no light and sometimes a guy will pop the hood and quickly look at whats under there. he wouldnt notice if it was a mallory and non cc carb, with all the emissions crap plugged. i went that way for a while. but after 25 years its safety only, i asked the one time about what exhaust and stuff and he said you are on your own, if nothing is falling off we dont care if it even has one. its between you and the cops he said, lol.

jwfirebird

iTrader: (2)

unless you live in NYC then they do the sniffer i believe to a certain point.

naf

iTrader: (7)

It quit clicking before because the ECM never received the reference signal from the dist and 'assumed' the motor had never started. Once it quit clicking the primary mixture needles stayed in the 'up' position allowing the motor to be flooded with extra fuel.

Because the ECM didn't know the motor was running, it never popped any trouble codes before now. One of yours is most certainly the EST code that trips when the motor is run with the four wire EST cable disconnected from the dist. Reset the ECM by unplugging it (single wire lead from batt post should have a connector about a foot down the inner fenderwell.)

With a different motor under your system you'll certainly need to adjust dwell for the ccc-qjet. This requires either an old fashioned dwell meter or a scanner that will read real-time data from an ALDL port. The intent is to set the mixture range for the mixture control solenoid using the IAB adjustment and/or the idle mixture screws.

naf

iTrader: (7)

It shouldn't do that.

Marucci714

JW - They do the full blown visual and sniffer here in CA if you are Pre OBDII. I mean I have a guy that can pass it for me which I did, but it would much more convenient if it would pass on it own. and cheaper lol.. If OBDII they just check for codes and send you off.


naf - so its ok that my MC solenoid continues to click while the motor is running? From what I hear if it clicks its still good. Im not exactly sure what dwell is or what the change affects will be? I need to change it since I went from a 305 to a 350? Is there a 'scanner' capable of making the change on top of reading the dwell? Any references to a scanner and software that I can do this with? I noticed I am still running rich( just a touch less rich than when I was in 'limp mode', not much) I need to adjust the mixture screws again, but still need some help tuning this thing up. I don't have the Air temp sensor in the snorkel air cleaner hooked back up yet, but plan on doing so, I hear this also affects (somewhat) how the MC solenoid mixes A/F.

Marucci714

I bought a meter that reads dwell and rpm and all that other stuff. I've read some and watched some stuff but could a walk through on how to accurately get a reading. Do I use the 6cyl setting for my 350 to read from 0-60* or 8cyl to read from 0-45*? Warm up car, un plug sensor and complete the circuit with the probes to get the reading via the connector/pigtail? What degree means what and where should I be at?

Ozz1967

iTrader: (4)

Nothing gets disconnected. You take the green plug that's sitting free in the harness near the AC/heater blower and put the alligator clip on it from your dwell meter. Ground the other side. Use the 6 Cyl and your goal is 30*. Now, when the motor is running, it should bounce to either side as the O2 sensor reads the exhaust and the ecm hunts for the correct mixture. If it's High or low, or pegged, you need to adjust the IAB on the top of the carb in 1/4 turn increments until you get it in, providing everything else is set properly.

Ozz1967

iTrader: (4)

The clicking should stop after 30 seconds or so.

Everything needs to be hooked up for the system to work right. O2 sensor, MCS connector on the carb. TPS connector on the carb. ECM working.


The four turn rule should get you close enough to tune the IAB with the dwell meter. The IAB is the "fine tune" and if the rest of the system isn't close, then it won't be able to tune enough to bring it withing range.

Ozz1967

iTrader: (4)

You're probably right, but it does. I don't know for sure if it's when I first disconnect it or try and plug it back in. I just know that the fuse is blown after setting timing. So I alleviate that by using the ECM fuse as an alternative to the ALDL or EST wire.

naf

iTrader: (7)

The mcs should continue to click as long as the car is running. If the key is turned to run it will start clicking. If the ecm does not receive a reference signal within half a minute or so it will stop because the ecm assumes the motor has not been started.

The mcs clicks 10 times a second. The clicking is the electro - magnet pulling the plunger down and forcing the metering rods into the jets, restricting fuel. Dwell is the measurement, in percentage, of the time the rods are down.

Marucci714

ok here is the issue, as you all may have experienced, previous owner wiring harness hack job. I tore the AC/heater out along with its hacked up wiring, and I did clean up some wiring that was melted and/or cut. How else can I get a reading on my dwell. Should I splice a clip into the line?


Ozz- Everything is plugged in, and to my knowledge is working. O2, TPS, MCS, dizzy, and ecm must work as I just pulled codes off it, unless that is not an indicator of a bad ecm.


Where exactly is this IAB screw that needs to be turned in 1/4 turn increments? I know you said top of the carb, but... lol pics possibly?

naf

iTrader: (7)

The dwell diagnostic lead is part of the engine controls harness, which comes out of the pass side fender. Splicing into the mcs lead reportedly provides an inverse reading.

The IAB set screw is in the center of the carb directly in front of the choke blade. It is covered by a tamper proof cover from the factory.

Marucci714

ok, I know exactly where you are saying the IAB is, and I think since my was rebuilt/raman, IIRC there is a screw that opens mine up. i'll have to re-check that when I get home from work.


I will check for the diagnostic lead(if im understanding correctly should already be on the MCS wiring) but if its not there, then I don't know where im supposed to measure. Like I said, I will verify when I get home. Thank you again naf/ozz/damon/jw, you guys are legit for helping me out. I seriously appreciate the help you have been providing me.

Marucci714

I was correct, my IAB has no tamper proof cover it's right there on top easy access.

Problem though, they did cut the diagnostic lead out. I cut the old butt connector out and tried getting a reading, but I don't think it's accurate. Was stuck at 19, I touched the IAB a little and it finally took my afr gauge out of rich finally but started jumping back and forth.

How can i get an accurate reading without that diagnostic lead?

naf

iTrader: (7)

Stuck at 19 is normal for a system out of adjustment.

Try setting the idle mixture screws at 4 turns out and, with the engine warm, go thru the full range of the IAB a quarter turn at a time from 2 turns out until the dwell reading starts to move. If no luck, repeat the process with idle mixture screws 2 turns out, then 2-1/2 turns out...

You want a good dwell that varies around +/- 10 degrees or so of 50% or 30 degrees on the 6 cyl scale. It will vary as the ecm continues to adjust for O2 readings.

Before any of this ensure your tps voltage is around 0.4 volts at idle. You can back probe the top and middle leads with it plugged in. Timing and plugs, wires, cap and rotor should all be known good as well as no vacuum leaks. I usually set dwell on a new motor with all vacuum ports plugged, get it good then reconnect each vacuum line noting if any cause a change indicating a leak.

If you're not certain your cts is good you can short the leads to confuse the ecm into seeing 'full hot'.

A good scanner can show you all of this data in real time if you can find, borrow one.

Marucci714

Sorry guys it's been a while, crazy past couple of weeks at work. I got some rewiring done, fixed the cts and the vacuum sensor.
Checked my tps voltage at KOEO, and was at 1.8V
Wow, that was way off, spent a week trying to find the right 2.5mm nut driver which I finally found. Adjusted it down to .40V and then the engine started idling erratically, hunting for a steady idle which used to idle perfect before at 750-800 (manual trans) no "hunting/searching" for steady idle.
Thought maybe it was my mcs was still out of adjustment. Did my idle mixture screws both at 3 turns out, checked dwell and adjusted from about 50 down to avg. of 30 degrees. Now she really runs like ****... will randomly just die at idle, thought I fixed it and went for a test run and died before I got to the end of the street.... effing A! I'm so frustrated at this point... what am I doing incorrectly or missing...

Ozz1967

iTrader: (4)

All of your vacuum lines on the carb are capped right when you do this right?

Put idle mixture at 4 turns out from seated. When you adjust your dwell, you're adjusting the IAB (big screw) on the air horn in 1/4 turns down to 30 degrees on the 6-cyl scale. You adjust it, wait for 30 seconds to a minute, get the reading, then adjust again.

Have you touched the lean/rich stops at all?

Marucci714

No, I didn't have the vacuum lines capped off... shoot now that I think about it Naf said he does that, and the Chilton says only to unplug the purge solenoid, which I didn't remember to do....




Yes sir, when adjusting dwell im adjusting the IAB (big screw) right in front of the choke plate highest part on the carb I believe.


No, im not exactly sure what/where the lean/rich stops are?


I did however purchase an AutoXray Ezscan AX6000 yesterday so that I can read the live data on the scanner instead of hoping my readings are accurate on my Meter

Ozz1967

iTrader: (4)

Cap off ALL vacuum lines going from the carb except maybe the brake booster line. This will eliminate any possible vacuum leaks that you may have and will get you the truest setting you can get while you tune the IAB.

Marucci714

Understood, I will cap off all vacuum lines and try again and report back.