Disgusted With How My 81 Runs arrrggghhh!

[HammerDown]

Been years and years of rough idle, pinging under load and poor fuel mileage and, it's NEVER been able to run on regular grade gas > > > and it should >WTF it's a low compression, low HP small block Chevy!

I swear at times I'd like to run this thing into a wall > but before I do, I'm going to give it one last chance.
I'm going to remove that POS computer controlled carb and distributor, catalytic converter, egr valve and burn them! ad

Then, I'm going to install a rebuilt pre-computer Quadrjet and a vacuum advance HEI distributor and try that. At least I'll be able to tune the damn thing > like I can with my 600HP BBC Jet Boat.

Years ago I pulled the heads and had new guides, valves, springs done. I installed a new timing chain set too. Compression is good and it's a healthy engine >just idles poor, pings and fuel mileage is like a 632" engine.
Sorry for the vent, just disgusted with a great looking car that has pretty much (by my standards) run like crap for waaaaay to long. :eyerole

 

[spikebot 81]

Your on the right track IMO. One sensor after another failed and then the carb popped and that was it for me. I yanked every emmision control out this car. After installing long tube headers and 2 1/2 duals with new edle carb and new hei dizzy, the engine runs much better. Will even spin the tires. At least I have control of the tune. Not the fred flintstone CCC. Some will disagree but for me I made the right choice and glad I did the swap

 

[damoroso]

Okay, somebodys gonna probably give me some grief for this but, here's something that I've learned about the electric Qjets. They'll run great without all that stuff in them. You can run directly off the primary jets. You'll have to clip the M/C selenoid wires (cause you need the plug to avoid a big hole in the top of the fuel bowl), remove the lean stop and the rest of the associated hardware. The metering rods, plunger etc. The jets the metering rods slide into are screwed into the body of the carb. Unscrew them and replace them with regular jets. I'm running 63's in mine, I'd suggest you start there and maybe even go down to 62's. People didn't believe me when I told them I was going to do this. Transition is seamless, it's super smooth, idles great. I have this carb on a BBC I put in the car, but it's a punched 402 so it's running about 409CID. It has a healthy cam, intake and some head work done, but this carb feeds it well. On a trip of about 350 miles, I got 16 mpg cruising at 81 mph. I have a 2004r trans with a .67 final drive, but a 3:36 rear. In the original configuration, the 350's best was 18mpg. If you need smaller jets still, I'd contact Cliff Ruggles.

This will deffinetly throw a code and set your check engine light, but if you're not going to run the rest of the system, it won't matter. You can simply unplug the computer and leave everything in place. That'll take care of the check engine light too...

 

[HammerDown]

Thanks for the above feedback...not sure I'll unplug the computer as I'm not to sure what else it controls > any dash instrumentation?
I know the computer controls the trany torque converter lock-up on the highway but, I've been told that part of my trany stopped working a looooong time ago anyway. If I pull the computer my trany will properly shift...correct?

damoroso... So you're telling me I can actually reuse my OE computer carb??? If so this would be GREAT!
I'm a little confused how you worded your reply > are you 'not' using the secondary part of the carb???
I do have a pre-computer Quadrajet in rough condition > the throttle shaft clearance is sloppy and will need bushings in the base plate...not to mention a serious rebuild!

I thought about the Edelbrock carb but I want to reuse my OE air-cleaner components. I like where the mixture screws are located on the Edelbrock however > would like to beat the person who located them on the OE Quadrajets > simply a pain to get to!

Question > since the computer controls the OE distributor AND the advance...any reason why I couldn't leave it? Or am I better to just install a pre-computer controlled vacuum advance HEI?
Also >will my original TACH still work?

I'm just not sure what ALL the computer controls yet but I'm about sick of a poor running engine.

Thanks for the feedback.

 

[Peer81]

First I would say, who many degrees has your distributor?
Not saying that is isn't your carb but it's logical to point to the divise that needs the most study to handle.

On your E4ME, if you disconnect the ECM the solenoid will not be energized so the primarie rods will be in full rich all the time in the jets. If your A/F solenoid doesn't work the same thing, could also be the problem that you have right now.

I don't know if the ECM adjusts the distributor to TPS degrees? But if you want to ditch the carb I would also change the distributor. As far as I know the ECM has a fixed control for the distributor and with a vacuum distributor you can always change the springs and weights etc etc.

If I understand Damoroso correctly he has cleaned the inside of the carb. But he uses the 81 spring loaded rods that are placed into the pre ecm jets correct? Because normally a pre ECM carb has a powerpiston with a spring to pull the rods up or down according to engine vacuum. I'm very curious how it works.

At this moment I'm also struggling with my E4ME but my believe is that the stupid thing should work. Changing it is no options. But reading through the tech carb books made me realize that the E4ME carb is perfect to controll to get the carb to work perfect. And I still have that idea after two years assembling and disassembling the carb... :W

Greetings Peter

 

[damoroso]

On the 81, the ECM controls a few things. The carb being the most effected. It also controls the EGR system, the converter lock up and the distributor advance. On the dash, the only thing the ECM controls is the Check Engine light. Like I said, if you disconnect the carb, or do the mods I'm talking about, you'll get a steady Check Engine light set, which makes sense. Then again, if you go with any carb other than the E4ME, you'll get the same thing. When the system works properly, it's great. The problem is, as the cars get older, it gets more and more challanging to keep the system working. The more mods you do to gain more power, the more challanging it gets, not so much to keep the system working, but to keep it from throwing faults and setting the light.

I'd also suggest, if you're going to change the carb, you change the distributor too. Run an HEI with a vacuum advance on it and you'll be good.

Mine would set the light at an idle, but it'd clear after driving about a block. It'd run great as long as the choke was closed just the slightest bit too. My issue was I couldn't get rid of a lean miss no matter what I did. Made me crazy!! Especially since crusing under about 50 I'd still have it 'cause it would quite be in the mid circuit.

I'm not running any primary metering rods in my carb and I am using the secondary side as normal. No power piston, springs or anything, straight off the jets. I have done some modifications to the carb, (I modified the idle tubes, the mixture screws, the secondary rods and cam and the air valve on the secondarys) but that's because the engine has a different cam, intake, comp ratio, and a bunch of head work. And it's a BBC.

On a stock or slightly modified SB, running off jets should be fine. The only challange I can see is getting the proper size jets in it.

 

[HammerDown]

On the 81, the ECM controls a few things. The carb being the most effected. It also controls the EGR system, the converter lock up and the distributor advance. On the dash, the only thing the ECM controls is the Check Engine light. Like I said, if you disconnect the carb, or do the mods I'm talking about, you'll get a steady Check Engine light set, which makes sense. Then again, if you go with any carb other than the E4ME, you'll get the same thing. When the system works properly, it's great. The problem is, as the cars get older, it gets more and more challanging to keep the system working. The more mods you do to gain more power, the more challanging it gets, not so much to keep the system working, but to keep it from throwing faults and setting the light.

I'd also suggest, if you're going to change the carb, you change the distributor too. Run an HEI with a vacuum advance on it and you'll be good.

Mine would set the light at an idle, but it'd clear after driving about a block. It'd run great as long as the choke was closed just the slightest bit too. My issue was I couldn't get rid of a lean miss no matter what I did. Made me crazy!! Especially since crusing under about 50 I'd still have it 'cause it would quite be in the mid circuit.

I'm not running any primary metering rods in my carb and I am using the secondary side as normal. No power piston, springs or anything, straight off the jets. I have done some modifications to the carb, (I modified the idle tubes, the mixture screws, the secondary rods and cam and the air valve on the secondarys) but that's because the engine has a different cam, intake, comp ratio, and a bunch of head work. And it's a BBC.

On a stock or slightly modified SB, running off jets should be fine. The only challange I can see is getting the proper size jets in it.

Again, thanks for the information...I know the Holley 4150 DP/vac-sec like the back of my hand however, never entered a Quadrajet. >so I'll have to see where these 'new' primary side 62/63 jets will sit.
Plans are to replace my dizzy with a regular GM vacuum advance HEI unit.
For the simple reason of cable hookup I would like to give your idea of reusing my OE carb > > > I'll have to get acquainted with the insides and may have to get back to you a few times for further direction.
Not worried about TQ lock-up on the highway as I'm told that part of the tranny quit a long time ago.
Blocking-off the EGR, removing the air pump are also in the plans, along with removing the (I'm sure clogged-up) catalytic converter.

Looking forward to having a good idling/running small block

 

[Peer81]

I would say, if you're going that route. Try to find a normal Q-jet and put that on your engine. More points to adjust the carb so more control on the air fuel ratio in all different ways.

Greetings Peter

 

[damoroso]

I would say, if you're going that route. Try to find a normal Q-jet and put that on your engine. More points to adjust the carb so more control on the air fuel ratio in all different ways.

Greetings Peter

I here you Peter, but a replacement carb is $400 + in cost compared to using the carb he already has...I'd suggest using the oringinal...

 

[HammerDown]

Did some sniffing around on eBay, found a re-builder in Florida that ONLY deals with Quadrajet's > computer and non-computer carbs.
ROCHESTER QUADRAJET CARBURETOR CHEVY 305 350 M4MC 4 BBL - eBay (item 160509596939 end time Dec-21-10 15:42:08 PST)

$230.00 would get me a fully rebuilt, surfaced baseplate etc and jetted to my 350's requirements. With a warranty.
I did ask them about modifying my OE computer carb to run on my engine without the computers input > > > WOW, did they scare me away from that idea!:ugh
Pretty much said way too much had too be done to it and labor charges would be higher vs just bolting on their rebuilt non-computer Quadrajet.

My head hurts > think I'll buy the regular HEI first

 

[damoroso]

Sorry they scared you. I put another 300 miles on my car between yesterday and today. If you were closer, I'd have you over, pull your carb, make the changes (in about 5 minutes with it on the bench) and wouldn't charge you a thing. I'm curious about the builder in Florida, I talked to one such builder when I was looking for jets. They said since the rarely replace them they don't stock them. Nice. How do you tune a carb without jets? Do they even pin check them to make sure they're accurate? What else don't they do.

Before you buy, do yourself a favor. Call Cliff Ruggles and have a conversation with him. Tell him about these posts and see what he says. He and Lars are both reputable, honest and very, very knowledgeable about thest things. Here's Cliff's contact info. Cliffs High Performance Quadrajets :: Qjet Carburetor Rebuild Kits, Parts, Quadrajet Rebuilding, Quadrajet Parts, Bushing Kits, Carb Tuning

 

[Peer81]

I agree, Cliff and Lars are the people

Greetings Peter

 

[HammerDown]

Sorry they scared you. I put another 300 miles on my car between yesterday and today. If you were closer, I'd have you over, pull your carb, make the changes (in about 5 minutes with it on the bench) and wouldn't charge you a thing. I'm curious about the builder in Florida, I talked to one such builder when I was looking for jets. They said since the rarely replace them they don't stock them. Nice. How do you tune a carb without jets? Do they even pin check them to make sure they're accurate? What else don't they do.

Before you buy, do yourself a favor. Call Cliff Ruggles and have a conversation with him. Tell him about these posts and see what he says. He and Lars are both reputable, honest and very, very knowledgeable about thest things. Here's Cliff's contact info. Cliffs High Performance Quadrajets :: Qjet Carburetor Rebuild Kits, Parts, Quadrajet Rebuilding, Quadrajet Parts, Bushing Kits, Carb Tuning

Thanks for the above link and info...please understand, I didn't call that Florida carb rebuilder to confirm your prior information but, to see if they had any other tricks when performing the switchover work.
They just said sooooo many things had to be modified and blocked to make it work,:ugh...most people just opt for their rebuilt non-computer Quad. The woman I spoke to also mentioned a LOT of people have done what I want to do.
I've also been on YouTube looking at some videos about the E4ME >just in case I decide to get inside it myself. It would be great (if) there was a detailed video available to watch and learn from.

I'll give Cliffs a call Monday...and thanks again.

 

[HammerDown]

Now that the Holidays are over...it's time to get back on track with making my 81 run good.

 

[Peer81]

Keep us updated!

Greetings Peter

 

[HammerDown]

Update...of sorts
Few weeks back I did speak with Cliff's Performance Carbs...one thing's for sure > (if needed) he's too busy to even work on my carb until the end of next summer! Very knowledgeable fellow and to my surprise is ALL FOR the E4ME.
He feels my problem is a LEAN issue and from my test below I tend to agree. He strongly suggested one of his rebuild kits and to preform two internal adjustments from 3 screws (fattening up the mixture) to make it 110%

Here's my delima, even if I do the above, it doesn't give me what I originally wanted, which is a engine I can tune myself and remove all the emissions BS. And > get it to hopefully run good on regular grade gas vs premium
Even if I do the above...I could very well later be chasing other old/failed computer controlled items on the carb and around the engine.
Soooooo which way do I go ???

Also...just today I was able to reconnect the battery and take it for a drive. Been dealing with snow storm after snow storm here.

I jumped the two prongs and with the key in the 'run' position it started to blink out 1-2 (12) dozens of times > well over 4 times.
It never gave out any 'codes' other than the 1-2 (12) over and over.
So, then I removed the air cleaner assembly and proceeded to carefully spray starting-fluid to find any vacuum leaks. When the carb got a direct slight whiff, the RPM raised-up and smoothed out nicely. This told me the engine was infact needing fuel and running lean. (if) it would have dropped RPM that would have indicated a rich mixture.

Carefully spraying first around the intake manifold showed no change...then, I started to spray the vacuum lines, vacuum junctions and T's fittings around the carb.
Now, I'm not sure (if) I had busted it off or it was already cracked and the slightest touch busted it all the way off but...the front lower center of the carb is a 3-way vacuum T consisting of two larger ports and one smaller port > the smaller port was hanging by a thread.

As soon as I removed that 3-way T and taped the main port interning the carb the engine idled smoothly and the starting fluid test dropped RPM!

So, I'll replace that busted T and test it again.

Question...years back I did the code test that one time gave me a bad 02 sensor and another time that gave me a part ontop and in the carb, something with wires coming out of it > I don't remember what that part was called?
However, if there are no codes, would the computer just repeat the 1-2 blinking over and over???

Thanks for any further feedback, Ray

 

[Peer81]

Hello Ray,

From me nothing but good words for Cliff and his company!
For the carb. I think you need to do some wider research on how much emissions junk you can remove savely before it affects the carb or ecm. I don't know. At this piont I'm running with everything on it except the airpomp has no internals anymore.

I think Cliff also told you, you can adjust right about everything on an E4ME if you just know the carb inside out (and that isn't a big problem if you take the time).

The best way to see if you have any vacuumleaks in the vacuumlines is to disconnect the source at the intake vacuumport (behind the carb). The you shut don't almost all the vacuumlines (except for the brakebooster). And you can hear or see (on a vacuummeter) the difference.

The item on top of the carb could be the A/F solenoid which is sitting inside the carb but with the connector on top of the carb.

Greetings Peter

 

[damoroso]

Ray, I thought I read that you "reconnected" the battery? Disconnecting the battery will clear the codes out of the computer. If that's the case, your going to have start over with finding the codes. Drive the car for a bit and try to pull the codes before you disconnect the battery again. Let us know what codes you get.

 

[HammerDown]

Ray, I thought I read that you "reconnected" the battery? Disconnecting the battery will clear the codes out of the computer. If that's the case, your going to have start over with finding the codes. Drive the car for a bit and try to pull the codes before you disconnect the battery again. Let us know what codes you get.

Sorry I wasn't more clear...I'm aware a battery disconnect clears any codes. After reconnecting the battery I did take the car for a substantial drive. Upon returning home, I then checked for codes...nothing came up.

After I replace the busted vacuum-T I'll take it out for a drive again, and once again check for codes when I get back.
Thanks, Ray

 

[HammerDown]

Well, I hoped by replacing the cracked vacuum T and the other few 'questionable' vacuum lines I would fix or help the rough idle.
No so lucky...now questioning (if) I should spend the money for one of Cliff's rebuild kits or, just remove and replace the OE dizzy and carb for non computer controlled parts.
It amazes me that with the rough idle I have, it's not throwing a code...I can tell by the slightest whiff of starting fluid, the engine raises RPM and smooths out > but is this infact internal carb related???
However, off-idle appears to be running fine.