Has anyone reading this done it before on the 4.9? I am not sure how to go about advancing the timing on the 4.9, it looks way more complicated than advancing the timing on a civic. So how do I do it?

Thanks.

I have done it to mine, it is just like advancing the timing on any car....

... basically, the timing is all conputer controlled, but you can manually adjust it, which means the computer still "thinks" it is like normal, but in reality it is advanced 3-4 degrees (I assume you are talking about the advance timing trick on the 4.9?) which which case you just use a timing gun and adjust the distrubtor so that it is advanced/retarted to how you want, then tighten it back down.... the computer will still make it's corrections, but you have manually (in my case) advanced the timing 3 degrees....

Hope this helps, if not, feel free to let us know :)

no, don't just do that above. you have to find the aldl box. it's under the dash, just to the left of the steering wheel. it has a little cover on it. when you take the cover off, you find about 12 pins. use a jumper wire, when the car is off, and jumper the top most left pins (top left and 2nd to left) together. start the car and now the display should say "set timing mode". now go under the hood and find he distributor hold down nut. it's a 15mm nut. you'll probably have to remove part of the air cleaner assy.

hook your timing light up like normal. point the timing light at the water pump tabs. loosen the distributor hold down nut and twist the dist in advanced direction. the timing tabs go in increments of 4... the first tab being 0 twist dist until you have about 13 or 14*. 13 works best for me. tighten the nut back down, replace air cleaner assy and drive, checking for a pinging spark knock sound. remember that you ALWAYS have to use 93 now.

ok, sorry I forgot to mention about the ADL thing, he is correct, and that is the right way to do it....

...although when I jumped mine, the car would set the timing to 10* BTDC, factory prest, and do all that, but never once was I able to get it to display "set timing mode" or does it only say that on '94+ DeVille and not '91-'93? the car didn't show any special code or anything when i jumped it, but it was obvious the engine timing was set back to factory preset (idel dipped lower etc...)

it displays that on my 91 sev. when the car is off, jumper the pins. now crank the car and it should say that on the display... maybe not on the devilles?

my 94 went to "set timing mode"

also be sure to clean the crank pully off really good and find the notch it it thats on the engine side of the pulley , mark it with chalk or something white . then clean off the waterpump tab very well so you can read and understand the incraments it goes in (ie its marked as 8-12-16 or something)

no, don't just do that above. you have to find the aldl box. it's under the dash, just to the left of the steering wheel. it has a little cover on it. when you take the cover off, you find about 12 pins. use a jumper wire, when the car is off, and jumper the top most left pins (top left and 2nd to left) together. start the car and now the display should say "set timing mode". now go under the hood and find he distributor hold down nut. it's a 15mm nut. you'll probably have to remove part of the air cleaner assy.

hook your timing light up like normal. point the timing light at the water pump tabs. loosen the distributor hold down nut and twist the dist in advanced direction. the timing tabs go in increments of 4... the first tab being 0 twist dist until you have about 13 or 14*. 13 works best for me. tighten the nut back down, replace air cleaner assy and drive, checking for a pinging spark knock sound. remember that you ALWAYS have to use 93 now.

im not sure if you made a mistake but im pretty sure its the top 2 right connectors side by side not the top left, i did the top right 2 on my 93 eldorado and the "set timing mode" came up, thats probably his issue also with mine i cant read the timing tab but what are the incriments? right now the car says 10* at the tube on the timing tab. not sure if thats right but i doubt it.

according to alldata its incraments are 0-4-8-16-20

Thanks for all the info yall.

Remember, your Deville has no alphanumeric display. The Eldo, and the later Deville do.

so is 20 where the tube is or would 20 be like 24 as in the next numerical number?

I think the static timing tube is the other direction After tdc

BTDC 20^16^8^4^0-O <-tube

:bouncy: :bouncy: :bouncy:

so is 20 where the tube is or would 20 be like 24 as in the next numerical number?

no, the tube is below 0, the first tab, on the bottom, is 0, next point on tab is 4, 8, 12, 16, 20.

and yes, i was wrong, it's the top right...

I have a question to add to this being a newb - how will you know what the right timing is? I mean how do you determine the right timing using the light and the procedure?

Also - if your ALDL connector still has the grey cover, it has a jumper moulded inside the connector - use that!

i didn't know it had one in it!! i'm not sure I understand what you mean "how do you know the timing is right? You hook everything up, point the timing light at the water pump and there'll be a mark on the flywheels that'll line up with one (or close) one of the triangles. you'll just have to do it, then you'll see. rotate the dist until you get 8* (if you want to use 87 or 91), 10* (cadillac std, use 91-93), or 13* (ALWAYS use 93)

2d a newb ? been here as long as me ......

2d a newb ? been here as long as me ......
lol not that way Stoneage, you and I are vets ;)

I was saying I'm as newb when it comes to ignition timing. I still do not understand it's purpose, why it needs to be advanced/retarded, etc.

it sends juice to the spark plug at exactly the right time. When you advance it, it fires "sooner". maybe a little before TDC on the cylinder. retarding it makes is fire "later" or "slower" . it's complicated why it's different for premium and regular octance.

whew, that is one piss poor analogy...

I have a question to add to this being a newb - how will you know what the right timing is? I mean how do you determine the right timing using the light and the procedure?



I just advance mine until I hear it barely ping when the engine is at high load and low rpm's. This is the point where you get the best power and best fuel economy.

"I still do not understand it's purpose, why it needs to be advanced/retarded, etc."

as bbob has said the timing on the 4.x pushrod engines was very soft(retarded) to let you use lower grade fuels in a pinch . Advanceing the timing removes this feature and you get the most out of your premium fuel (maybe 3 hp?) the power isnt enough to notice in a 2 ton car but youll get good gas milage ie poss .7-1.0 mpg (sorry cant convert to litres)

in my case it did indeed remove the "hot in traffic off idle missfire"

how much did you guys advance your timing? I'm running 13* (give or take a little cuz it bounces some) but last night that thing sounded like it was going to ping and rattle itself to death. i drove 65 in 3rd all the way home so it wouldn't do it. i'm going back to 10* to see if that helps. i'm assuming that metallicy pinging rattly sound is indeed spark knock.

would a bad egr valve cause this condition all the time, or what else could? I thought i could safely get 13* outta it, but maybe with the mods (bigger injectors or something) something isn't the same?

13 deg here , no noise in the florida heat and traffic (gridlocked for 30 minutes in 95 deg air)

in fact she runs much beatter in traffic now . this thing really acts like its a new car

EGR may be hurting you , but check to make sure where you put it's timing is right , i had to figure it out as 13 is not marked and each marked incrmeant isnt marked in any kind of mathmatical order . sounds like its parked at 14-15 to me

yeh i thought that too. to manual clearly says that the top of the first "triangle" is 0, and the top of the next is 4, and so on. I've got it on the "down slope" right past the top of the 12 mark. hmmmmm gotta check out that EGR.

i think bbob made a post about how to check it , you need a buddy for it if i remeber right becuse someone needs to crowd the throttle in drive to ensure the diaphram moves

cool thanks. i don't know how or why i missed that convo, but i found it. gonna go tackle it now.

okay, when i push up under the hat of the egr, it stumbles and when i lightly power brake it, i don't feel much at all. It had to be fed a little more than "light" throttle to feel anything. I set the timing back to 10* and it's still knocking. Could the TPS be out of adjustment and causing this? I've put 3 different brands of 93 ocatane in it, so i've ruled that out. i may just replace the egr stuff to be sure anyhow?

how much did you guys advance your timing?

I'm running mine at 13 and use 87 octane gas. Sounds like you can get away with using cheaper gas on pre 1989 engines since they were lower compression engines.

i may just replace the egr stuff to be sure anyhow?

A lot of the time our EGR valves are OK but the control solenoid is shot. Just connect a vacuum guage between the solenoid & EGR valve.

When you start a cold engine there should be no vacuum present until over 140° F. The vacuum should rise from 0 to 10 or 11 in. Hg & vary as you drive around. Should be no vacuum with throttle closed or under hard acceleration.

If the vacuum readings tend to stick at a certain level (high or low) the solenoid isn't working properly -- check wiring first & of course the vacuum tubing. If it always tends to be near the lower end of the range your EGR valve may be leaking.

Only use the right AC Delco EGR valve for your car if you need replacement. Stay far away from aftermarket EGR valves.

Make sure your EGR system is functioning properly if running with advanced timing or things can get very expensive.

How much do you think a mechanic would charge to do something like that? I've never put anything less than 93 octane in any car I've ever owned so that would not be a problem. Don't bother trying to explain it to me as I'm am not very mechanically incline. I trouble shoot a 16 cylinder 9072 cubic diesel engine for training which has of course very large systems which are easy to follow(Just to give you an idea of how big the engine is, the turbocharger by itself weighs almost 4 tons). But for some reason, I cannot apply what I know about those engines and make my engine make seem less complicated to me(although it has helped alot).

How much do you think a mechanic would charge to do something like that? I've never put anything less than 93 octane in any car I've ever owned so that would not be a problem. Don't bother trying to explain it to me as I'm am not very mechanically incline. I trouble shoot a 16 cylinder 9072 cubic diesel engine for training which has of course very large systems which are easy to follow(Just to give you an idea of how big the engine is, the turbocharger by itself weighs almost 4 tons). But for some reason, I cannot apply what I know about those engines and make my engine make seem less complicated to me(although it has helped alot).

Of course your engine would not seem that much less complicated - diesel systems are very different from those of gasoline. I'm curious - what kind of application would use a motor of that size?

That being said, I would think that it would not even be worth an hour's worth of labour from your mechanic. Timing advance is a very simple procedure - just take it to a mechanic who knows the motor and preferably a mechanic who does not charge labour by the hour - my mechanic charges in 10 minute increments.

We use that engine to spin a generator that provides 1.5 megawatts of electricity. Believe it or not, it's one our portable systems. I know the fundamental difference between diesel and gasoline engines is that diesel compresses the fuel/air mixture to a flash point that explodes and forces the piston down while gasoline does the same thing by igniting the fuel/air mixture with a spark. But other than that they both have timing belts/chains that spin the camshaft which ensures the proper timing of the intake and exhaust valves. It still just seems a bit more complicated on a car and I'm afraid I'll make a mistake I can't afford.

ignition timing isnt much diffrent than injection pump timing on smaller diesels , then again you may not have a injection pump on that 9000+ cube engine , you might be working with the detroit style injection running a pushrod to pressureize and open the injector (im curious which one?)...

man i bet its rewarding to work on those , biggest i delt with were 8v92tta detroits (92 cubes per cylander for those non detroit speak folks)

Keep in mind that the 4.1/4.5/4.9 engines have a distributor that feeds info to the ECM. The pickups inside the distributor send the engine crankshaft position info to the ECM and the ECM then determines the correct spark advance and delivers the correct advance via the HEI or EST line to the module in the distributor. In otherwords, the ECM actually "fires" the spark via a signal over the EST line. All the distributor does is to send the reference signals from the pickup coil to the ECM and the ECM does the rest. The ECM just fires the spark , however, the distributor rotor routes the spark to the correct post on the distributor cap (depending on which one it is pointing to). That is why the spark plug wires from the various cylinders must be installed in the correct order. THAT determines which cylinder gets the spark. The correct approach is to properly synchronize the distributor orientation in the block with what is built into the ECM logic so that the system will operate "correctly". This is what you do when you time the distributor to 10 degrees with a timing light. You are just synchronizing the timing signals from the reluctor wheel inside the distributor with what the ECM logic has been programmed to expect. Fortunately, on the 4.x engines, you can jimmy this by deliberately mis-setting the distributor reference setting (or "timing") by biasing the distributor position a few degrees. This then sends the reference signals to the ECM a few degrees advanced (for power if that is what you want) or retarded (for regular fuel if that is what you want to run) depending on how you set it. Then the ECM is still expecting the "correct" reference setting but it is deliberately "off" by how much you changed the setting. All the crank position reference info for the ECM to operate with comes from the distributor on the 4.x engines so it can be adjusted slightly to compensate for conditions. On the NOrthstar this is impossible because all the reference info on the crank position comes from the crank position sensors that are located in fixed pockets on the block and read the crank position directly. No adjustments required or possible.

How much power can this actually add? Any dyno results out there? I don't really care, but it would at least be interesting.

a kick in the butts worth... no idea, best guess would be 7-8hp and 7-8 lbtq??

yeah, a manual advace works pretty well, alot better than those damned superchips.

the chips take away the speed limiter (130mph or so I heard on the '93 DeVille) :burn:

the chips take away the speed limiter (130mph or so I heard on the '93 DeVille) :burn:


yeah but i just got mine and took it right out promptly. the car sounded like a wounded lawnmower and would not go into drive!!! it might have something to do with the mods i have already done, or a bad chip, or even the wrong chip. but i dont see how it is possible to have the wrong one, as i made sure the serial numbers on my newer ecm was a match from the old one.
superchip problems:
poor startup.
very high idle once car starts (1500 rpms).
put car into drive, inches forwards, but goes nowhere when pedal is pressed to floor, during which the car sounded like a lawnmower.
knocking, even though i retarded the timing.
anti-theft (pass) kicks in, can still start the car though.

i am thinking a 4th possiblity, the antitheft (PASS) is causing this. i will have to get into that a little later though. does anyone have any suggestions here?