Setting Timing


Active Member
Feb 15, 2013
Hi all,
1986 GN, 19K miles, stock injectors, running 93 octane pump gas, 13-14 lbs boost, adj fuel regulator.
Turbo Tweak chip for stock injectors and 93 octane gas.
Looking for suggestions on what I should set the timing at?
Also, any advice on draining gas tank is much appreciated. I know I can jump the fuel pump, but not sure how to capture gas safely with that method. I've got some old gas I'd like to get out of the car in prep for first drive in 2 seasons. Tried siphoning with no luck.
Thanks all,
30 year old car with 19,000 miles and only been sitting two years......

At any rate there's a LOT more that needs to be done than just old gas.

You need a top timing gear, drop the pan, replace the injecotors (yeah yeah, I know.... 'clean them'... which is right at there with buying new 60's.) modern chip, Translator (a 19K MAF will fetch big bucks from the uneducated), valve springs, spring cleaning, boost hoses, blah blah blah....
Hi Earl (always thought your handle should be "grumpyearl". You are one of the most prolific posters on the site and one of the most brutally honest posters, for sure, with the best advice and clear you care a bunch about keeping these cars healthy. I'm second owner, purchased three years ago, after it had sat for 18 years. Had 17K + miles when I purchased. Pulled tank, drained tank, all fluids, hoses, belts and filters swapped. installed scanmaster, vacuum brakes, new headliner, plugs, racetronics fuel pump, hotwire, etc. Got her running knock free on 93 and about 13.5lbs. Installed TT and just want to be sure I have her timed right.
Just flunked inspection yesterday as muffler finally rusted through, so new y-pipe back exhaust going in today without cat.
I used the 3/8 ID clear hose hooked up to fuel rail and pump bypass to empty tank (just about) as the gas was over a year old since I last ran her.

Much appreciated Earl, you were helpful two years back in getting me sorted along with others.
I'm trying to stay as stock as possible, but as you've called out a bunch of times, I don't want to hurt the car in the process.

Valve springs is another bit I've been thinking a lot about. Seems like that is inevitable along with timing gear.
Hi Joel, you can get one of those little hand pumps (usually red) with clear hose at Harbor Freight or any parts store and pump out the old gas into a gas container. I've done it when I put in my fuel pumps a few years ago. Depending on how much gas you got in there it may take awhile. Jumping the fuel pump requires you to remove the schrader valve in the fuel rail and attaching a hose to the port securely. It will pump out the fuel. Last we talked you were still seeing some knock, is that why you want to dial down the timing? You can turn it down a few degrees to see if it makes a difference after the fresh gas is in.
Thanks, good to hear from you pronto, yes was the knock, jumped the fuel pump and used clear line into tank, worked great.
Was running excellent when I went for inspection, muffler rotted through, installed dual from y-pipe back, minus cat. Now shifting very differently, feels late and soft, same with downshift.
Thoughts. was shifting perfectly this am prior to exhaust replacement.
Replacing the exhaust should not have effected the trans shifting unless the TV cable was disturbed...
Coincidence that after the new exhaust is hooked up that it is shifting softer, make sure the TV cable is set correctly at the butterfly valve.
Ya, look up setting the TV cable to see if that helps. A free flowing exhaust will change the feel of the power band but not transmission.
You were correct pronto and Chuck, tv, I adjusted and back to normal. No idea what changed as they were not very close to it when working on the exhaust.
Thanks my friend,
Good to hear! So, any difference with the new exhaust? Must sound better. Who's system is it?
Sounds good, I tried to keep it relatively laid back, Lou's did it, in stainless, Derry. Nice guys and they did really nice work, 5 hours or so. Bunch of knock though. I checked fuel pressure and all seemed OK, 43 line off and 36 line on, built some boost in driveway and fuel pressure built at about 1lb per 1lb, tough to tell for sure. I have the knock I've ever had and I'm running around 13-14lbs of boost, I'm going to back that off. Fuel is fresh and 93. stumped. I"m almost tempted to drop the stock chip back in, as I had no knock with slightly lower boost.
Valve springs are defiantly on the list of must haves. The were weak back in 1987 and they haven't gotten any better in the last years. A new set of springs will really wake the engine up (and stop the valves from getting burnt on the sealing area).
Almost always when I have knock it's the fuel pump starting to fail. I tape a gage to the windshield to verify pressure isn't keeping up to the ((1) pound of boost to the (1) pound of fuel pressure) test.
Freer flowing exhaust is going to need a bump in fueling. The chip was burned for a full stock exhaust. You could add a few points to the base fuel in the chip.
Yes, I need to install my fuel pressure guage, that maybe something you can help me with Pronto, when I come over some night you have a bit of time. I tried the tape to my windshield method and almost killed myself. Unfortunately it is a bit of a ride for me to get to someplace open enough to check guage while driving. I can't brake boost much pressure before the rear tires light up. I am anxious to get a handle on this. Pronto, should I go for more than 43lbs at line off? How do you mean add a few points to the base fuel in the chip? PS I'm looking forward to seeing your car at the track.
Thanks guys,

I can see a powerlogger likely in my future, but in the end, I'm just trying to get a good, completely knock free tune at 13-14lbs of boost with most all things stock.

PS - For what it's worth, Fuel pump is racetronics and 2 or so years old.
Sum'n going on here if your running a TT 93 chip, If memory serves his stock injector chip is 18/17* in default, which is less than the factory chip. At only 13-14 psi your getting KR? How much? You have a SM correct?
Yes SM.
Yes TT chip for stock injectors and 93.
I've seen double digit knock once
And single digits
Have not been able to go WOT for fear of knock and have not been in it too much because of the knock
I thought possibly old gas but that can now be ruled out.
I need to double check my vdo boost gauge as I'm not certain it is correct as I'm seeing more boost in dash than VDO. Need to sort out a precise boost measurement clearly.
Based on test with fuel gauge and fuel pressure build with what I believe to be good fp regulator I think dash is much more accurate than the VDO gauge.