Stock Ignition Timing Map

[StarquestRescue]

To be honest i had never checked the knock sensor on my modified 88. And it has been a long time since i checked the vacuum advance/retard actuator.

 

So i enabled the sensor at idle by disconnecting the wire to ecu pin 61. Taped on the mixer body like is shown in some of the early manuals. Nothing happened, taped on the intake still nothing. Got out a 1/2 in extension and raped on the boss with the casting date code on it. (Right under the pass side front of the head). Now i could get it to retard from tapping on the iron block with the steel extension.

 

It responded much like i said earlier about my 87. After some experimenting, i was able to strike the block hard enough to get the full 12* retard from one strike. After which the timing hangs at full retard for a little bit, and than starts to slowly advance back to normal. In all it toke about 15- 20 seconds for the timing to return to normal from full 12* retard.

 

Next i applied air pressure to the actuator and got about 12* retard. Applied vacuum and got about 14-15* advance. I believe this is the advance / retard unit i purchased from mitsu for an 88 auto car. Hum, once again the old manuals seem to be inaccurate.

 

There is no substitute for real world testing.

 

Next test to do is to wire a light to the boost retard solenoid on the air can and see if i can get it to activate by raping on the block

[Lizzord30]

To be honest i had never checked the knock sensor on my modified 88. And it has been a long time since i checked the vacuum advance/retard actuator.

 

So i enabled the sensor at idle by disconnecting the wire to ecu pin 61. Taped on the mixer body like is shown in some of the early manuals. Nothing happened, taped on the intake still nothing. Got out a 1/2 in extension and raped on the boss with the casting date code on it. (Right under the pass side front of the head). Now i could get it to retard from tapping on the iron block with the steel extension.

 

It responded much like i said earlier about my 87. After some experimenting, i was able to strike the block hard enough to get the full 12* retard from one strike. After which the timing hangs at full retard for a little bit, and than starts to slowly advance back to normal. In all it toke about 15- 20 seconds for the timing to return to normal from full 12* retard.

 

Next i applied air pressure to the actuator and got about 12* retard. Applied vacuum and got about 14-15* advance. I believe this is the advance / retard unit i purchased from mitsu for an 88 auto car. Hum, once again the old manuals seem to be inaccurate.

 

There is no substitute for real world testing.

 

Next test to do is to wire a light to the boost retard solenoid on the air can and see if i can get it to activate by raping on the block

 

Great info! Ill try to test the same stuff once I get mine going. Test the knock sensor, and boost retard, unforntaly I dont have a vacume pump(i should get one lol)

 

I have no idea if the knock sensor works on this thing so i better test it before I really try to do much.

 

I like how it retards quicklly retard then slowly gain over 15 to 20 sec. But really makes it so you dont want it to kick in in the first place.

 

boost retard of 12 is not bad at all. Maybe with adjusting the hex on the advance it can get a bit more im curious.

 

I think maybe I will wire in the activation of the boost retard into the check engine light! that would be cool lol. Then if I get bad gas or some other boost issue I will get a warring right away!

 

I dont remember does it trigger the lower boost setting also when it detects knock on the 88-89?

[Shelby]

Luke I ran a completely stock dist mechanical adv with my 20g up to 20 lbs and never had any spark knock problems , I realy don't think your gona need to do any thing other then make sure every thing is working to specs

 

all I did was use a oem caravan ign igniter with no knock box , stock coil

 

you will want to disable the kick down swt ( passing gear swt )

 

and if you have a carb'd vac adv unit you can easily see the arms connect very defferantly so you can not use the wrong one

[Lizzord30]

Luke I ran a completely stock dist mechanical adv with my 20g up to 20 lbs and never had any spark knock problems , I realy don't think your gona need to do any thing other then make sure every thing is working to specs

 

all I did was use a oem caravan ign igniter with no knock box , stock coil

 

you will want to disable the kick down swt ( passing gear swt )

 

and if you have a carb'd vac adv unit you can easily see the arms connect very defferantly so you can not use the wrong one

 

This is not just for me more just to get the info out.

 

But for me i am running without an ic and maybe 87oct becuse i am cheap lol.

The 90 trans has a kickdown cable so somehow i need connect it up havnt tryied yet.

[Shelby]

why no IC you should have a couple laying around

 

besides you know dam well you can't be boosting no 15 lbs with out an IC

[Lizzord30]

why no IC you should have a couple laying around

 

besides you know dam well you can't be boosting no 15 lbs with out an IC

 

Yes i do have a couple!

 

A few reasons I dont want to run an IC

1. Would have to remove my hood latch and use hood pins (dont want too)

2. Would incress lag I like the instant response that non IC give you, basically raising the RPM band and I rather more tq down low and with a more gradual power band at the low end. (better off-road power)

3. I only plan to run 10psi anyways.

4. I have a large Radiator and with the engine swap the engine is 1.75in more forward in the engine bay so with combo of large radiator and engine more forward gives no room for fans or fan clutch on the engine bay side of the Radiator So I need to run fan/s On the bumper side of the Radiator that would be in the way of the IC.

5. Just not needed that much power. Even a stock non IC engine Will make a good deal more then power then the stock v6. Of course mine wont be stock lol.

Edited May 6, 2013 by Lizzord30

[Shelby]

are you kidding it actualy takes time for all that air to travel down 15 ft of pipeing and across an intercooler

 

I know exactly what you mean the day I added an intercooler to my truck for $2cents i'd have removed it the same day

[Lizzord30]

I think part of the problem is the ecu counts all the air so you end up running ritch, where with the non ic is alot more intime with what the engine gets.

[Threedoor]

Were the non-intercooled cars designed to have more mechanical advance (from weights and springs) than the intercooled cars since they were designed to run lower boost pressure, or less advance due to being designed to accept a hotter air temperature entering the throttle body? Or did they stick with the same dizzy for all years?

 

Thanks,

 

Keith

[Threedoor]

There are two different curves, one for intercooled cars and one without, that is the difference in springs.

Were the non-intercooled cars designed to have more mechanical advance (from weights and springs) than the intercooled cars since they were designed to run lower boost pressure, or less advance due to being designed to accept a hotter air temperature entering the throttle body? Or did they stick with the same dizzy for all years?

 

Thanks,

 

Keith

 

Well, wish I had read the whole thread before asking I will finish reading before posting any follow up questions.

 

Keith

[Threedoor]

Yes i do have a couple!

 

A few reasons I dont want to run an IC

1. Would have to remove my hood latch and use hood pins (dont want too)

2. Would incress lag I like the instant response that non IC give you, basically raising the RPM band and I rather more tq down low and with a more gradual power band at the low end. (better off-road power)

3. I only plan to run 10psi anyways.

4. I have a large Radiator and with the engine swap the engine is 1.75in more forward in the engine bay so with combo of large radiator and engine more forward gives no room for fans or fan clutch on the engine bay side of the Radiator So I need to run fan/s On the bumper side of the Radiator that would be in the way of the IC.

5. Just not needed that much power. Even a stock non IC engine Will make a good deal more then power then the stock v6. Of course mine wont be stock lol.

 

If you ever do want more power without the intercooler, and E-85 is available in your area it is a great fuel... sort of a pain in the butt on a starquest since our fuel lines don't tolerate ethanol worth a damn. Even running modern pump gas (E-10) will jack up our fuel system over time, E-85 will accelerate the process.

 

Back to my original question... do the non-intercooled cars have more or less mechanical advance?

 

Keith

Edited May 7, 2013 by Threedoor

[scott87star]

Less.

[MikeMeyerhoff]

The differences for ic vs non-ic in the the 87 drivablity troubleshooting manual, are listed for the mechanical governor as 33* at 6000 rpm for ic and only 25* at 5000 rpm for non-ic. Thats not really much difference.

 

The vac advance is the same for non-ic and ic at 15* for 260mmHg.

[Shelby]

sorry but the difference in 8 degrees timeing is enough to burn a piston or break a ring land

8 degrees is a lot , don't think so adjust your base timeing to 2btdc and see how well your car runs

[Threedoor]

sorry but the difference in 8 degrees timeing is enough to burn a piston or break a ring land

8 degrees is a lot , don't think so adjust your base timeing to 2btdc and see how well your car runs

 

Problem is you cant really compare them because they are at two different RPM points 1000 RPM apart.

 

Keith

[Lizzord30]

Yea its not like most tbi car will be making all that much power above 5k so doesnt really matter lol unless your overreving shouldnt need the 6k timing.

[Threedoor]

Yea its not like most tbi car will be making all that much power above 5k so doesnt really matter lol unless your overreving shouldnt need the 6k timing.

 

Right! We know that the non-IC cars have 25 deg at 5000 RPM. The question is how many deg of timing does the intercooled setup have at 5000 RPM from the factory?

 

Keith