5.0blackcamaro

i was just wondering, does my '88 305 tbi camaro have a rev limiter on it, or would it just keep reving till it blows up, it redlines at 5,000 rpm, but sometimes when im showing off or driving hard i dont look at my tach and im wondering it it gets overreved. thanks for any replies

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regal301

if it has the correct ignition module (not a truck module) it will rev till the valves float or a rod snaps !!!!!!!!
unless you want to blow it you should pay attentiont to the tach !!!!!
5000-5500 is the max on stock high mileage parts.

5.0blackcamaro

my car has the stock engine and throttle body all original, and one time i put the transmission (its an automatic) in 1st/low and romped it to show off for some people, and held the pedal down for a while. I thought back to when i did it and wondered if it stoped at 5,000 rpm or not, because i hoped i didnt overrev it. The redline on the tach is at 5,000rpm, but would it hurt it to go to 5,500rpm? because I know a 350 can go that high.

DJ_91RS

I would like to think you would have heard the valves floating and let off of it....how long is a while?

Dave

5.0blackcamaro

im runnin straight pipes, so i got no mufflers. when i let of of it i heard loud popopopopopo sound as it decelerated. I thought the automatic would shift if the revs got to high even if it was in 1st low or 2nd low.

DJ_91RS

Straight pipes have a tendency to making that popping sound. How does it sound at idle? I would think that as long as there is no ticking/tapping sound and you are not blowing any smoke out of the exhaust I would say you are ok, though if you did float a valve or valves for an extended amount of time, you may have weakened the valve springs. Just be sure to watch the tach and shift before redline.

Dave

5.0blackcamaro

my car only has 63k original miles on it, and when i bought it it already had a valve seal problem that makes it puff a small amount of blue smoke when you start it up, and it also had a ticking lifter. Ever seen this on 305's?

tony_cogliandro

do you know when the rev limit was incorporated into the camaro?

5.0blackcamaro

the car is 100% stock except for the exhaust

regal301

im not 100% but i think the tbi truck ignition modules had a 5k rev limiter built in.they interchange with the cars but have a limiter (someone correct me if im wrong)

DJ_91RS

My 305 has a bad valve seal also and the little puff of smoke on start up. That will be addressed this year when I freshen up the motor. As far as the limiter goes, I am trying to find out when it was introduced. On my car it is not so much a rev limiter as it is a speed limiter. When I get to 112-115 it kicks in until I slow down under that. The ticking lifter could be just it is gummed up a bit. You could use something to add to the oil to see if it helps get it unstuck.

Dave

5.0blackcamaro

so my car could possibly have a truck module in it?

RBob

The TBI Camaros and Firebirds never had a rev-limiter. In the ignition module or ECM. I think it is the weak valve springs and/or the intake ports that give up first. With the '8746 ECM in the '89 - '92 MY's there is a speed limiter. Which many people hit.

I've used truck ignition modules to over 7K. So I don't believe that there is a limiter there either. It would be interesting to see which module that GM used in the TBI cars. Just lift the distributor cap and check the 3 number code on the top of the module (such as 048, 369, ...).

Then post back with the numbers.

RBob.

__________________

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'92 Camaro in Dark Green Gray Metallic

regal301

i pulled the cap on my car (tuned port) its a 369
and i have a dist from a camaro rs (305 tbi) its a 048
havent checked my 91 caprice ( lo3 )

i thought there was somthing funny with the tbi module........ and i found this in another forum and found this

"I am tired of hearing people say this. ITS NOT THE HEADS PEOPLE. The TBI engine actually peaks at a slightly higher RPM than the 70s smog heads used before them. Guess what they have the same cam and same exhaust setup. The weakness in the TBI engine is the cam, exhaust, and factory prom tuning. Even the factory intake and TBI are not much of a restriction until you have passed 280 flywheel HP."

" For those of you noticing a fall off of power after 3,500 rpm on even a stock TBI engine in good shape, pop off the distributer cap and look at the ignition control module. If its a stock GM module, look at the numbers inscribed in it. You will either have 048 or 369. The 048 is a TERRIBLE module to have as it will pull a ton of timing over 3,500 rpm. The 369 will actually add a 2* of timing advance over 4,000. The 048 was like a built in rev-limiter, the 369 was used in performance applications and applications that needed upper rpm performance. TPI Camaros/Firebirds and TBI Fullsize Vans and 9C1 cop cars came with the 369 module. TBI Trucks and Civilian B-cars as well as TBI F-cars came with the 048 modules."

http://www.chevytalk.org/fusionbb/sh...hp?tid/205486/


there are timing charts pulled from both modules. i thought the advance was handled by the ecm.

now when i go to autozone's website they list only one module for all the apps that use the 8 pin module............. when the gm ones are different.

RBob

Thank you for posting your module numbers and engine type. The 048 and 369 are also the modules I've found on many TBI trucks.

Here is the original TGO thread for module latency:

http://www.thirdgen.org/techboard/di...ncy-table.html (ebl SA latency table q's)

You are correct that the ECM controls the spark timing. There is also a latency table in the ECM's calibration to compensate for the ignition module delays. What is interesting about what was found is that the calibration doesn't always fully compensate.

This is where the retard comes in with the 048 module. The latency table doesn't fully compensate for the module.

And with the 369 module it over compensates. Hence the 2 degrees of advance.

Note that in the original thread, the testing of each module was done with different latency table values. Each module was checked with each table.

At the lower RPM's the 048 module matched table 1.

While at the lower RPM's the 369 module matched table 2.

And that the 369 module's table (table 2) has greater compensation then the 048's (table 1) values.

In the end, it would be best to re-work the latency table to match the module. In that thread Cflick did just that. Then there won't be any difference between modules as long as the correct latency table values are used.

RBob.