I am running a Tuned Port ECM (1990-1992 camaro 305) on my 4.9 (with Allante intake and 5 speed trans)

It runs great except I keep getting code 43 because I cannot find a place to mount the required knock sensor (4.9's don't come with one)

All the threaded holes in the block and heads are for bolts only and there is no brass adapter available to adapt the tread of the knock sensor to a metric bolt thread.


...... anyone have a solution?

I'll be surprised to get an answer on this one.....

bump anyway

I think Ryan answered this question in the 7730 ECM thread. You basically find a boss without any bolt holes and drill and tap your own hole. Many cars have the type of sensor that simply bolts to the block, not into the water jacket like I wrote. What type sensor does the 4.9 use? Can the 7730 be used with it?

quote Originally posted by Hudini: I think Ryan answered this question in the 7730 ECM thread. You basically find a boss without any bolt holes and drill and tap your own hole. Many cars have the type of sensor that simply bolts to the block, not into the water jacket like I wrote. What type sensor does the 4.9 use? Can the 7730 be used with it?

Yea, I read that thread (very good thread) But the 4.9 doesn't come with a knock sensor. It only has two very tiny drain plugs

But thanks for your reply

Just plug it in to the harness, and tuck it someplace out of the way.
As long as the engine doesn't knock with it plugged in, it should be okay.

As long as the code is set, it's probably using very conservative timing tables. Once the code is cleared the engine ought to run better, but it might advance the timing to the point where it does knock, expecting the knock sensor to detect when it is.
You might have to back off your initial timing just a bit.

This is all speculation on my part, however.

If you can get the software for the TPI, I'm pretty sure that the knock sensor can be "programmed out".
Tunercat has the definition files for the TPI. It's probably one of the most popular engines in the world.
$8D definition file. (You *are* going to tune it... right?)

I stuck mine on a boss on the top of the transaxle near the back of the engine. Not ideal, I know. Of course, this is with a TBI computer and the knock sensor is nearly useless, even when it is in the correct location.

Thank you cooter and raydar....

I still have to finish my exhaust (no mufflers yet).... When done I will be able to hear if there is any knock, if any. If so, I will have to adjust the timing a little retarted untill I can find a suitable spot to mount the sensor....... or have the prom reprogrammed.

Caddy v8, 4t60 (non-e), Holley TBI, and a truck ecm (747). The TBI is not as bad as people think- at the time I was putting this together, there was no editor for the Caddy ecm so this was an easy to wire alternative. I just spliced a little here and there into the original Fiero harness, swapped a couple of pins around in the ecm connectors, and used a PROM for a 305 truck. It ran decent with a stock program and I have tweaked it some to improved driveability.

I think you should just bypass it, and run 91 octane.

I found a knock sensor that will bolt on the 4.9!!!!

It has the same resistance as the required Z-28 knock sensor(for the 1227730 ecm)...... but the thread is the same as most of the metric bolt holes found around the 4.9

Not sure what the application is for but the part number is SU1128 available at Autozone for around $35

Forgive my nievete (and probably spelling) but if you are getting that computer to work, then does that mean it would also support a 4T60E transmission? I am doing the 4.9 swap also and am looking at the 4T60 because some reason I can't remember now, it's been so long! Something about programability (or the lack of it) as the engine I have is PBJ's old turbo 4.9 I hope this makes sense to someone because I confused myself.

This ecm can NOT operate a 4T60E transmission or any other electric (computer controlled) transmission. It will operate the lockup functions on older transmissions like the 4T60 (440T4) and TH125C

The main reason I went with the 1227730 ecm is that it can be run with a manual transmission without the need to reprogram the prom and because premade wiring harnesses are available and cheap...... No one makes a cheap "stand alone" wiring harness for a Cadi ecm.

quote Originally posted by countach711: Forgive my nievete (and probably spelling) but if you are getting that computer to work, then does that mean it would also support a 4T60E transmission? I am doing the 4.9 swap also and am looking at the 4T60 because some reason I can't remember now, it's been so long! Something about programability (or the lack of it) as the engine I have is PBJ's old turbo 4.9 I hope this makes sense to someone because I confused myself.

If you are using the Caddy ECM, I don't see why the 4T60E will not work.

v8fiero400 - now for my stupid question, where do you need to mount the knock sensor (block or the head)?

With this new knock sensor, I could easily mount it on either the heads or block...... I chose to mount it on the block.... I think it can detect all preignition better that way.

quote Originally posted by Mickey_Moose: If you are using the Caddy ECM, I don't see why the 4T60E will not work. v8fiero400 - now for my stupid question, where do you need to mount the knock sensor (block or the head)?

You jogged my memory, that and a decent night's sleep. I think it is a camaro computer now and that's why I can't run the E tranny. Using the Camaro computer had something to do with the turbo.

The 1227730 ECM and Prom combo that will work on a 4.9 is found on 1990-1992 tuned port injected (305 only) Camaro's and Firebird's

a 350 prom would run way to rich on a 4.9

That ECM was also found on quite a few cars. My 7730 came from an '88 Beretta with a 2.8L. It also came on cars with the 3.1 turbo and that is the code mask Darth Fiero uses to base a turbo engine.

Application: 1987 2.0 L4 TBI “1” LL8
1988 2.0 L4 TBI “1” LL8 (early)
1987-89 2.8 V6 PFI “W” LB6 (exc. “W” body)
1988-94 3.1 V6 PFI “T” LH0 (exc. “W” body)
1990-92 5.0 V8 TPI “F” LB9
1990-92 5.7 V8 TPI “8” L98 (“F” body)

For the 7730 with TPI harness, does that harness work with the 4.9 distributor factory plug or does it needs modifications? Wiring or otherwise?

Thanks!!

quote Originally posted by v8fiero400: This ecm can NOT operate a 4T60E transmission or any other electric (computer controlled) transmission. It will operate the lockup functions on older transmissions like the 4T60 (440T4) and TH125C The main reason I went with the 1227730 ecm is that it can be run with a manual transmission without the need to reprogram the prom and because premade wiring harnesses are available and cheap...... No one makes a cheap "stand alone" wiring harness for a Cadi ecm.

[This message has been edited by aaronrus (edited 09-27-2007).]

I understand the 7730 will not control the transmission. I am using an aftermarket controller for that because I intend to install paddle shifters on the steering wheel since this is to be an autocross car and I need control of the shifts (you don't want to upshift or downshift in a turn - very bad things happen when the torque is removed from the drive wheels in a turn).

My questions are very specific.
1. Will I need to change the harness for the TPI for the 4.9 distributor or will it plug in?
2. Will the injector harness from the 4.9 work or will I need one a TPI one?

I understand the 7730 will not control the transmission. I am using an aftermarket controller for that because I intend to install paddle shifters on the steering wheel since this is to be an autocross car and I need control of the shifts (you don't want to upshift or downshift in a turn - very bad things happen when the torque is removed from the drive wheels in a turn).

My questions are very specific.
1. Will I need to change the harness for the TPI for the 4.9 distributor or will it plug in?
2. Will the injector harness from the 4.9 work or will I need one a TPI one?

They're both HEI's. There shouldn't be a problem. The Caddy distributor just has a cam position sensor built into it. That's the major difference. If you don't need the cam synch signal, don't hook it up.

Sounds like I need to put the TPI plug on the 4.9 Distributor and leave off the connection for the cam sensor. Can I swap in the complete TPI distributor? (not that I would go that route)

Thanks!

I would guess no, you can't swap dizzies, but I don't know for sure. There are some strange dizzy swaps that work... Take the HEI from a Chevy stovebolt 6, put and AMC V8 dizzy gear on it and it will plug into an AMC 258 (or Jeep 4.0)...

I would keep the connector for the cam sensor plugged in and run the wiring to your ECM and just leave it. That way if you ever end up going back to the Caddy computer (if it gets hacked, for instance), switching back is relatively easy.

I'm also planning to to run the painless wiring harness which is why I'm asking. Anyone else running the painless harness and made this mod?

To use the TPI knock sensor you can drill and tap a 1/4 npt hole in the 4.9 block on the transmission end, the side closest to the rear window of the Fiero. There's a nice flat spot there. You could also use a '93 Northstar sensor, which has straight M10 theads. Knock sensors are supposed to be matched with the filter (in the memcal on a TPI), and they are also tuned to the specific engine they are designed for, so it's questionable how well any of them will work in a 4.9. I used a TPI sensor in one of mine and it seemed to work fairly well. I don't remember if it was for a 5.0 or 5.7. If you don't care about making it function or don't want it to sense false knock you can just wire a resistor to ground in place of the sensor. With the code 43 presnet it will run on an RPM based spark table and a noticeable reduction in power. The 4.9 takes a lot more spark advance than a TPI, so tune away!

my guess is you want the donor car to have as close to the same bore size as your 4.9L. Here's why:
The knock sensor acts like an ear, "listening" for knock, and the ECM then retards the timing a set number of degrees until the knock stops. So why does getting the knock sensor right make a difference? Imagine church bells with different diameters... they make different sounds, so the "ping" or "knock" will "sound" differently in a 4" bore versus a 3" bore. Given that one could bore up to .060" in a cylinder, I'd imagine there is some leeway in either direction of standard bore size as far as the sensor is concerned.

The 305 (5.0L) Camaro/Firebird/Truck engine has a 3.736" bore from the factory. The 4.9L has a 3.62"bore. A .060" overbore on a 4.9L would make it near the 3.736 305 bore, so it is probably the best choice. Drilling and tapping the block, or purchasing an adapter of some sort is a must. I would only go this route, unless I was absolutely sure the northstar knock sensor is 100% compatible with the filter of the 730 ecm. Detonation will kill an engine very quickly, and this is something I would not to guess at when retrofitting.

quote Originally posted by v8fiero400: I am running a Tuned Port ECM (1990-1992 camaro 305) on my 4.9 (with Allante intake and 5 speed trans) It runs great except I keep getting code 43 because I cannot find a place to mount the required knock sensor (4.9's don't come with one) All the threaded holes in the block and heads are for bolts only and there is no brass adapter available to adapt the tread of the knock sensor to a metric bolt thread. ...... anyone have a solution?

what throttlebody did you use with your setup? the alante TB uses the caddy ISC motor, and i know the 7730 computers dont control them...

quote Originally posted by Will: They're both HEI's. There shouldn't be a problem. The Caddy distributor just has a cam position sensor built into it. That's the major difference. If you don't need the cam synch signal, don't hook it up.

....or get a distributor from a 1989 or earlier 4.5 or 4.1 (same as 4.9 distributor but without cam position sensor) ... the plug on these older distributors will plug right into the 7730 wiring harness.

[This message has been edited by v8fiero400 (edited 01-20-2008).]

quote Originally posted by v8fiero400: I used the stock allante throttle body without the idle control motor. I am using a "remote" idle air control valve "inline" with a vacuum hose.

how is your gas mileage with this setup? ive always preffered to keep the sfi of the caddy computer rather than switch over to batch fire of thr 7730, because of the economy issue, but i suppose if it is properly tuned, it wont make much of a difference...

quote Originally posted by rockcrawl: To use the TPI knock sensor you can drill and tap a 1/4 npt hole in the 4.9 block on the transmission end, the side closest to the rear window of the Fiero. There's a nice flat spot there. You could also use a '93 Northstar sensor, which has straight M10 theads. Knock sensors are supposed to be matched with the filter (in the memcal on a TPI), and they are also tuned to the specific engine they are designed for, so it's questionable how well any of them will work in a 4.9. I used a TPI sensor in one of mine and it seemed to work fairly well. I don't remember if it was for a 5.0 or 5.7. If you don't care about making it function or don't want it to sense false knock you can just wire a resistor to ground in place of the sensor. With the code 43 presnet it will run on an RPM based spark table and a noticeable reduction in power. The 4.9 takes a lot more spark advance than a TPI, so tune away!

I did quite a bit of research on knock sensors (more than I ever wanted to know) ... found this knock sensor with the frequency sensitivity compatible with a small bore aluminum engine block AND correct resistance for the 7730 ECM. PN 172390745 or SU1128 (at Autozone)....


This sensor has kept the 4.9 from pinging and knocking without over retardation... and screws right into the block, where a knock sensor should be.

... when I first had my 4.9 up and running the engine would knock at certain speeds when I was running the 305 knock sensor on the transmission. I had also tried other knock sensors (expensive trial and error before I did knock sensor research).... all would either keep the spark timing overly retarted, over advanced (knock and ping)... or pop up code 43

SU1128 is the only one to use with the 4.9 and 7730 ECM combo.

[This message has been edited by v8fiero400 (edited 01-20-2008).]

quote Originally posted by v8fiero400: I did quite a bit of research on knock sensors (more than I ever wanted to know) ... found this knock sensor with the frequency sensitivity compatible with a small bore aluminum engine block AND correct resistance for the 7730 ECM. PN 172390745 or SU1128 (at Autozone).... This sensor has kept the 4.9 from pinging and knocking without over retardation... and screws right into the block, where a knock sensor should be. ... when I first had my 4.9 up and running the engine would knock at certain speeds when I was running the 305 knock sensor on the transmission. I had also tried other knock sensors (expensive trial and error before I did knock sensor research).... all would either keep the spark timing overly retarted, over advanced (knock and ping)... or pop up code 43 SU1128 is the only one to use with the 4.9 and 7730 ECM combo.

V8fiero400, I'v got a 4.9 w/ Allante intake swap I'm doing in an 87 LeSaber t type Running the 7730 ecm, and I came up with a different way to have an iac, I modified the plenum to accept a throttle body from a 3800sc, I get the iac and more airflow in the process. I should have the car up and running soon.

Thanks for the info on the knock sensor, thats the missing link in my swap. A plus for ya.

Cheers Beers n Gearz. Joe

FWIW, according to AcDelco's online cross-reference, this sensor fits all Saturn models with 1.9L engine 1991-1995. LOADS of em in the U-Pull-It yards

As for using the Caddy ECM, Sequential Injection vs Batch fire on a V8 is negligible, and from what I understand around 2800 RPM it switches to batch fire, because the processing speed of the ECM can't keep up to keep the engine running. Then there's the factoring of the Speedometer Sensor, etc, where as the '730 works with the Magnetic VSS on the Fiero.

I'm mapping out an early TBI caddy harness pinout diagram to work on a 730 ECM on the 4.9 PFI motor. As a back-up, I am mapping out a Camaro/Firebird TBI harness and/or Truck TBI harness, since these seem to be much more plentiful at the yards I frequent.

[This message has been edited by Matt85GT (edited 01-21-2008).]

quote Originally posted by Matt85GT: As for using the Caddy ECM, Sequential Injection vs Batch fire on a V8 is negligible, and from what I understand around 2800 RPM it switches to batch fire, because the processing speed of the ECM can't keep up to keep the engine running. Then there's the factoring of the Speedometer Sensor, etc, where as the '730 works with the Magnetic VSS on the Fiero.

the caddy ecm is SFI at all times. not sure where you got your info from, but it is. The VSS problem is neglegble, because the vast majority of people have to get the VATS as well as other bits of code changed to get their 4.9L engines to run properly in their fiero, and you can program the proper readouts for the caddy ecm to generate the proper pulse for the speedo.

aside from rockcrawl( good luck getting ahold of him ), I am the only other person i know who reprograms caddy ecms, and i am the ONLY guy who adds the superchips/fastchips performance gains to it. 20HP and 15 lb/ft of TQ over the stock program, is well worth it

quote Originally posted by stickpony: the caddy ecm is SFI at all times. not sure where you got your info from, but it is.

http://www.thirdgen.org/tec...most.html?highlight= was where I was reading something, and I stand corrected. There is no difference at Wide Open Throttle.

quote Originally posted by stickpony: The VSS problem is neglegble, because the vast majority of people have to get the VATS as well as other bits of code changed to get their 4.9L engines to run properly in their fiero, and you can program the proper readouts for the caddy ecm to generate the proper pulse for the speedo.

With the 1227730 ECM, VATS is also eliminated, and proper VSS is also retained. I also like how much has been done with the $8D code of the '730 ECM, and it's ease of tunability, support for scanning, etc.

quote Originally posted by stickpony: aside from rockcrawl( good luck getting ahold of him ), I am the only other person i know who reprograms caddy ecms, and i am the ONLY guy who adds the superchips/fastchips performance gains to it. 20HP and 15 lb/ft of TQ over the stock program, is well worth it

This is where I'm very suspect of posted round number gains from a "Superchips/FastChips" program. I've never seen real-world dyno sheets for any of these so-called Fast Chips. I've looked at the TPI SBC version of their chip (admittedly not at the Cadillac specific tables) and all they did was add 10% timing and 10%fuel and eliminated VATS. I can do that myself with TunerCat, and tune specifically to my driving conditions, my car's behavior and my area's fuel quality, and come up with just as good of your posted gains, if not better. I'm not knocking your chip, I'm just stating I'm much happier with the flexibility of the 730 ECM on any engine as i am finding out.

quote Originally posted by Matt85GT: This is where I'm very suspect of posted round number gains from a "Superchips/FastChips" program. I've never seen real-world dyno sheets for any of these so-called Fast Chips. I've looked at the TPI SBC version of their chip (admittedly not at the Cadillac specific tables) and all they did was add 10% timing and 10%fuel and eliminated VATS. I can do that myself with TunerCat, and tune specifically to my driving conditions, my car's behavior and my area's fuel quality, and come up with just as good of your posted gains, if not better. I'm not knocking your chip, I'm just stating I'm much happier with the flexibility of the 730 ECM on any engine as i am finding out.

you raise a good point Matt, every setup has its advantages and disadvantages. for a person who isnt a tuner, the 7730 doesnt hold an advantage..for someone like yourself, it is good becuse there is alot of tunability with timing and fuel. for someone who wants a plug 'n' play solution, the caddy computer is better, since it works with al the stock hardware. two major advantages of the Caddy computer over 7730 on the caddy motor, the fuel economy is hands down better with SFI. the other is directed purely at those who have to have emissions testing done. the caddy computer pollutes alot less than the 7730, it just burns the gas more efficiently. we know that efficiency doesnt always equate to HP, but in the case of the caddy computer, it pollutes less, and generates good power. Capt Fiero posted his emissions results earlier, either in this thread or another one similar to it, WITHOUT a catalytic converter, and he still had very low pollution readings.

unless one is turboing the 4.9L, i dont see any need for the 7730 ECM, but then again, thats just an opinion, i'm not here to rustle anyone's feathers. I have my evidence to back up my statements, and that is what it is. i think the choice of ecm should be based on the end result of the product that the person who is doing the swap wants with their car...

I decided to calculate my fuel economy.

Well I added 8 gallons of fuel a couple days ago and my car ran 194 miles.... which calculates to about 24mpg. Not to bad.... mixed city and hwy driving. I think having the 5 speed manual helps alot.