Performance, Brainstorming & Tuning Talk about modifications, or anything else associated with performance enhancements. Have a new idea for performance/reliability? Post it here. No idea is stupid! (please use Detailing and Appearance for cosmetic ideas)

OBDII conversion - troubleshooting time

Thread Tools
 
Search this Thread
 
Old 01-06-2008, 12:18 PM
  #41  
Senior Member
True Car Nut
Thread Starter
 
sandrock's Avatar
 
Join Date: Aug 2004
Location: In your garage, swipin' da lug nutz
Posts: 3,067
Likes: 0
Received 1 Like on 1 Post
sandrock is on a distinguished road
Default

'Tis okay Bill. You must've been dipping into Katies special brew
Old 01-06-2008, 02:54 PM
  #42  
Senior Member
Certified GM nut
 
samueljackson's Avatar
 
Join Date: Oct 2006
Location: burb of detroit. 2 miles north of 8 mile Rd.
Posts: 2,028
Likes: 0
Received 1 Like on 1 Post
samueljackson is on a distinguished road
Default

i know that this may not be the most cost efficient solution, but if you have the original trans, then a swap to a 65e hd would solve a couple issues, and provide longevity for your project car.

just a thought , idk if u want to go that far tho
Old 01-06-2008, 05:14 PM
  #43  
Senior Member
True Car Nut
Thread Starter
 
sandrock's Avatar
 
Join Date: Aug 2004
Location: In your garage, swipin' da lug nutz
Posts: 3,067
Likes: 0
Received 1 Like on 1 Post
sandrock is on a distinguished road
Default

Not at this time.

Reason being is that I just rebuilt the trans from top to bottom this past summer. (see this for details).

Though I was joking around with Don about actually putting a Series One in front of a -65e. And on down the road, I might very well try that out. But I want to get some usage out of the trans that Sandy built
Old 01-10-2008, 09:44 AM
  #44  
Senior Member
True Car Nut
Thread Starter
 
sandrock's Avatar
 
Join Date: Aug 2004
Location: In your garage, swipin' da lug nutz
Posts: 3,067
Likes: 0
Received 1 Like on 1 Post
sandrock is on a distinguished road
Default

More updates.

Now that Gwen is all fixed up, jinx moved back into the stable. And there she will sit for many moons, because I stripped her of her engine harness (though I did take her for a spin around the block...damn I miss boost). During that time, I found SEVERAL issues with the original harness, and its a good bet that all of them contributed to her "personality".

First off was a bent pin at the firewall connector. B4 to be precise. What does B4 control you might ask? 5V reference to the ICM. Probably got kinked when the engine was put in at record speed during SEBF 2k6. And probably the cause of the phantom DTC19 that it would sometimes get, not to mention the hiccups under boost, the funky idle, and the huge hesitation when cold.

Next I find that the knock sensor wire is bare for about an inch at the sensor head. Again, another cause of my issues. That bare wire was probably picking up alot of stray current from the ignition wires, and going haywire anytime it got wet. I also found my T2V wires bare...this has no effect on engine operation, and the T2V worked fine, but I don't like it nonetheless.

Right now I am in the process of cutting out the leads I do not need anymore, and keeping the ones I do need (like the coolant temp signal, boost signal, T2V, oil pressure...you get it). The leads not needed are getting cut 7-12 inches away from the firewall connector, and will be reassigned new functions.

Pics to come later today.
Old 01-12-2008, 07:02 AM
  #45  
Senior Member
True Car Nut
Thread Starter
 
sandrock's Avatar
 
Join Date: Aug 2004
Location: In your garage, swipin' da lug nutz
Posts: 3,067
Likes: 0
Received 1 Like on 1 Post
sandrock is on a distinguished road
Default

*Sigh*

As I was going through the mangled mess of harnesses, I found even more differences.

1) TPS connections are different. Since they are electrically the same, I just cut off the OBD2 head and stuck on the old one.

2) Oil level sender operation is much different between the setups. S1s use an oil level module to keep an eye on things, and loops back to the instrument cluster. S2s actually have an input going to the PCM. In short, I am using the '93 configuration, and teeing off the level output wire to connect the new PCM.

3) No go on the cruise control, EVER. The new PCM uses an all electronic cruise servo, while the old one uses vac. assist. Since the new PCM does not include vent and vaccuum solenoid drivers, I can't use the original cruise control. Nor can I use the new style servo, since the cables that connect to the throttle body are different too. This effectively cuts this car out from being an over-the-road car. This fact alone can break many decisions on doing this mod.

4) Boost gage is also hooked in differently, so I went with the factory setup and taped back the OBD2 plugin.

Over the course of test-fitting the new harness, I decided to go back to the stock temp sender configuration as well. I've also done away with the following wires from the new harness (keep in mind I am trying to go off memory): Traction delivered and traction desired (these input and output at the EBTCM on 94-up models, 93'* have a much different setup), cruise lamp on, fuel pump PWM, and all associated cruise control wires. This basically leaves 2 data wires, battery feed, a/c control (3 total I think), fuel pump relay, high and low speed fan relays, iginition power and ground feeds.

And alot of long nights.
Old 01-12-2008, 03:39 PM
  #46  
Senior Member
True Car Nut
 
95naSTA's Avatar
 
Join Date: Feb 2003
Location: Philly
Posts: 4,508
Likes: 0
Received 2 Likes on 2 Posts
95naSTA is on a distinguished road
Default

For #3 I'm sure you can come up with something to make a S1 cable end work on the S2 curise servo cable. A local bike shop should have what you need.
Old 01-13-2008, 08:39 AM
  #47  
Senior Member
True Car Nut
Thread Starter
 
sandrock's Avatar
 
Join Date: Aug 2004
Location: In your garage, swipin' da lug nutz
Posts: 3,067
Likes: 0
Received 1 Like on 1 Post
sandrock is on a distinguished road
Default

Talked with a fellow member at length on what I am doing. He looked at a spare cruise module he had and the cable end seemd like it would work. But then I realised something. Pre-96 engines have their throttle and cruise cables running perpendicular to the dash (in other words, north-south), while the later models run east-west. So even if the new style cruise cable did fit the end of the throttle lever, the routing would be all wrong for it.

For the time being, cruise control is not in the picture. It'* not critical for engine operation, and could possibly have a solution worked out when it comes time for the"revision-b" update.
Old 01-17-2008, 10:29 PM
  #48  
Senior Member
True Car Nut
Thread Starter
 
sandrock's Avatar
 
Join Date: Aug 2004
Location: In your garage, swipin' da lug nutz
Posts: 3,067
Likes: 0
Received 1 Like on 1 Post
sandrock is on a distinguished road
Default

Updates.

I ended up going a different routing scheme than the normal routing. EVERYTHING would normally go through the firewall connector...power, grounds, data, you name it. Since I am using the '93 firewall connector for oil pressure, T2V, coolant temp, and oil level, I thought I would tap into the now vacant power conduits as well. All the switched and fused positives have been grafted to the '93 harness head. As it sits, about 3/4 of the original wiring that went through that head has been removed.

Now, there is the matter of data and signaling that must originate inside the cabin. I separated those wires right up to about a foot and half from the new PCM connections, and ran those separately. They will be going through the firewall on the driver side, and will more than likely share the same hole as the hood release cable.

Here they are.
Name:  DSCF0003.jpg
Views: 16
Size:  87.5 KB

These are the ground connections for both the new pcm and the old one. Note that the old PCM grounds also shared with some grounds in the cabin, which is why I kept them.
Name:  DSCF0002.jpg
Views: 16
Size:  50.2 KB

Here are other pics of how things are progressing. I plan on yanking off both the */c and the manifold for some touch-ups with the Dremel (mani got a nice treatment when the engine went in, and the */c is a Floz unit that really needs to be reworked) and some paint.
Name:  DSCF0001.jpg
Views: 17
Size:  143.0 KB

Name:  DSCF0005.jpg
Views: 16
Size:  135.1 KB

Name:  DSCF0004.jpg
Views: 14
Size:  136.3 KB

I *slightly* miscalculated the length needed for the EGR leads. I need to splice in another 6 inches or so to make it look right, and I may need to splice in a few more inches for the alternator hookup. Other than those two little snafus, the engine bay is almost all jacked in.
Old 01-17-2008, 10:36 PM
  #49  
Senior Member
Posts like a Camaro
 
Bonnevillan's Avatar
 
Join Date: Nov 2007
Location: MN
Posts: 1,172
Likes: 0
Received 0 Likes on 0 Posts
Bonnevillan is on a distinguished road
Default

this thread continues to amaze me...
all i know is, next car i buy will be post '96
Old 01-26-2008, 08:03 AM
  #50  
Senior Member
True Car Nut
Thread Starter
 
sandrock's Avatar
 
Join Date: Aug 2004
Location: In your garage, swipin' da lug nutz
Posts: 3,067
Likes: 0
Received 1 Like on 1 Post
sandrock is on a distinguished road
Default

Man I have been busy.

What started off as just another repaint ended up being a fully ported and polished Gen2, gasket-matched inlet, and polished throttle body Basically, I de-Flozed (or rather, did what he was SUPPOSED to do), and just by hand-turning it, feels 100% better. It got a coating of wrinkle paint as per the Great Wrendini, as did the throttle body. The intake manifold got a coat of high-temp aluminum paint, and of course all-new gaskets all the way around. I'll get pics of the new scheme and setup later this evening.

Now then, on to more electrical. Remember that post that mentions the ICM? I did some bench testing last night that confirmed my suspicions. Up until OBD2, the ICM grounded through the ICM plate and cylinder head mounting, then when '96 came along, the ICM got its own ground through pin K, which terminated at the ground junctions at the ICM mount bolt. I verified continuity between pin K and the ICM body, so electrically they are the same. I can only guess that GM noticed these plates got corrosion under the ICM body, so they ran a seperate ground for reliability.

Since my '93 ICM harness lacks the pin K (and grounding loop), I have decided to add a ground wire, tapping into one of the three ICM-to-pedestal mounting studs, and run the ground to the engine grounding point. Is it needed? Probably not. I clearcoated my ICM pedestal a few years back, so the grounding probably wasn't as good as it could have been (yet another reason why Jinx had "personality"), but should be worlds better now. Just as precaution, I will also be sure to add heatsink paste between the ICM and the mounting plate, as the pedestal doubles as a heat sink.

Second thing that will be getting my attention this coming week is the fuel pump. Both Don and myself noticed that the new fuel pump is a bit more current-sensitive than the old one was. You can hear the whine of it pitch differently in synch with the turn signals So, before I started the teardown, I measured the available voltage to it, and was a full volt lower than the battery voltage! Since I will be needing to wire in a new relay anyways, why not just make it a whole new wiring job as well? I am going to run a much larger gage wire to the back of the car (fused of course), to an aux. fusebox that will be located in the trunk. The relay will pick it up from there, and go to the fuel pump.


Quick Reply: OBDII conversion - troubleshooting time



All times are GMT -4. The time now is 11:51 AM.