gcgarner

355 TPI has been in and running for a week now. I had a custom chip made, replaced knock sensor, and put in 24# accel injectors (and had chip programmed to suit). Everything else (other than water pump, belts, hoses, plugs, wires, distributor cap, etc.) swapped over from 305 TPI. Multiple problems have surfaced. I don't know if they are all related or not. I have addressed some of these issues on specific boards, but I wanted to post them all here to see if I could find some answers before I just go throwing parts at it.

Problem #1) Speedo worked for about 20 miles, then quit suddenly. I get code 24 intermittently, but speedo hasn't worked since. Cruise doesn't work either. Obviously VSS, but it tests OK.

Problem #2) Missing/jerking at idle

Problem #3) Strong gas smell after running (not from vapor canister ... can't actually pinpoint the smell.)

Problem #4) Gas is getting GUZZLED. Can't check my mpg due to speedo/odo not working, but needle is dropping much faster than it should.

Problem #5) Coolant leaking from pass. side dash. Heater core? But could this stem from or cause other problems?

Help?

gcgarner

Thanks for the quick response! LOL!

Had time to fiddle with the car today and here's what I've got:

I bought my chip from Harris Performance on ebay. It was the 5.7L "Hot" chip that came on a Moates adapter. I pulled the memcal/adapter/prom out, removed the adapter, and plugged the stock 305 memcal w/o adapter back into the ECM. Car immediately ran better. WTF? Missing at idle was still there, but it was a lot less (or not as noticable). Also, the strong gas smell was gone. The car ran great on a 10-min. drive and had just as much power as with the performance chip, it seemed. I know I can't run forever on the 305 stock prom, but if it runs better, what should I do?

Of course, the speedo is still not working and there is coolant POURING out from under the passenger-side dash. I will address those ASAP as I'm pretty sure it's simply VSS and heater core. I have a parts car I can get both from ... unless anybody has any other suggestions. The parts car is a 3.1 V6, but the VSS and heater core should swap fine, right?

Anybody?

TIMMYS89GTA

iTrader: (28)

If you still have the ecm in the parts car,try swapping it with yours.
I had a no speedo problem in my swap from 89 to 92 sd.after purchasing 3 vss's finally found that there was a problem with the ecm itself.
I too had a parts car with 3.1 eng. swapped the ecms and speedo worked just fine.
Anyway,coolant pouring from under pass. dash (YUCK!) deff. sounds like the heater core.Good luck man.

86z/92rs

Changing out the heater core is going to be a pain. Unless you have small hands, you will need to remove alot of items to get to the H/core.
As far as the chip goes, I would contact the company and explain to them the problems you are having.

gcgarner

Didn't think about swapping the ECM's! Thanks for the idea! I'll try to get that done on Monday. I guess both of those ECM's from my car and from the 3.1 car are interchangeable ... 730? Is that the right number?

I have already emailed Brian at Harris Performance Chips (www.tpichips.com) and told him my problems. Haven't heard back yet. Don't expect to since it's the weekend. But I wonder if the problems will correct themselves after the ECM swap? I am using my 305 memcal with the moates G1 adapter. Should I also be running a 350 memcal? I didn't think it mattered.

As far as changing the heater core, the tutorial on this site makes it sound so easy. I hope it isn't too bad. The great thing about having a parts car is that you get to try everything on it FIRST before you mess up your nice car! I destroyed a door panel on the parts car, but now I know how to take them off perfectly ... same for dash, console, fenders, etc. I plan on taking out that heater core 1st to see how it's done.

Thanks for the input, guys! I'll keep you posted. Any other suggestions, please chime in.

gcgarner

Swapped the heater core today ... easy? Not quite. What a PITA!! It took me forever and a crow bar to get the hose off the pipe closest to the distributor. The rest of it wasn't too bad. Even the "hard" screw on top of the heater box.

I'm swapping the ECM tomorrow. I hope that corrects most of my problems.

86z/92rs

Did you test the new H/core before putting it in? Hate for it to leak after all that hard work.

gcgarner

No. I didn't. Didn't even think of that ...

Hopefully I'll get lucky. But even if is a dud, I think I can change it out pretty easily now. The hoses should still be "fresh" on the core and a lot easier to get off. Needless to say, I didn't put that top screw back in my heater box .

Now, on to the VSS.

I took the ECM out of my parts car, popped in my V8 chip, plugged everything up and ... nothing. Car turned over and over, but no fire. Both are 730 ECM's . Plugged up my old ECM after changing the chips back and it cranked right up. What do I need to do to get the V6 ECM working with my car? Is it possible? Timmy, I noticed that your GTA is an '89 in your sig which means MAF and an ESC on the firewall. (But the car in your avatar has a 91-92 nose on it?) My car is 92 and SD (which means the ESC is incorporated with the ECM). Could that be the reason the ECM's won't swap? Is a 3.1 a MAF or MAP setup anyway?

Didn't get anything else done today. I was busy pulling parts off my parts car and fixing the hatch pulldown on my dad's '86 TA.

Still have the slight stumbling at idle. I'm thinking TPS or IAC, but I want to change the VSS first to make sure it's nothing to do with that. A tidbit on that idle issue that might shed some light for some of you ... if I'm driving normally and come to a stop, the motor nearly dies and the tach drops way down, then it kind of "settles in". I was going down interstate the other day, and when I came to a stop off the exit ramp it actually DID die but started right back up with no problem.

gcgarner

Figured out why the V6 ECM didn't work ... it was crap! That's the reason the parts car wouldn't run in the first place I believe. Oh well ... the search continues.

gmgod

The ESC circuitry for SD cars is in the MEMCAL itself. You should get an L98 SD memcal.

As far as the dying/idle issues go, I'd check/clean and lube the IAC first.

I'd also take a look at the speedo gears before dropping any cash on a VSS.

gcgarner

I was told it didn't matter. But that would explain a lot! Thanks!

I plan on doing that after I get the new MEMCAL installed. If that doesn't fix things, then the IAC is my next place to look.

Good idea. You can see the gears when you pull the VSS, right?

gmgod

I've been told it doesn't matter also, but I can't say for sure that it doesn't. I CAN say for sure that they're different though. Even still, I don't think that's the issue with the idle, it's almost always the IAC pintle getting stuck, or carbon building up in/around the hole.

And yeah, you can see the speedo gears when you pull out the VSS, the driven will be on the sensor itself, you'll have to look in the hole to see the drive.