91 Syclone memcal should be???

[nello]

I opened up my ECM last night because I'm still troubleshooting a rough idle. I figured maybe the HACK that owned this truck before me installed a chip. What I found to no surprise was that my ECM had been opened, wait scratch that, SURPRISE, its been remanufactured by BWD automotive. WTF. Next I see the memcal inside and it says BBZA 1576. I thought this was a late model typhoon chip, is their differences? I was expecting to see AYBM 4053. My truck runs but it idles like SH*T!

My questions are, is their another chip my vin 0985 SYCLONE should be using (whats the most current for a Syclone) and if this ty chip is ok what if any adjustments do i need to make to my truck, ie wastegate, ect. Any other Syclones using this chip having issues, idle or anything else, or am I the only one with problems, worse yet the only one using this chip?
:rant:

 

[sytyguy]

Re: 91 Syclone memcal should be???

That is a later model (Typhoon) calibration, but your truck should run fine (actually better) on that cal (than an early one.) The latest stock cal is BBZB-1580, but if you're not running right on the BBZA chip, it won't run right on the BBZB. Sounds like you have other issues.

The BWD ecm is merely a Borg Warner replacement ecm for our trucks. Look for a service code on the case so we can be sure you have the correct ecm in there (I feel sure you do.)

Sounds like someone replaced the ECM at some point and had a more current chip installed (either from GM or secondhand.)

Hood

 

[nello]

Re: 91 Syclone memcal should be???

Yes, the ecm does appear to be correct as I was able to match the correct numbers to it. So how bout a recommendation on a chip I could get with a stock set up. I want everything very basic. No fires please.

 

[sytyguy]

Re: 91 Syclone memcal should be???

Best option is to find a local tuner, but I remember someone saying they had a hard time finding someone in the Cali not too long ago.

Hood

 

[SBNova]

Re: 91 Syclone memcal should be???

Explain your idle issues. These trucks do not idle well, and there is even a reference to poor idle quality in the owners manual. Have you tried all the basic tune up stuff first? I would then check the EGR, and the IAC passages and clean them out with a good carb/TB spray cleaner.

 

[nello]

Re: 91 Syclone memcal should be???

SBNova -
Man I've tried it all except what will fix it. I did the full 60k tune up including belt, plugs, cap, rotor, and every fluid in that beast. Compression is good, I had one faulty fuel injector which I swapped which I thought was for sure the problem, did help a lot though. Then I some how passed my smog check even though I still had the idle issue. Checked my chip as you know abut am running out of ideas, hopefully getting closer to the answer though.

I took apart my boost guage today and found what looked to me like a crimped vac tube. I cut the kink out and put it back together again, so far a lot better idle but its still noticable. This is what I could see as being a normal rough idle compared to what I was getting. I'm driving it to work tomorrow for an extended test drive an I'll see what happens. I gotta look up more about fuel pressure and timing cause thats where I'm headed next.

 

[QUICK STORM]

Re: 91 Syclone memcal should be???

did you replace the ignition module? bad idle when hot or cold? what plugs? spark plug wire resistance good? good compression/low leakdown? how does the rough idle feel? broken motor mount/s?

 

[nello]

Re: 91 Syclone memcal should be???

Well the extendend test drive was sub par. Itsss baaack. Not nearly as bad as when I first bought her so I know I'm making progress.

QS, that's a whole lotta stuff. Tell me more about this ignition module, how can I tell if its broke. Same with the motor mounts, how do you verify you have a problem? I have issues with replacing things I can't verify are the problem first. Reason, I've already done to much of it. I do have good compression in all cylinders.

My rough idle is more of a tick. Not the sound but just the amount of movement. Goes from 7to800rpms back and forth really quick. You can just see the rpm needle moving back and forth rapidly. If I was to hold the gas down to say 1500 rpms I can feel a kind of shake in the engine. Its not major but it is noticeable. Like a lumpy cam would act, so I've been told but then was told by my mechanic the cam is fine. Truck seems to run strong with one exception, I can't seem to pin my boost during full throttle to any level of psi. (hence my question about having a typhoon chip instead of syclone's, wastegate need adjustments?) Boost shoots up to 10 or 11 tops, then drops almost to 0 just as quickly as it got there, even before it shifts. Truck is pretty quick but I'm not snapping necks so I know its not running to its full potential.

 

[sytyguy]

Re: 91 Syclone memcal should be???

Motor Mounts - Pretty easy to check. Have someone torque brake the truck while you stand aside the engine bay and look for the engine to "flex" more than usual. If you have a broken mount (most likely d-side), the alternator blade will come scary close to hitting the upper radiator hose (if not actually hitting it.) If that method isn't to your liking, just get a prybar or pipe and wedge it inbetween the engine and frame on the d-side and pry up on the engine (towards the p-side.) Look for lots of flex and you may even see the mount separate.

Ignition Module - Some parts stores have a free testing machine to verify the condition of the module. However, this isn't always reliable because some only act up under heat and use (which isn't always duplicateable (new word?) in a parts store.) If in doubt, change it anyways, IMO.

Have you verified that your WG rod is adjusted correctly? With the rod off and the puck pin pushed all the way forward, you should have 7/8 of the pin visible throught the rod hole. Basically, you have to just barely pull the rod onto the pin. If the rod is out of adjustment, any control issues will be amplified.

Hood