Linson

Stock L98, Scat Rods, KB Hyprtctc Pistons, Fluidampr, Cloyes Double Roller Timing, Edelbrock Vortec Lower Intake, Fast Burn Vortec Heads, Jegs 1.5 Roller Rockers, ZZ4 Cam, AS&M Large Tube Runners, Stock TB w/ Air Foil, Hypertech Cap/Rotor/Coil (black), MSD Wires (black), Accel 24 lb/hr Injectors, Walbro 255, Spectre Heated O2 Sensor, Ed Wright Chip, Dyno Don Headers & ORYP, Hooker Cat-Back w/ Monza Double Dual Tips, TA Performance Diff Cover, Alston SFCs, UMI Torque Arm, Hotchkis LCAs, KYB Shocks (black), one coil cut off front springs, ,SSBC Front Brakes, TransGo 2, Corvette Servo. Hawks Fiberglass Aerowing.

thats the car (89 Formula 350)and those are the mods. the car has under 34K original miles.

the car ran great with the Ed Wright chip, but i wanted to be sure on the fuel ratios and everything so i took the car to Blood Enterprises for dyno tuning and a custom chip (with live data logging). as it turneed out, Ed's Chip was pretty good and really close on the air-fuel ratios etc. car ran fine with the new Blood Enterprises custom chip for about two days, then the chip died. they sent me two more chips and after about 100 miles the second chip died. (car would barely run, run rough, run as if in some sort of "safety mode", car would smoke.) i called them and they agreed that there was a problem with that batch of chips. they asked me to instal the third chip to see if the car ran with it and it did. they sent me a fourth chip from a different vendor and it didnt work at all (same symptoms as the chips that had failed. i installed the old Ed Wright chip, and it now has the same symptoms as the other chips that failed. i re-installed chip number 3, and with that one, it runs, but idles at 1200 RPM, the fans spin up as soon as you turn on the ignition, and the check engine light stays on.

do i have a bad ECU now, or just a string of ****ed up chips?
i never had any issues like this until immediately after taking the car to Blood Enterprises for dyno tuning and using their custom chip.

also, as i laid out, chip number 3 isnt right, but has a different result than the other chips.

Linson

also, the check engine light blinks on then off (like its supposed to) with the three "car will barely run" chips. with chip number three (the fans immediately come on and car idles at 1200 RPMs chip) the check engine light is steady on from the time the ignition is turned on.

RBob

iTrader: (1)

Hard to say, but it could be that the ECM is bad. The one chip that turns the SES on solid and the fans on is definitely a bad chip.

The others that blink the SES at key-on, engine-off are OK. Or should be OK as long as the MaskId wasn't set to skip the check sum process.

Which leaves the ECM. The '7165 ECMs have their issues, and dropping it down and plugging chips into and out of it could have causes problems with it.

Only way to tell is to get another ECM.

RBob.

Linson

Where?

*edit*

nevermind. they sell them at Napa and O'Reilly's for $80.

talked to James at Blood Enterprises. he thinks its either the ECM or a bad adaptor plate.

Linson

*sigh*

okay. so i bought a re-conditioned ECM: no change. $80.00 down the tubes. James at Blood Enterprises sent me yet another chip attached to a new adapter plate. installed that: no change.

Question: can the factory prom be BAD? because the car doesnt run for **** with just the factory prom - which it should... a little rich, but it should run fine. outside of the ECM and related parts i cannot think of one part, electrical or otherwise that would cause these symptoms.

so, should i try to get a new/used APYU factory prom?

hrspwr

iTrader: (3)

I had a similar issue. Fan would turn on, stay on, car would run like a bag with a high idle. How do you change the chip? Do you remove the memcal from the ecm while the ecm is still connected to the engine harness? I had an issue where I burnt up a memcal doing it this way. After that I always removed the ecm from the engine harness then changed the chip. No hiccups after that.
You do not need a APYU memcal, you need a memcal from a 7165 ecm that has the same resistor packs as a thirdgen tpi. The APYU is just the code for the chip, but since you have a custom one, any memcal opens up a few more doors.

Tuned Performance

iTrader: (92)

you can use any tpi memcal from 86-89 if your just making use of the I/o and netress. Or for that matter use a 3.1l memcal from a 730 ecm and solder in a jumper for cylinder select.

Linson

the first time, i removed the ECM. the second time, i just pulled off the chip through the little plate covered opening, with the ECM haning down from the under-dash. i also ran a series of tests, testing each of the five or so chips i had acquired at that point, in the same manner, through the plate covered hole with everything connected.

on eBay, i see memcals for sale from anywhere between 80 and 300 bucks. they typically advertise as having been "tested and in good working order." how do you test one of those, so i can determine if mine is bad before buying a replacement?

thanks.

hrspwr

iTrader: (3)

As I said I had that issue. Going forward when changing the prom or removing the memcal from the ecm, always unplug it from the harness first....I learned the hard way as well.
On the memcal there are three chips. One is the prom with the tune and the other two are resistor packs, which have a series of different resistance values. You would need to check to make sure that each value is correct with a DVM OR put it in a working ecm and make sure it does not experience the same issues you are facing.
Talked to Tuned Performance, he may be able to help you out.

Tuned Performance

iTrader: (92)

Im sure Esd will kill a memcal. The only difference in some 89 memcals they use a different limp home resister network. I do have a few tpi maf memcals but I'm not sure if yours is faulty. fans running or lack of ecm comminication bye entering in field service mode could either be the ecm or memcal.

Linson

Esd? Electro-Static Discharge? hmmm.

the thing is that i dont always get the same results. for example, with one of the chips, the fans spin up, but with the other 3 or 4 they do not. with the chip thats in it now, it varies (which seems really strange.) the reason i'm thinking the mecal may be the issue is because the car has the same symptoms as with the majority of the chips when i try to run it with ONLY the factory prom (Memcal).

also, i have replaced the ECM which netted 0.0 results.

so, it has

new ECM
new adapter plate
has gone thru several different prom chips

therefore im thinking its the memcal or an ECM wiring issue.

what do you think?

Tuned Performance

iTrader: (92)

Electro-Static Discharge yup, It could be a maf issue but the only way to see what the ecm is seeing is to use a scanner or datalog. You might want to post in your region there maybe a member with a 86-89 tpi that wouldnt mind swinging over to let you use there memcal with your piggyback to see how your car runs.

Linson

okay...well, funny story. here are the facts

1. about three weeks before taking the car to Blood Enterprises i installed an SLP CAI that i bought from another TGO member.

2. before putting the CAI on my car it required extensive cleaning and a coat of paint.

3. the car ran great with the CAI for three weeks before taking it to Blood Enterprises, and ran great for a couple days after taking it there.

4. the first chip (i think) did go bad, OR the problem i'm about to describe manifested itself then unmanifested itself, and or an air intake blockage can cause the car to mimmic ECM trouble (fans coming on, no check engine flash, ect.)

5. after replacing seveal chips, an adapter plate, and the ECM box, i had my buddy come over with his scanner to run some tests. we were getting readings that didnt make any sense really. HE TAKES OFF THE MASS AIR FLOW SENSOR, AND I SEE A BUNCH OF LITTLE TORN UP PEICES OF BLUE MASKING TAPE STUCK TO THE SCREEN (the same blue masking tape i used to mask off the air box lid when i painted the CAI.) i removed the air box to MAF tube, and right at the air box end of the tube and THERE'S A BIG WAD OF BLUE MASKING TAPE, BASICALLY BLOCKING OFF THE ENTIRE AIRWAY. car ran fine after removing all that tape.

the only mystery is what the hell happened (i specifically remember being very careful to NOT leave any tape in or on the parts), and how did this issue not manifest itself immediately after installing the CAI?

the good news is that the car is running great and i finally get to drive it with the badass new thick leather steering wheel.

Tuned Performance

iTrader: (92)

Glad you got it fixed, never would of guessed tape in front of the maf lol

Linson

yeah, i never would have guessed that either. when my buddy, who is a mechanic, comes around, i generally get good results.

when i got the car back from having the engine built back in 2011, the engine ran strong, but it idled horribly, had no vacuum for brakes, and the idle speed was about 40 MPH. the mechanics at the shop swore up and down that it was all because of the "massive" ZZ4 cam. same thing, had my buddy come over with his scanner and timing light ect. after hearing it run, he starts spraying carb cleaner around the engine and he says "you've got a vacuum leak." he isolated the leak to either the TPI runners to the manifold, or the manifold to the cylinder heads. hoping for the best, i ordered new runner gaskets from AS&M, took the runners off (had them powdercoated) and reassembled, and the car ran great. ran like a normal car: smooth idle, had brakes, normal idle speed.

fact: im having a dinner in the guy's honor tonight.

Darren1

Thats funny, maybe I better look in my intake, I am having issues as well. lol Enjoy !! I am running out of time to cruise before winter comes and Miranda goes back in storage for the winter.

Linson

Examine the MAF Sensor if so equipped.