Hey guys, I'm beating my head against the wall and need some help, or even a direction to start looking..

Background - It's a 3.4 DOHC from a 93 cutlass supreme in my 86 Fiero. Main reasons for using the $58 code is that it has a T3/T4 hybrid turbo and I am going to use the $58 stuff on my Z28. Engine is stock except for the modded ford 19lb injectors that now flow 28.2lb/hr. Also, new plugs, wires, intake gaskets.

I dropped the engine in and wired it all up.. (wiring in next post) Modified a prom carrier to have a ZIF socket with an AT29C256 which is programmed with a stock $58 bin that I modified.

As per Grumpy's instructions, I changed the spark ref angle to ~60 deg and modified max retard and max adv.. I also changed the spark table and a few other things that I don't think would have much imapact on starting..

Now, here are the steps I went through..

Turned on key, fuel pump came on, then went off.. That's a good sign.. Crank, crank, crank, crank, crank.. Nothing.. It has been sitting in a junk yard for a while, so I was sure it wouldn't start right up.. No backfiring either..

Next, I took the plug off of the crank sensor and used my test light to simulate the crank sensor.. Sure enough, the fuel pump turned on and the plug I had out, and on a wire, was firing.. That's good..

It seems like it kicks sometimes, but not consistantly.. After cranking I pulled the codes and it gave me a code 51.. (bad eprom etc) Sure enough, I ASSumed that Programmer automatically recalculated the checksum when you save the bin.. WRONG! /sigh..

After loading it back up, I tried again and after some cranking, it started and ran for ~2 seconds. Didn't really run rough or anything, but the SES light was on.. I was able to get it to start and run like that 2 more times, but that was it.. Mostly just cranking.

I checked the codes, but got nothing! I didn't have my laptop so I couldn't hook it up to check it out..

Any help/ideas would be greatly appreciated.. I'm running out of stuff to try..

Thanks!

 

Here is the pinout that I'm using

 

One thing I forgot to mention, I don't have a CTS hooked up yet for the ECM.. (lack of mounting location).

Cheers,

 

The CTS is the single most important sensor for cold starts. And why in the world would you eliminate sensors and expect things to work out?

RBob.

 

It is by no means permanent, I actually forgot that it wasn't installed till just now..

Do you really think that it would have that large of an impact as to cause it not to start at all?

A quick and dirty solution I guess would be to hook the sensor to the connector and just let it sit on the engine just to see if it makes a diff.. Ambient temp and engine temp should be the same for initial startup I would think..

Thanks!

 

Turns out I must have thought the same thing.. I left out the CTS sensor for the gauge, not the ECM.. Just for fun, I tried another sensor I had laying around with the same results..

Beats me why I thought I left the one out for the ECM.. Didn't make much sense..

Thanks for the thought..

 

Have you adjusted the BPC vs. EGR table for the new injectors? When I first tried to get my car running, I had a similar situation as you describe. (Although, this was a TBI V8 ) I was running into a situation where the crank AFR was set rich enough to get the engine to run. After the engine was running, the AFR was "leaned out" to whatever was cal'd for an engine running state. This would cause the engine to ultimately die. In my situation, it was a little easier to see the injectors squirting less fuel as the engine ran for those few seconds....

So, if you haven't already (you do mention a modified $58 bin), I'd suggest "richening" up the BPC value to see if that helps...? And/or a quick-and-dirty trick without reprogramming would be to see if the engine will continue to run by sparingly squirting some starting fluid? At least it would tell you if the problem probably lies in the fuel system or not! And, now that I think of it, can you put a gauge on the fuel rail to make sure your pump is working as expected after the engine is running?

Another possibility exists in the knock sensor subsystem. I don't know if all 749/$58 behave similarly. But, I notice my knock counts seem to go kind of crazy with the engine just sitting and idling (and not knocking). Since the car hasn't made it off the jackstands yet, I've just calibrated out the knock sensor until I have more time/motivation to tear into it further. Maybe you're running into that, too?

Finally, have you checked that each of the sensors (TPS, MAP, Coolant, IAT) show reasonable values with a scanner at any point during your installation? (I know you mention you didn't have your laptop in the first post. But, maybe you checked this stuff out at an earlier time?) Sounds like you are in a similar situation as I was in that there was quite a bit of new/modified wiring added to the vehicle. I even managed to wire up the TPS "backwards" on my first attempt. While I caught this before the first start, I would imagine it would have been difficult to start for the first time in a perpetual clear flood mode!!

Well, I know I said finally. But, another thought occured to me while typing up the rambling above. Are you certain the IAC is wired up and operating correctly? You might want to run through the Idle speed / IAC reset procedure to make sure the IAC is working as expected. I wouldn't imagine the IAC would cause all your starting problems all by itself. But, it definitely could contribute if there are other "little" problems like it floating around.

Let us know what you find.

 

Thanks for the reply 1981TTA, I appreciate all the help I can get.

I didn't touch the BPC vs EGR table at all.. I think the sy/ty's come with 30lb injectors, which wouldn't be too far off my 28.2's.. I will try messing around with them after my battery charges back up..

I had all intentions of bringing the fuel pressure gauge home from work today, but forgot all about it..

If I could get my laptop to connect to my ECM, I could see what the KS is doing, maybe I'll just reduce the max retard to 0 for the time being..

I was trying to use my laptop with TunerproRT and my 2 transistor cable, but to no avail.. I know the cable works as I was using it with WinALDL. I'm going to do a search and see if anyone else has had this problem..

I've triple checked the IAC wiring (but that doesn't mean it's right, lol) but haven't checked to make sure it's working correctly.. I did have it out and blasted it with throttle body cleaner when I had the intake off..


Here's the current situation.. I tried starting it tonight pumping the throttle as the engine was turning over.. This seemed to get it to start and if I played with the throttle it would stay running for a while.. It doesn't help if I just hold the throttle at a set position.. (weather it's wot, or partial)

Will the ECM look at what the TPS is doing during startup? If it was actually giving it "pump shots" that would mean I need to add more fuel, which would at least be a dirrection to get going in.. I also don't have any starter fluid, or a second person handy to crank while I spray..

Thanks!

P.S. - Still no DTC's from ecm..

 

I'd suggest doing this in the short term just to make sure it's not getting in the way. Once the engine stays running and you can connect via ALDL, you can confirm what's going on.

My personal experience with the 749/$58 is that it's very touchy when trying to initially connect to a scanner. I've had good, consistent results with Tunerpro and Datamaster. But, I'm also using a MAX232 interface.

This sounds a LOT like how my engine behaved before adjusting the BPC table. If the engine is considered "running" by the ECM while you do this, there's a good chance the AFR is being modified (likely adding fuel) due to pump shot (Accel Enrichment) algorithms. If the engine is considered to be "cranking" by the ECM, TPS is only used to determine whether or not the AFR should be reduced for clear flood mode. AE algorithms won't be active under that condition. However, any changes in MAP will potentially change the VE calculation during this time. Granted, this shouldn't be a big change. But, there could be some influence.

From what you describe, it definitely looks like a bump in BPC is going to get you going...

 

you spark ref angkle should be 10btdc not 60*. the notch on the 7 tooth wheel for tdc that the module uses to generate the ref pulse spits it out at 10btdc. now on a 3.8 liter yes then that modue refs at 60btdc. try that and get back to us.

 

I've got some MAX232 chips laying around here, I'll make up a new cable and try that..

I did try a new BPC last night of .081 (Guesstamate), but it didn't help at all, actually made it worse I think..

Funstick - The reason I used 60* is because that is what is used in a stock bin for the 3.4 DOHC.. From what you say tho, it sounds like 10* should work..

Thanks guys!!

 

Woot! Alright, here's the story..

Reverted to my original modified bin and set the timing to 10*, rolled it over for a bit, nothing.. Changed the BPC to .072 and it fired right up and ran without using the throttle..

It's got a rough idle, idles around 600rpm and pops out of the exhaust every other second (open manifolds, not putting the turbo on till it runs a little and gets all the dirt and crap out).. SES light went out too after it started..

Now to get started on my new ALDL cable to see what's going on..

Thanks a million guys!

 

Care to elaborateon how you modified your injectors?

 

Sweet!!

Just as a coincidental experience.... I'm currently in the process of getting my ECM bench back up and running after a 3 month hiatus. After all this time, I don't remember all the reasons I left things the way they are. But, (and here's the interesting part) I'm feeding the bench with a crank signal and getting the following behavior : fuel pump on, injectors firing, SES light always on, nonfunctional ALDL, fans commanded on. If I read your first post correctly, this sounds almost exactly like what you were experiencing after correcting the MALF 51 problem. Effectively, this is limp-home mode. I'm willing to bet there was a problem with the way the chip, or chip assembly, was installed in the ECM. During the process of removing/replacing the EPROM while making the BPC changes, it sounds like things were corrected. If you haven't tried the ALDL since getting the engine running, I'd give it another try to see if it doesn't magically start working.......

 

BMmonteSS - A fellow I know has the tooling to do it.. Unfortunatly it's a tightly kept secret and he won't let me in on the details.. I know it involves taking the injector apart to a certain extent and making a bigger orafice in the restrictor plate. He can turn 19's into 28's, 30's into 42's, etc, etc.. He also has access to a flow bench to make sure they're all within 2%.

1981TTA - Yea, I'll give the logging another try, thanks again for all the help.. I'll post my results.

Cheers!

 

glad to hear it. while the notch one the crank are 60* apart the 7th notch the sync notch is 10btd on cylinder number 3. i checked yesterday just to be sure.
once you get the turbo on and some back pressure to the exhuast manifolds youll probably need to richen it up a bit down at idle but im glad to hear about the sucess.

 

Right on, thanks for checking that out.. It's all coming together..

Cheers,