I am at my wits end here,,, I can not figure out why the ECM will not go into PE mode for me even though the TPS is reading over 4V. PE mode should be triggered when the TPS is 70% (what ever that is) or higher, but I am sure that with the TPS reading over 4V should qualify.

So failing to figure this out, what other aftermarket EFI can I install?

 

I am not familiar with your set-up so excuse my ignorance in the next couple of questions. What ecm are you using? How do you know you are not in PE mode? Does your data stream not show tps%?

 

I am running the factory ECM still in my '87 Camaro IrocZ. So its a 165 ECM using the $6E definition file for '89 Fbodies. I do "burn" my own Eprom chips. Its a MAF car. I have a wide band O2 meter setup, while at WOT the O2 meter is reading from high 13s up to mid 14s to 1 AFR. The TPS% is not in the data stream. So I have no idea what the TPS% value is. Since I am seeing high AFR for WOT, I am assuming that the ECM is not going into PE mode. RBob has stated on the DIY Prom board that the ECM is seeing a high TPS voltage and that the ECM is ignoring that high value and thus, not going into PE mode.

I have one more thing to try, that I have thought of. That is to set the TPS voltage at idle to about 0.45V... Another thing would be to install a new TPS sensor and see if the range of volts is less than my factory TPS.

Any help is appreciated.

 

Well I would say to stick with your ecm for the original question. If you had to I would go to the EBL. Or go with the 411 PCM with CNP. Quite frankly I am biased towards the GM ecm but anything out there that isnt GM is going to cost quite a few bucks and is going to have a learning curve anyhow. Now onto getting the problem solved if I can! Obviously you could have a mechanical problem and not a software problem. A bad tps, a bad wbo2, bad fuel pressure, whatever. That I cant help with and it cant hurt to double check everything. As far as what the ecm is doing or not doing let me ask a couple more questions. Are you running closed loop or just using the wbo2 for tuning and leaving everything open loop? I ask cuz I seem to remember that PE is still considered closed loop but the INT locks at 128 with the saved BLM from that cell. So if you are running closed loop watch for the INT locking at 128 and that might be evidence of PE mode. At what tps% do you have PE set for? You can set it farely low or high. Also, how far have you modified the prom to account for the maf maxing out? My experience is with SD but I remember a lot of the MAF guys had to add plenty of fuel via PE in order to get enough fuel in once the maf maxed at 255gps. Looking at your sig, I would say you are flowing quite a bit of air. So if your PE is set on the high side and your MAF is already maxed out, this might be part of the problem. And it cant hurt to ask on the DIY-PROM board for help on getting the tps% into the data stream. It would require you to edit the data ecu file but it shouldnt be that hard for someone who is familiar with your data software.

 

I am running whatever the ECM will go into,,, therefore, after warm-up, the ECM will go from open loop to closed loop. I am running my Mega-MAF which is the electronic guts of a stock MAF stuffed into a 3.5" OD aluminum tube. The six MAF scalars and each of the six tables had to be adjusted big-time to account for the extra flow. All of us with MAF cars have always maxed out the 255 gms/sec limit. But once the ECM goes into PE mode, we can account for more fuel thru at least two different tables, PE vs RPM and PE vs coolant temp. It is these two tables that I believe that the ECM is not using now because my AFR has changed from high 12s to the 14s while at WOT conditions.

 

Look at this www.DynamicEfi.com. I run this setup on a Ramjet 350.You would have to repin the ECM plugs, but I think the 165 ECM plugs are the same. And you tune speed density, so you can lose the MAF. Also, if you'r used to burning chips, you'll love the flash feature. One more thing, if you go this route, you will need the port injection mod done to the ECM. Plenty of support here too. Hope this helps, Dean

 

I see. So this is a new problem or in other words, the ecm and software were functioning fine once upon a time. That usually indicates a mechanical problem. BTW you can change the amount of tps% needed to achieve PE so just for grins and giggles why not change it from 70 to 50 and see if it helps. Also have you recently checked the fuel pressure or do you know the fuel pump is delivering the necessary fuel. Varying afr's signals fuel delivery problems. I did check out your thread in the other forum and saw what Bob replied so did you try to find the thread he referred to?

 

I did a search and found a post or two by RBob on this matter of too high TPS voltage readings. Also, I have a new bin file put together which lowers the TPS% to invoke PE. I have not had a chance to "burn" it yet.
Let me see if I can recall some events in chronological order:
1)With the 395 stroker and SuperRam, car runs a 12.12sec ET at Milan, Mi. AFR in 12s. Tranny shifts very firm. Car pulls 340RWHp on chassis dyno.
2)Same above, car runs mid-12s at Orlando Speedworld, 60ft time is to blame. AFR in high 12s. Tranny shifts very firm.
3)Swap out to HSR last Spring. Install 30#/hr injectors. Program Eprom for 30#/hr injectors. Car runs mid-12s again. Tuning to blame here, maybe. Tranny shifts very firm.
4)Around September, wide band is showing high 13s and 14s at WOT, tranny will not up-shift @ 6000RPM anymore, engine hitting RPM limit of 6800RPM. My thought is that the engine is running out of fuel at WOT.
5)Walbro fuel pump installed around Thanksgiving. AFPR set at same fuel pressure.
6)Car pulls 340RWHp on chassis dyno; fuel pressure increases 4 to 5 psi at WOT, just as it should. Idle FP @ 40psi.
7)AFR still in the high 13s and 14s at WOT, tranny still wont up-shift properly.

I am having two issues, and I am not sure if one is causing the other. I am thinking that since the engine is running very lean, there is not enough line pressure (or whatever) to get the tranny to shift as before. So I am thinking that if I can solve the issue that the ECM is not going into PE mode, then I might solve the tranny up-shift matter as well.

 

I would think the trans matter has nothing to do with the PE thing. Line pressure is related to RPM and the trans oil pump and regulator. Shifting is done by the TV cable and the governor. Changing the intake may have effected the TV cables adjustment. Now if the car made the same power as it once did with "indicated" higher AFR's then maybe either the wbo2 is bad or it actually likes that AFR? I am just guessing here you know. Just trying to throw some ideas your way so dont take anything I say as matter of fact. Now I have another question. I would guess that you've moved from MI to FL. I would say that weather conditions from one place to another are almost complete opposites. Is it possible that the blm's have moved around on you since you moved? I ask cuz as I remember the BLM is stored for WOT to be used in PE and the INT is locked, at least in 8D 730. I noticed in the data screen shot you posted it showed the BLM at 128 so either the calibration is extremely close or the PE is not using the learned BLM and this may cause a lean afr at wot. Did you notice any difference in the way the car ran? Just another shot in the dark here. Maybe the original re-calibration to the MAF needs to be tweaked for the change in climate and baro pressure. Do MAF cars have baro or map sensors?

 

3rd gen MAF cars do not have a MAP sensor. Another thing is that I have always tuned the "drive around stuff", read as = part throotle, by watching the BLM value in each Fuel Trim Cell (FTC) and adjust the MAF tables to bring the BLM close to 128. Since I have been running my MegaMAF, this is the method that I used to calibrate the MAF tables. Now most recently, and around the time of my problems, my MegaMAF took a dumper. I created a new MegaMAF but this time used the flat board type MAF electronics. I have several experiments to run now. One is to install a regular MAF again and see what the ECM does,,, I will need to go back to the stock MAF tables for this test. Also, I can set the TPS at 0.45V at closed throotle and see what whats then. Time to get going.

 

First experiment is a bust. With the TPS set at 0.45V, and the engine warmed up to above 160*F for coolant temp, the ECM will not go into PE mode.

 

This is really fustrating!!! I kept the TPS at 0.45V at closed throotle, as above, and reinstalled a factory MAF along with a matching calibrated Eprom. The ECm still will not go into PE mode. And also, the tranny wont up-shift as before, I'm hitting the rev limiter set in the Eprom.

There is a question above that the wide band might be bad. The only thing that I can say is that it reads right around 14.7 at idle.

Does anyone have any ideas for me?

 

This is interesting. Are you using the expanded $6E xdf? make sure there are no flags/constants/switches set that are disabling the PE mode, but i'm sure you have looked into this

If it worked before and now does not...then sounds like something mechanical or electrical went bad, like a sensor or something.

Tranny also sounds like its going out...either slipping clutch packs or something with the TV cable? Not sure how that could effect PE mode tho, and probably doesnt have influence on that.

Could always try a 730 ecm speed density swap

 

Orr: glad you saw my post. I got two more posts on the DYI Prom board. As you already know, I have the 165 ECM, but using the '89 $6E definition file (mask). I do not know what "xdf" is. I have looked thru the entire bin, trying to find something that would prevent the ECM from PE mode, but only see a value for TPS% which invokes PE. Since I dont have the value for TPS% on my scanner, I am at a lose here. The bin is set at 70% and now I have moved it down to 60%.

Also, I have considered switching to the 730 speed density system. But I would prefer to find out whats wrong with my MAF ECM.

However, even though I am saying that the ECM is not going into PE mode, the engine will easily leave a major tire patch on the road, this is with P295/35R18 BFG Drag Radials on the rear. But then I hit the rev limiter, and the engine quits running for a sec and all momentum is lost. (Mo goes out the window!)

Please fill me in on xdf.

 

You using tunerpro?

xdf is just the definition file to read the 6e mask. There was an expanded definition file made for the 6E that has alot more tables/constants/etc in there to play with. Some you dont need to do anything with but some are nice. Its been alittle while since I've played with 6E tho and I dont have access to my old 6E tunerpro files until this upcoming weekend. I dont think I have them on this computer but may have them on disk somewhere.

Latest tunerpro RT version I think uses a different file name than xdf but does the same thing.
I dont remember what my 6E stuff captured in the datalogs but i know they had tps voltage available and from that you can get a rough idea what percentage you are at. I am not sure if there is a TPS % column of data in the datalogs.

Being that lean you are still going to make some power. In the 14's to 1 is lean for WOT but still going to make some power so its going to spin some tire.

Double check the wideband is still operating correctly to rule out a miscalibrated sensor.

Also check to see if there is a minimum LV8 to enable PE mode. I remember one of those being available. If you want, you can send me your bin and I'll look through it if I have the tunerpro files on this computer..I think I do.

 

I am now using Tunerpro because it makes the MAF table scalars available to me. I used to use TunerCat, but that tuning program did not have the MAF scalars. I need the MAF scalars to tune my MegaMAF (we have discussed this before if you recall a couple years ago). I am not using TunerPro RT.
What is LV8? is that "engine load"? I am still using my ancient AutoXray 240, it has engine load, and TPS voltage. How does the ECM calculate TPS%? My bin for the MegaMAF has LV8 = 66 for PE mode, while the bin for the regular MAF is set at LV8 = 74.
The wide band is saying I am at 14.7:1 or close when I am idleing the engine. I guess that I could stick it into my '99 car and see what it reads at WOT.
I will send you a bin file via email thru thirdgen if I can.

 

At this point my question would be: is the ECM really not going into PE mode?

The easiest way to tell is by observing the commanded AFR via the ALDL stream.

RBob.

 

Ok, was doing a lil researching for my own car and ran accross an issue that maybe has something to do with what you may be seeing or experiencing. It seems that the CCP may have something to do with keeping a car out of PE although this was on a 7730 8D car. Anyhow, if it is disabled or not disabled it may affect the enabling of PE. This was on the tuning guide for 730 under "stuck in cell 4". Here is the link https://www.thirdgen.org/forums/diy-...-cell-blk.html . Grim Reaper about 1/4 of the way down refers to what I'm talking about.


Also, do as RBob says and try to verify that you actually aren't in PE. Maybe you should give the data software I use a try since it is just a step above the autoxray you use. ECM852 from moates has a .dat file for the 165 MAF cars and tada!, it has TPS% in the data stream. It is still available for download over at moates.net and has to be used with win98 or less or even DOS.

 

RBob & hectorsn; thank you for your posts, I think that will be most important. What is CCP? Another thing, when I was adjusting the TPS with the key on, I heard a motor whine from the cholcoal (sp) canister. So is CCP Chorcoal Canister Purge? I have never heard a whine from the chorcoal canister before in 23 years with the key on, engine off.

Now for this:
STUPID STUPID STUPID me! I solve the tranny up-shift problem. I had replaced the factory rubber type rear tranny mount with a ployeruthane unit from Suspension Engineering. The new mount raises the end of the tranny about 1/2" or a bit more. This in turn threw the detent cable adjustment out of adjustment. All I had to do was pull the detent cable forward thru its bracket about 1/8". Sometimes I am my own worst enemy. Now I can concentrated on determining if I am really not in PE mode when I should.

 

Yep, charcoal canister purge=CCP. Its a shot at least. Try to search "ccp disabling pe" or something. Also, take a look at ecm852 for datalogging. Its old but works quite well at least for me since I just look at numbers. Graphs and dashboards do more to confuse me. Its also free and can be adjusted to your needs with some goofing around of the .dat file.

 

Sounds good, I will read up on the matter. I might find the answer to this question, but what do you think is this buzzing sound that I hear at the charcoal canister? Is this canister trying to conduct a purge all the time?

1st EDIT: OMG! that thread is from 2003! what worse is that I'm mentioned in it. Too funny!

2nd EDIT: I think that its best to start a new thread on the CCP stuff.

 

I'll take a look through my old 6E stuff to see if thats in there but I never had any problems with PE mode, but I always had charcoal canister and never played with any of that stuff. I'll take a look at your bin if you did email it to me, i havent checked yet

 

Doc, i dont see anything in your bin that would keep it from getting into PE mode. My 383 bin used 50% TPS for pe enable above like 3200 rpm or so, and 70% at 1200 rpm, so you dont start getting into PE while light accelerating. Best for fuel economy but that isnt causing your problems.

I'd verify its not going into PE mode by using some sort of scan tool. Tunerpro RT is nice setup and can tell you alot more variables than hand held stuff. I think there is a flag for PE mode that you can see when datalogging so that will indicate if your in PE mode or not.

CCP settings i saw are similar to my old bin and i never had a problem. I had the canister on my car and it worked fine from what i can tell. So I'm not sure what else to look for.

 

Orr: Thank you for getting back to me. There is one thing that I need to clear up, and that is the whining noise that I hear when the key is in the ON position. I heard this noise when I was setting the TPS voltage. Also, I will look into getting TunerPro RT, if its got scanning capability, then its probably better than my 12 year old AutoXray 240.

 

Update: I believe now that the ECM is going into PE mode because my scan tonite shows that the BLM and INT are both locked to 128, and I think that this only happens when the ECM goes into PE mode. So now its down to a bad wide band O2 meter setup, or for some reason I am not getting the fuel delivery that I got before the swap to the HSR, or I am truely getting enough additional air that the engine is now running lean. I did install a new 255L/hr fuel pump and have confirmed that the fuel pressure rises about 6 psi at WOT VS idle.

 

Did you check to see what the commanded AFR is on the scanner like RBob suggested. When in closed loop my 730 reports 14.7, while at idle in open loop it says 14.2. The commanded AFR is a pretty good indication of what the ecm is thinking.

 

My crappy scanner does not have the commanded AFR in the ALDL stream I will have to acquire a new laptop and software to be able to do that. Or is there an easier way?

 

Moates.net ecm852 should work with what you have. He made it back in 2004 I think, maybe earlier. It works on my old laptop with win98 and a serial port rs232 driven aldl communication device from akm cables. Probably the same thing you have for hardware, right?

 

You are right; my old laptop is Windows98. Thank you for the tip.

 

Update: I tripled the values in the "PE versus RPM" table, and now I see a high 12's and 13's for my AFR. So, apparently, I am not a very good judge on how much to alter that table and the resulting AFR. Another lesson learned here. I still need more fuel at and above 5,000 RPM, so I will burn yet another Eprom chip!