7730 using $88 mask. 3.4 I've installed new injectors (Ford 302), changed bpw vs volts table and zeroed out bpw vs bpw table. I've also set the Multec fixing factor scaler to 0. Starts fine, runs fine until shut off, then won't restart until cooled off, like 30 minute. During no-start condition, has spark, has fuel pressure, doesn't have injector signal. I tested injectors both for ohm and amperage and are normal. The old injectors went back in, thinking I'll start over, but didn't revert back to old tune and same no start when hot condition, so now I'm thinking it's the tune. Is it possible to overheat the injector drivers with a tune?
It doesn't make sense to think the injector drivers are going into an overheat condition when the engine is turned off. They wouldn't be in the overheat condition when running since they work. For them to be in an overheat condition during a hot shutdown doesn't make sense unless something else is heating up the ECM.
Let's start with some troubleshooting.
Do you have the ECM wired to run the fuel pump relay? And does it work? That would be key on, before cranking, does the fuel pump relay and fuel pump come one for two seconds and then shut off? They should
Now just bump the starter. As short as you can make it. Does the fuel pump relay come on again and then turn off? It should That would indicate the ECM is getting the ignition signal. From the sounds of it this should work when the engine is cold.
Now start it up, and with the engine warm, does this happen again? It should.
Also if you have a scan cable, look for engine RPM during cranking. Then look again for this when the trouble is happening. Do you get it both times or only when cold?
At either your fuel pump socket, or at the oil pressure socket, jump the Orange/Black wire to the Tan/White wire. Does this help in the hot start situation?
How do you know the injectors are not firing? Noid light? Looking at the injector leads with a scope? Or just concluding it because you have spark?
A lower pressure but working fuel pump can cause vapor lock. Vapor lock would give the indications you describe. A too low fuel pressure pump doesn't activate the return line to clear out any fuel vaporization that might occur. Check for this by clamping down the rubber return fuel hose with a vice grips and seeing that the fuel pressure is 50 or above.
Have you tried a stock tune?
Have you looked at your TPS to make sure it isn't working wrong and the ECM thinks the pedal is floored? When this is happening the TPS scans at 0%?
[This message has been edited by phonedawgz (edited 11-05-2016).]
Sounds like you may have improper cold start values. If the chip programming has been adjusted and the engine consistently does not restart immediately after warm shut down that's probably what's going on. Been there and done it. Have you tried a part throttle start attempt? Usually programing in the fuel vs. TPS table, is set to increase startup fueling up until about 50% throttle with wide open throttle at startup being clear flood mode providing no fuel. When I've encountered this problem while trying to get the start fueling correct, I simply start cranking and gradually pressing the accelerator pedal down at the same time and if necessary doing it in reverse if I think the engine might be flooded, cranking with the pedal to the floor and gradually easing up. Bad electrical parts are very seldom consistent in their malfunction. If this is like clock work it's probably a tune issue especially considering the stock injectors did not fix the problem and they wouldn't if they flow even less fuel than your replacements.
Ok. After writing the initial post, I flashed the previous bin and ran to operating temp, shut it down, then started right back up, so it's definitely the tune. I ran a couple more heat cycled starts to confirm. I'll run like this for a couple days, then start reinstalling the injectors and change one thing at a time until it happens again so I know what it was. I'll report back with my findings.
Ron, the 19# injectors are over kill for the 2.8 or even a 3.4 for that matter. Even with the mods you've made, 17's might be too much. You would need to be over 150 HP to require an upgrade from the stock 15's. Not likely you gained 10 HP.
Edit: Just saw it was a 3.4. 17's should be sufficient for the V6. Remember the 302 produced a lot more HP with 8 cylinders and only needed the 19# injectors.
I may be able to get you some 17's that never made it beyond startups. Cheap.
[This message has been edited by fierofool (edited 11-05-2016).]
Originally posted by fierofool: Ron, the 19# injectors are over kill for the 2.8 or even a 3.4 for that matter. Even with the mods you've made, 17's might be too much. You would need to be over 150 HP to require an upgrade from the stock 15's. Not likely you gained 10 HP.
Yep, a slight bump in the fuel table for a little more fuel would be a lot better than an injector swap which can get very complicated in OBD I given the other tables involved that are often not adjusted along with base pulse width and injector size entry in code masks where it is actually used.
Originally posted by f85gtron: Ok. After writing the initial post, I flashed the previous bin and ran to operating temp, shut it down, then started right back up, so it's definitely the tune. I ran a couple more heat cycled starts to confirm. I'll run like this for a couple days, then start reinstalling the injectors and change one thing at a time until it happens again so I know what it was. I'll report back with my findings.
Your problem will be in one of the cranking fuel vs. coolant temp tables. When you made the adjustment for the higher flowing fuel injectors it affected the calculation in a manner that resulted in insufficient cranking fuel at the given coolant temp the problem occurred in. I haven't looked up the 88 mask, but generally if you go from 2.8L to a 3.4L, you should be able to run the 3.4L with the 2.8L code provided you have a proportional size increase in the injectors being used with the increased displacement. Changing the fuel flow and the engine displacement at the same time can complicate things. Swap the engine then take an organized approach to the tune. I believe in the past I have locked the BLM at 128 and watched the INT until switching to TunerproRT with a wideband O2 controller and using data log AFR averages to adjust. You also have to disable closedloop for tuning as well to prevent the ECM from making fuel corrections so that you can get it close first, and let the ECM fine tune The code masks are different in some of the same areas that seem pretty straight forward. In the code mask I run the fuel injector size can be entered but it is not used in calculations. The BPW table is where the adjustment has to be made for me.
[This message has been edited by Joseph Upson (edited 11-05-2016).]
$88 is similar as far as injector size items. They're more of a place holder and don't change any global fueling. Bpw tables are where global fueling changes are made. I'm now thinking zero-ing out the Multec scaler was a bad idea, combined with the low bpw table zeroed out and the tighter volts vs bpw table equaled goofy final bpw values for hot cranking. BUT, I didn't even think of hooking up the laptop and looking while the condition existed. I just went straight to assuming the drivers went to crap. Fierofool: I've built this engine with heavily ported intake and exhaust along with y pipe and upper plenum mods. The 17# injectors leaned out at higher fueling. The 19# are perfect.....providing I can get the ecm to run them better. My blms are finally in check and the o2 sensor is happily switching away. Have no fear, I'll figure it out! Phonedawgz: Thanks for the step by step clear trouble shooting recommendations. I performed most of those before I posted, but I agree with your opinion that the drivers where probably not overheating. Joseph Upson: Your post reply got me thinking about final bpw calc and what adds (or subtracts) into it to come up with it. I think that's why I'm experiencing this condition.
Thank you all for your replies thus far! I haven't definitively figured it out yet, but when I do, I'll post the results.
Originally posted by f85gtron: ... Fierofool: I've built this engine with heavily ported intake and exhaust along with y pipe and upper plenum mods. The 17# injectors leaned out at higher fueling. The 19# are perfect.....providing I can get the ecm to run them better. My blms are finally in check and the o2 sensor is happily switching away. Have no fear, I'll figure it out! ...
Your experience with the 19s kind of reflects mine. My 3/4 was ported to heck and back, ran a free flowing intake, headers and a 272 cam. I actually ran the 19s (Bosch pintle type) on a stock tune for a while. The only thing I really did (as a "temporary" measure) was to "open up" the BLM window, to allow the ECM to adjust to a wider range - mostly beneficial at idle. It ran so well, like that, that I never got around to actually tuning it properly, before I ended up selling it.
Thanks to all who've helped. I think I've found the problem, although I haven't been home to try the solution. Let me start by saying I'm an idiot I offset the values in the cranking pw vs coolant temp table....and guess what the value was for the last three cells? Yup, you guessed it, 0.00 msec. I think there's my problem. Not sure what I was thinking when I changed that table. Duh!
I'm running 17's with my 3.4.. Stock tune and adjustable fuel regulator.. Runs good, I think.. 260 cam
I thought i could get away with the stock 17#, but can't. They're pumped up to the limit (100% ve) before adders and they're still running lean (more than 150+ blm) on 70 map and above. The 19# allow the ve table to be brought down back to around 50%-70% duty cycles and consequently feel much stronger pulls past Redline to limiter. I'm also running the 260 cam, but with 1:6 rockers which roughly equals a 272 cam. I'm very pleased with the setup. Very happy with the torque and power. I suppose an adjustable regulator would've gotten the fueling squared away, but I went a different route already.
Sounds like you found this issue.. or have a good idea what cause it..
If that doesn't fix it, when it has the no start, remove the gas cap.. a faulty tank vent can and does cause this same type thing.. Might not be the problem here. but it might help others when chasing their tails..
SOLUTION: It was the suspected cranking pw vs coolant temp table. I reinstalled the 19# injectors and only changed the above mentioned table values to roughly 5 msec and VROOM! Cranked right up hot! Problem solved! Now I can get back to tuning.
