Help rookie with EFI conversion. Junkyard style

[dieselgeek]

Re: Help rookie with EFI conversion. Junkyard style

Looking at his log, I'm saying he has an external problem at the 3200rpm area. You can see the misfire in his tach signal, but the tach signal stays 100% tied to real engine RPM (i.e., no spikes or dropouts). There's no ripple in his other inputs either. I vote bad coil, or possibly power coupled noise in the coil.

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

Info sent Matt.

I'll look into the coupling possibility. Not much for electrical on this car, though. Manual fan, pump etc. Twisted the VR wires too. Have swapped the coil with no change. New cap and rotor will go on ASAP. Could the VR sensor be out of phase or something? Will also check the valve springs per advice from Scott. They are new, but you never know.


Helped a friend with his blow-through carb turbo Mustang tonight. Good to work on something familiar. ;D

Thanks

[Matt Cramer]

Re: Help rookie with EFI conversion. Junkyard style

Hi Sean,

Looking through the log, I don't see any sensor inputs going weird, and I'm even going to go so far as to say it doesn't look like a misfire. There's no short lean spike that would indicate this sort of problem. I'm going to say I think the problem is ignition timing related, though it may be retarded or advanced - either one can kill power.

First, I'd check to see if you are having VR sensor timing shift problems. Save your MSQ, then set the timing table to 15's across the board. Then check it with a timing light while free-revving the engine. Make sure the timing stays where it should be throughout the RPM range. A backwards VR sensor can retard the timing at high RPM.

If the timing isn't retarding at high RPM, though, I'd try backing off the spark timing in the 2600 and above rows. You're running a ton of advance. It's a rare engine that needs 40 degrees of timing at full throttle, but that's what is happening with your map. Even if it's not pinging, that much advance is generally not good for power.

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

Did as you suggested. Set the timing to 15*and checked, it did advance 3-4* with rpm. Could not see any other big changes with the timing light even when it was popping through the exhaust while free revving. Maybe the timing light isn't good enough? Was using the 40* in the tables just to see if it made a difference. Will pull it back down to 32-36* or whatever it likes.

I agree with you guys, think it is ignition based and not a problem with the inputs or MS.

Got fed up with it. Just started over with the distributor and ignition settings. Pretended I was starting from scratch. Pulled the distributor and checked it out and reset the advance plate. Moved a lot of the wiring around, redid the VR sensor position, redid the trigger offset, etc. Whatever was changed made a difference. Not sure if it is for the better or worse yet. Can idle and do light load driving so far. Will try to do more testing after work tomorrow.

Thanks Sean

[horsewidower]

Re: Help rookie with EFI conversion. Junkyard style

Don't feel bad, I've done the same thing a couple of times. I've found that we humans tend to over look things because... "it couldn't be that" "I know that is working right" "I've checked it a dozen times" "how can that be the problem"...etc.

Sometimes its best to just treat it as a new install and do it all over. I (or my obstinate friends) have yanked the complete wiring harness out my car twice.

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

I'm with ya. Have done what you speak of many times. :D

Well, whatever mental corner I had painted myself into is now solved with the last go around/piss fit with the ignition. I must had done something wrong the first time, because she is much better now. Managed to get a few datalogs recorded and used Megalogviewer to analyze them. Doing that and interpolating a few of the points on the tuning tables has the car running decent.

After much reading , and help/advice from others (thanks fellas), it finally feels like progress. Need to get some sort of Fidle or IAC on it for cold starts and when the A/C is on and do the finer tuning.

To summarize my second experience and first build with megasquirt: This has been a rewarding, but also one frustrating SOB. There is so much to learn for a non-computer type person it can be overwhelming. The terms used are alien, much of the info on the web seems geared to computer tech type people. Not necessarily a bad thing, but it does impose another hurdle to those that want to use the MS system that are unfamiliar with this stuff. Geek has alluded to the fact that installing and troubleshooting is the biggest hurdle to EFI. I agree with him. The tuning itself isn't that bad. Most carb guys could have someone show them the tables, what they represent and how to do some basic changes and they would be on their way, IMO. Just this evening, the tune went from a baseline to running better than it had with the carb in a hour. No mess, no fuss. Sat in the car the entire time. Not saying the carb couldn't run better than it did. Never took the time to dial the carb in, because the EFI was in the plans.

Will continue on with the tuning and be asking more questions, stay tuned

Thanks Sean

[dieselgeek]

Re: Help rookie with EFI conversion. Junkyard style

way to go man.

I think your summary is a good, accurate one. The worst part about EFI is the learning curve, and the troubleshooting. It's pretty easy to make a car run great once the bugs are worked out.

I am betting you have a phasing issue on the distributor. Big gaps cause big noise in the electrical system.


Anyways, do you think it helped having advice from those of us that have done it? I have somewhat arrived at the conclusion that it's easiest to do EFI if you have a friend around that's done it once before.

-scott

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

Oh yeah, the help from you guys is a big plus. The only thing better would have been having you guys here in person. Then this project would have went so much smoother and quicker, IMO. Most of this isn't super complicated, but is hard to grasp from text and being unfamiliar with it. I liken it to learning to tie your shoes from reading text instructions and having someone show you how to do it. It can be learned both ways, but one is a helluva lot easier than the other. ;D

This will also let me help on a friends 2.3T Ranger with MS on it. It has been sitting around with some bugs that need worked out because none of us really knew what to do with it. Maybe now we can get it dialed in better. That one needs fuel, ignition, boost, launch and nitrous control. From the frying pan to the fire, HA!

Thanks for all the help fellas

[horsewidower]

Re: Help rookie with EFI conversion. Junkyard style

Its interesting how often the problem is something we assume is done correctly. I went over to help a friend that was having a problem with his LC-1 AFR XD-16 gauge install. It was working correctly, then he and a friend tried reprogramming the LC-1 for a slower sample speed in order to get the gauge to quit being so jumpy. When they finished, the gauge didn't work. They relooked at the wiring, called the Innovative tech line, checked the forums and still couldn't get it to work. I looked at the wiring when I got there, everything looked good. I swapped in an new LC-1 and jumpered it to the gauge wiring, still just 3 blue lines on the gauge. We were about to take the gauge pod apart for me to check the wiring at the gauge and I asked him how exactly they had reprogrammed the LC-1 which requires them to unhook an input cable. They had swapped the output and input cables so it didn't work. It was a 30 second fix, its just they assumed that it was so easy and "hey how could we get that wrong" so they didn't check.

Wiring and debugging are the hard parts. The tuning is the fun part.

It's always helpful to bounce ideas off each other. And to remind each other to not assume anything.

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

The saga continues ;) Been playing with minor changes to the tune. Small changes here and there. The car runs well overall. There is still some tweaking to do down low, but very driveable at this point. The car doesn't feel more powerful than before, but smoother. Decided to go to the track again.

Went to Muncie dragway this time. Elevation is about 350 ft higher than the last track it went to and the weather today was miserable hot and humid. Guessing 20* hotter and much higher humidity than the last track outing.

First pass off the trailer was a 15.44 @ 91.XX. Damn! It does run better than before (16.055 @ 89mph ). No wheel hop, or drama at the line. No stellar 60's, 2.2's. Made a couple more passes with the car heat soaked and the A/C on and pulled down a pair of 15.7's. Did I mention is was freaking hot out? :D Let the car cool for a while and the temp came down some as the sun set. Went back to the line expected mid 15's. Ran a 15.18 then a 15.17 @ 92.81mph with a 2.177 60'. Better than I thought the much maligned smogger 400 would ever do. I thought mid to upper 15's would be it.

If the stars align right, the weather gives basement level pressure, some sticky tires, and the blessed Goddess of speed guides these mortal hands to perfect shifts, 14's might happen at some point. Not a fast car, but fun and I'm happy with it.

[horsewidower]

Re: Help rookie with EFI conversion. Junkyard style

Fantastic, good steady progress. Did you make any changes between rounds?

[dieselgeek]

Re: Help rookie with EFI conversion. Junkyard style

so, your EFI conversion knocked almost a full second off your E/T ?

nice, it means you are tuning correctly. Please tell me you datalogged your passes?

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

Only change made at the track was lowering the tire pressure. It didn't help much, but made the launch a little easier to manipulate. I'd say the improved tune gets much of the credit, pretty easy to get where it needs to be with the EFI. The carb was never dialed in, and probably would have improved at least some also.

Didn't datalog any of the runs. Should have, just didn't think about it. Can get the same data on the street if you want to look at it. From looking at previous datalogs, the kpa is going from 100 down to 95 as the rpm increases. I assume that means the throttle body or air filter is a restriction. Or is that not enough to worry about?

[dieselgeek]

Re: Help rookie with EFI conversion. Junkyard style

Only change made at the track was lowering the tire pressure. It didn't help much, but made the launch a little easier to manipulate. I'd say the improved tune gets much of the credit, pretty easy to get where it needs to be with the EFI. The carb was never dialed in, and probably would have improved at least some also.

Didn't datalog any of the runs. Should have, just didn't think about it. Can get the same data on the street if you want to look at it. From looking at previous datalogs, the kpa is going from 100 down to 95 as the rpm increases. I assume that means the throttle body or air filter is a restriction. Or is that not enough to worry about?

5 kpa drop would probably be 10-15hp, I think it's worth trying to get your WOT to be "atmospheric pressure" if at all possible...

otherwise, it all sounds pretty good. Have you gotten the cold starts dialled in yet?

[seanm]

Re: Help rookie with EFI conversion. Junkyard style

Have not adjusted the cold starts any yet. It starts well with what it has, but could probably be better. Still need to mount a fast idle solenoid, or put the IAC back on. Need to read up on that more too. Going to keep an eye out for a bigger 5.0 throttle body too.

Weighed the pig today, 4720lbs. Damn its heavy. Thats with my fatass on board, but still heavier than expected.