The factory specification for most TBI engines is ZERO degrees BTDC.
The VSS has caused some debate on the board over the years. Most members agree it not NECESSARY. Most members agree it NICE to have. Some members have reported unexpected stalling was NICELY eliminated with adding a VSS.
dave w
Hey, Davew -Originally Posted by dave w
re: timing - have had it all over the place; in talking to AFI, they said, given my setup (separate distributor w/ICM & coil) vs. ECM-controlled spark, that 0 BTDC wouldn't work for me. I had it there for a while back last Fall & saw severe power loss. Truth be known, i've had the timing all over the place, 0, 5, 10, & 15, and saw severe running issues everywhere but 10. A few people over on the FSJ forum recommended 10, and it's run the best there. Eventually, i tripped across an original emissions sticker that showed 10+-2 at low altitude.
re: VSS - will take a look at that & see what i can find on the forum. Hadn't seen anything about that. Am assuming if i did something like that, that i'd need a new chip burned to account for it, true?
Today, i pulled & attached a 30 minute log for the car running at idle.
Thanks.
I did not realize the distributor timing Was Not controlled by the 1227747 computer.
Maybe another Nice vs. Necessary choice? Is it necessary for the TBI to have computer controlled timing, no it's not necessary. Would it be nice to have the Jeep engine running with 1227747 computer controlling the timing, maybe so.
If the budget is available for a VSS and Computer Controlled Timing / Distributor, I think it would be money well spent. Save some budget for a custom chip too.
dave w
In talking to AFI (the system is an early version from 2006), and uses what they called a hybrid setup: an AMC distributor 'stalk', with a GM cap/ignition control module, and separate coil. Am looking at getting a new harness to replace the hacked up one that came in the Jeep, but wanted to get it running well before changing too many things at once.
Went out day before yesterday, and traced grounds, and found i don't have one between the block & frame. Given the Frankenstein nature of this Jeep, am not surprised. Have ordered a new set of battery cables & ground strap to replace the mess i have now & go from there.
Finally had a chance to take a 30-minute test drive & pull a data log. Running-wise: engine died when first put into gear, hesitated when accelerating away from house, and back-firing at speed on the Interstate, when rolling at 70, let off, coast to 60 & get back in it.
For interest, i plotted scatter charts for the main sensors, as well as, uploaded the latest data log they go with - CLOSED loop occurs at data point 214. Would appreciate advice on which direction to proceed.
IAC:
Battery Voltage - ranges from 13.7-14.1
O2 Sensor:
Block Learn Multiplier:
Integrator:
TPS:
MAF:
If I'm reading the BLM plot correctly, the average BLM is Lean (above 128). The other plots look mostly normal.
I'm currently working on a International Harvester (IH) TBI conversion using an EFI Distributor from Performance Distributors ( https://performancedistributors.com/.../distributors/ ). The IH will have computer controlled timing. The IH is using the second generation TBI Computer 16197427. The 1227747 is a good TBI computer, the 16197427 is better because has a faster processor, more tuning parameters, and very affordable.
I built custom EFI Harness, send me a Private Message (PM) if you would like me quote a harness.
dave w
Hey, DaveW - on BLM, agree you're reading it right - average BLM for the entire log period is 135.83. Before we look at ditching what i have, thinking out loud,
Given the age of the system, and the fact that i don't know what the .bin has defined. Have been wondering about what it takes to read the chip to understand what's programmed vs. assuming/guessing? i know AFI originally built the system, but i don't know where the chip came from, and whether it's original, or not. Truth be known, now that i think of it - i really don't know if the two actually went together, or just happened to be sold together... I'm not really interested in burning chips myself, but would love to know how things are supposed to be set, based on the programming. To date, i've read just enough to wonder, but i don't want to spend $100's either on curiosity right now. I feel like we're close to a solution, but can't tell how close.
Also, i've thought about taking it to a shop & having a full vacuum test run (intake & exhaust), and see about putting the leak question to bed. Given the conversations around running 'lean', it seems it's a question of not enough fuel, or too much air.
Right now, i have new battery & ground cables on order - am planning on waiting to see what we get w/that & go from there.
The Moates.net Burn 2 can read the 1227747 chip. https://www.moates.net/burn2-chip-programmer-p-197.html
The 1227747 uses a 2732 chip. The 2732 has variants, 25V, 21V and 12.5V. The 2732 used in the 1227747 is an EPROM which can be erased with a UV light and then reprogrammed. The Moates.net Burn 2 Can Not program a 2732 chip. The Moates.net Burn 2 is READ ONLY for a 2732 chip.
If you want to know what is programmed in your chip, likely the best option is to find someone local to you with a 2732 chip reader.
dave w
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