It's done electronically. The only moving part in the distributor is the shaft/rotor. The signal to fire the spark gets delayed by the ECM/EST circuitry. The longer it delays, the more the spark timing is retarded.
CK5
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TPI = Mass Frusteration!
- Thread starter Russell
- Start date
According to your log your getting the distributor reference signal, it's reflecting the RPM's, which should be 1000 with the resistor between A/B. (and it is at certain points)
Also looks like you are using the wrong settings in winALDL, as you are showing MAP and not MAF. I believe it defaults to the 1227747 ECM, you need to change that to the 1227165 ECM if you are using the '87-89 MAF. Won't fix your problem, but will give more useable info.
PM me with an email address that will accept a large file and you can have the entire troubleshooting section out of the Camaro Service Manual.
Also looks like you are using the wrong settings in winALDL, as you are showing MAP and not MAF. I believe it defaults to the 1227747 ECM, you need to change that to the 1227165 ECM if you are using the '87-89 MAF. Won't fix your problem, but will give more useable info.
PM me with an email address that will accept a large file and you can have the entire troubleshooting section out of the Camaro Service Manual.
That'd be excellent! I do have it set for a `165, and it does show me MAF readings in the digital dash. If I remember correctly, it was usually about 13 gallons per second at about 1000 rpm.
Try sending it to ZieglerDigital @ hotmail.com, if not, I'll find someone to give me a gmail invite, so you can send it to that address instead.
Try sending it to ZieglerDigital @ hotmail.com, if not, I'll find someone to give me a gmail invite, so you can send it to that address instead.
HarryH3 said:
Interesting. When I had that cap off the dizzy, I seem to recall there was some sort of a linkage rod in there. I'll take my cap off tommorow and snap a picture of it.
I know that my TBI small cap HEI has only the module, and rotor under the cap, but I think the big cap HEI was different.
sled_dog
1 ton status
if its a big cap HEI it is most likely not the right one. TPI uses the same small cap setup as TBI.
I know that it is the correct dizzy, they came on the 85 and 86 cars. When they switched over to the center bolt heads in 87, they also switched over to the small cap HEI.
However, I am fairly confident my issue is timing. I'm gonna do some more datalogging using a different program than I was before, which will give me more specific information about my pulsewidth, knock retard, spark advance etc so I can better diagnose my issue.
However, I am fairly confident my issue is timing. I'm gonna do some more datalogging using a different program than I was before, which will give me more specific information about my pulsewidth, knock retard, spark advance etc so I can better diagnose my issue.
Ok, I took the whole dizzy out, turned the engine to TDC, make sure of it using a little hose hooked up to the spark plug hole. Then put the dizzy back in, put the cap back on, with number 1 aligned directly overtop of the rotor tip, then installed the wires, checked the firing order like 6 times, and went to fire it up. The truck will NOT fire at this timing. To make it fire, and have some semblance of running by itself, my timing light shows I have to be at over 50 degrees advance!
I'm beggining to wonder if I messed up my cam install or something else more major!
I'm beggining to wonder if I messed up my cam install or something else more major!
Sounds like you are 180 out now. Easy mistake to make unless you watch the valves or really pay attention to pressure indicating you are coming up on compression. Flip the distributor exactly 180 and try again, I'll bet it fires and runs as well as it did (assuming that the original problem remains).
Alright, I headed out, and did a diagnosis on the engine's ignition system, here are the results:
1. Pulled the plugs, and visually inspected them:
Piston 1 = Clean, but gas fouled
Piston 8 = Dry soot, with clean threads
Piston 4 = Dry soot, with clean threads
Piston 3 = Dry soot, with gas soaked threads. Found this plug loose, was able to back it out by hand
Piston 6 = Dry soot, with clean threads
Piston 5 = Dry soot, gas soaked threads, and ceramic. Found this plug was totally loose, only took about 2 turns to back it out.
Piston 2 = Clean, but gas fouled
All plugs are AC Delco, and are the correct lenth, and heat for my heads. All were, and still are gapped at .045
2. Did a dry compression test on the engine. All plugs removed, compression tester installed in cylinder to be tested. I allowed the starter to turn so each cylinder had 6 compression strokes, just counted when the starter worked hard to turn the engine over.
Piston 1 = 140 PSI
Piston 8 = 148 PSI
Piston 4 = 140 PSI
Piston 3 = 140 PSI
Piston 6 = 140 PSI
Piston 5 = 140 PSI
Piston 7 = 150 PSI
Piston 2 = 140 PSI
3. Checked the continuity, and resistance of all the plug wires, along with a visual inspection for cuts, burns or other damage.
Piston 1 = 12.93K Ohms
Piston 8 = 7.10K Ohms
Piston 4 = 9.85K Ohms - Found a burn on the plug side boot, possible loss of spark under load to the header
Piston 3 = 10.63K Ohms
Piston 6 = 7.21K Ohms
Piston 5 = 9.63K Ohms
Piston 7 = 7.95K Ohms
Piston 2 = 14.38K Ohms - Found a cut in the plug side boot, possible loss of spark under load to the header
4. Removed dizzy, and driver's side valve cover. Turned the crank by hand until I felt air being pushed out of the plug hole, and saw that both valves were shut. Brought the timing tab up to 0 degrees, right where a guy can feel that the piston is at TDC with a screwdriver. Timing tab is accurate, immedately after passing the 0 degree mark, the piston begins to go back down into the bore. Re-set the tab to 0 again, re-installed driver's side valve cover, and set the dizzy back in, re-installing the cap, and re-connected all the electrical, less the plug wires.
5. Re-routed all plug wires to avoid running any of them within 3 inches of any sensor wiring. Several plug wires ran parallel to the sensory harness, one actually resting on the looming.
6. Removed, cleaned, and re-installed all grounds in the truck. This includes the grounding terminal block on the emergency brake assembly, the emergency brake assembly to cab connection, cab to engine connection, engine to frame connection, and battery to engine connection.
7. Tried running the truck, with no noticeable improvement. If I turn the dizzy so the truck will somewhat attempt to idle on its own, and check the timing, I have to turn the advance dial on my timing light to approx 50 degrees before the timing tab appears to return to 0.
The compression numbers seem remotely low, but this engine averaged about 125 - 130 before I removed the engine, replaced all the gaskets and installed the TPI. It ran like a top before that with the 125 - 130 compression, very smooth, plenty of power. The engine broke in on the old q-jet, and typical HEI somewhat properly. The engine did backfire out of the passenger's side header, as it primarily does now during break-in, but I had chalked that one up to two dead cylinders on the pass side due to a rather large crack in the dizzy cap (you could see it arching out and down to the dizzy base when the engine was idling)
The Check engine light acts as it should on when you have the truck in the on position, off once you get it to run, until a flag is set. If you jumper the ALDL, the ECM displays the aldl jumpered code, then the MAF high code, then the rich code.
The ECM is adjusting the timing, I got it so if I ran to the front of the truck fast enough, I could catch it before it died, and keep it going with my hand on the throttle body. When I increase the throttle, the timing mark dissapears, so I do believe the that it is attempting to set the timing.
The ECM tells me that it is running about 12 degrees at an "idle" bumping up to nearly 36 degrees when I attempt to rev it.
1. Pulled the plugs, and visually inspected them:
Piston 1 = Clean, but gas fouled
Piston 8 = Dry soot, with clean threads
Piston 4 = Dry soot, with clean threads
Piston 3 = Dry soot, with gas soaked threads. Found this plug loose, was able to back it out by hand
Piston 6 = Dry soot, with clean threads
Piston 5 = Dry soot, gas soaked threads, and ceramic. Found this plug was totally loose, only took about 2 turns to back it out.
Piston 2 = Clean, but gas fouled
All plugs are AC Delco, and are the correct lenth, and heat for my heads. All were, and still are gapped at .045
2. Did a dry compression test on the engine. All plugs removed, compression tester installed in cylinder to be tested. I allowed the starter to turn so each cylinder had 6 compression strokes, just counted when the starter worked hard to turn the engine over.
Piston 1 = 140 PSI
Piston 8 = 148 PSI
Piston 4 = 140 PSI
Piston 3 = 140 PSI
Piston 6 = 140 PSI
Piston 5 = 140 PSI
Piston 7 = 150 PSI
Piston 2 = 140 PSI
3. Checked the continuity, and resistance of all the plug wires, along with a visual inspection for cuts, burns or other damage.
Piston 1 = 12.93K Ohms
Piston 8 = 7.10K Ohms
Piston 4 = 9.85K Ohms - Found a burn on the plug side boot, possible loss of spark under load to the header
Piston 3 = 10.63K Ohms
Piston 6 = 7.21K Ohms
Piston 5 = 9.63K Ohms
Piston 7 = 7.95K Ohms
Piston 2 = 14.38K Ohms - Found a cut in the plug side boot, possible loss of spark under load to the header
4. Removed dizzy, and driver's side valve cover. Turned the crank by hand until I felt air being pushed out of the plug hole, and saw that both valves were shut. Brought the timing tab up to 0 degrees, right where a guy can feel that the piston is at TDC with a screwdriver. Timing tab is accurate, immedately after passing the 0 degree mark, the piston begins to go back down into the bore. Re-set the tab to 0 again, re-installed driver's side valve cover, and set the dizzy back in, re-installing the cap, and re-connected all the electrical, less the plug wires.
5. Re-routed all plug wires to avoid running any of them within 3 inches of any sensor wiring. Several plug wires ran parallel to the sensory harness, one actually resting on the looming.
6. Removed, cleaned, and re-installed all grounds in the truck. This includes the grounding terminal block on the emergency brake assembly, the emergency brake assembly to cab connection, cab to engine connection, engine to frame connection, and battery to engine connection.
7. Tried running the truck, with no noticeable improvement. If I turn the dizzy so the truck will somewhat attempt to idle on its own, and check the timing, I have to turn the advance dial on my timing light to approx 50 degrees before the timing tab appears to return to 0.
The compression numbers seem remotely low, but this engine averaged about 125 - 130 before I removed the engine, replaced all the gaskets and installed the TPI. It ran like a top before that with the 125 - 130 compression, very smooth, plenty of power. The engine broke in on the old q-jet, and typical HEI somewhat properly. The engine did backfire out of the passenger's side header, as it primarily does now during break-in, but I had chalked that one up to two dead cylinders on the pass side due to a rather large crack in the dizzy cap (you could see it arching out and down to the dizzy base when the engine was idling)
The Check engine light acts as it should on when you have the truck in the on position, off once you get it to run, until a flag is set. If you jumper the ALDL, the ECM displays the aldl jumpered code, then the MAF high code, then the rich code.
The ECM is adjusting the timing, I got it so if I ran to the front of the truck fast enough, I could catch it before it died, and keep it going with my hand on the throttle body. When I increase the throttle, the timing mark dissapears, so I do believe the that it is attempting to set the timing.
The ECM tells me that it is running about 12 degrees at an "idle" bumping up to nearly 36 degrees when I attempt to rev it.
So are you still getting the EST code, or are you getting high MAF/rich codes only?
To make sure you are dead on with initial stab of the distributor, set the engine to TDC, hook up timing light to #1 wire, key on, and twist the dist until it fires. That's 0*.
Verify that all of your injectors are pulsing. Wet in some cylinders and not others isn't really possible unless the plugs aren't firing for some reason(s). The only real consistency I see in your plug data is that the odd bank has a bunch of gas fouled plugs, while the even bank for the most part is dry. Being batch fire, you COULD have an entire dead bank of injectors if one of the two injector fuses pops. I know mine will run fairly smooth on 6 cylinders, whats the loss of two more?
Can't even really tell if one cylinder is dead. Something to check, but that doesn't do anything for that timing issue.
To make sure you are dead on with initial stab of the distributor, set the engine to TDC, hook up timing light to #1 wire, key on, and twist the dist until it fires. That's 0*.
Verify that all of your injectors are pulsing. Wet in some cylinders and not others isn't really possible unless the plugs aren't firing for some reason(s). The only real consistency I see in your plug data is that the odd bank has a bunch of gas fouled plugs, while the even bank for the most part is dry. Being batch fire, you COULD have an entire dead bank of injectors if one of the two injector fuses pops. I know mine will run fairly smooth on 6 cylinders, whats the loss of two more?
Can't even really tell if one cylinder is dead. Something to check, but that doesn't do anything for that timing issue.
ya sure your valves are adjusted properly? now that i hear it backfired with the carb too...
most ok small blocks will give ya 125 to 150 with 5 puffs on the gauge depending on freshness and setup..
most ok small blocks will give ya 125 to 150 with 5 puffs on the gauge depending on freshness and setup..
Only getting the rich and MAF code. MAF is only a little bit high, but that code may also be caused by other sensory issues, such as minimum air, and TPS not being set quite right etc. Rich code is probally caused by the high MAF code. as well.
I just ran out and tried the flash trick. I was a bit on the advanced side, but now I know for sure I am on zero. The engine is trying to fire now, but isn't quite making it.
I'm starting to wonder if maybe my issue has something to do with my injectors. I was reading my data sheet on the injectors, and the fella told me that they were starting to cut out between 41 and 45 PSI, right where the TPI needs to be running. I've got good pressure, 43 PSI that only drops to 39 within a minute, but that is typical. They are a Rochester type injector, and the guy at the injection shop tells me that he personally hates the injectors. He says they regularly start to get bad as they get older, and cannot be cleaned like the older Bosch type injectors.
I spotted a nice looking set of Ford 24 lb Bosch injectors that I am going to bid on, and install. Maybe that'll help out a bit.
If my cam timing was way off, then my compession would be terrible. So my compression is reasonably decent now, and the spark is happening close that my engine should be able to start, leaving me to believe that is must be a fuel issue.
I just ran out and tried the flash trick. I was a bit on the advanced side, but now I know for sure I am on zero. The engine is trying to fire now, but isn't quite making it.
I'm starting to wonder if maybe my issue has something to do with my injectors. I was reading my data sheet on the injectors, and the fella told me that they were starting to cut out between 41 and 45 PSI, right where the TPI needs to be running. I've got good pressure, 43 PSI that only drops to 39 within a minute, but that is typical. They are a Rochester type injector, and the guy at the injection shop tells me that he personally hates the injectors. He says they regularly start to get bad as they get older, and cannot be cleaned like the older Bosch type injectors.
I spotted a nice looking set of Ford 24 lb Bosch injectors that I am going to bid on, and install. Maybe that'll help out a bit.
If my cam timing was way off, then my compession would be terrible. So my compression is reasonably decent now, and the spark is happening close that my engine should be able to start, leaving me to believe that is must be a fuel issue.
sled_dog
1 ton status
do you have a driver tester set or injector tester? We have some tools at school I love for testing fuel injectors. One fires the injector for a set number of pulses so you can check the fuel pressure drop in the rail during this test. Diagnosed one or two bad injectors with that already.
That'd be a really handy tool. I just paid 40 bucks for a dude to do that to all my injectiors though, so according to him, they are good at pressures lower than 40 PSI, at which point he said that they began to get irregular spray patterns, or quit firing all together.
I've got a noid light, and all of the injectors are getting noid pulses, but something else must be amiss. Cause yeah, like I said, you need fuel air and spark to have a fire, and I'm certain I've got air and spark, so its gotta be fuel now.
I've got a noid light, and all of the injectors are getting noid pulses, but something else must be amiss. Cause yeah, like I said, you need fuel air and spark to have a fire, and I'm certain I've got air and spark, so its gotta be fuel now.
You read up on the injectors, right? Don't know if the Ford SVO stuff is Bosch or what.
SVO's are about $200 from Summit, so don't get taken in an auction. The SVO's seem to be very good injectors, but reports differ on whether or not yoU NEED to modify the PROM to run them. I never was able to deceipher who was correct...if you read long enough on thirdgen.org you'll see people say that they are rated at a different fuel pressure so the lb/hr numbers aren't the same as GM, but some say that's not entirely true.
I've got a couple of injectors that aren't in the same range on my motor, and I'll eventually go with the SVO's.
By the way, on the MAF issue, are you getting "reasonable" readings that change when you are scanning? IIRC the '85 uses a crummy MAF setup, and I *think*, but am not sure, that MAF isn't the same as '86-89, so if you've got an '85, and the MAF has been replaced (or a newer ECM with old MAF) and your readings aren't right, you could have some issues there.
I was playing around with no air cleaner on mine, but put pantyhose over the inlet of the MAF just to keep major stuff out, and what I thought was a little restriction made a HUGE difference in how the engine ran.
SVO's are about $200 from Summit, so don't get taken in an auction. The SVO's seem to be very good injectors, but reports differ on whether or not yoU NEED to modify the PROM to run them. I never was able to deceipher who was correct...if you read long enough on thirdgen.org you'll see people say that they are rated at a different fuel pressure so the lb/hr numbers aren't the same as GM, but some say that's not entirely true.
I've got a couple of injectors that aren't in the same range on my motor, and I'll eventually go with the SVO's.
By the way, on the MAF issue, are you getting "reasonable" readings that change when you are scanning? IIRC the '85 uses a crummy MAF setup, and I *think*, but am not sure, that MAF isn't the same as '86-89, so if you've got an '85, and the MAF has been replaced (or a newer ECM with old MAF) and your readings aren't right, you could have some issues there.
I was playing around with no air cleaner on mine, but put pantyhose over the inlet of the MAF just to keep major stuff out, and what I thought was a little restriction made a HUGE difference in how the engine ran.
I've been looking into the injectors, and I'm just gonna get myself a set of rochester 350 injectors from a 350. These multec injectors appear to be junk according to what most people have to say about them.
The MAF is from an 86 setup, just like my ECM is. I did infact start with an 85 setup, but upgraded before I did anything.
The harness is custom made to fit my truck, and since I made it, and I checked every single circuit more times than you can count, I am fairly confident that it is working correctly.
Basically, I know that my spark is going into the cylinder at the correct time, so the only other thing it could possibly be is fuel. To test that theory, I plan to release some propane into the MAF sensor, unplug the injectors, and see if the engine will start and run on it. If thats the case, then I can be sure that my problem lies in the injectors.
The MAF is from an 86 setup, just like my ECM is. I did infact start with an 85 setup, but upgraded before I did anything.
The harness is custom made to fit my truck, and since I made it, and I checked every single circuit more times than you can count, I am fairly confident that it is working correctly.
Basically, I know that my spark is going into the cylinder at the correct time, so the only other thing it could possibly be is fuel. To test that theory, I plan to release some propane into the MAF sensor, unplug the injectors, and see if the engine will start and run on it. If thats the case, then I can be sure that my problem lies in the injectors.
Have you checked resistance on the injectors? Real easy to do with a multimeter, you just measure across the injector pins. They should all fall within a similar range, but if you had them flowmatched or whatever, I'd expect that they would pass the ohm test. It's just a basic test, but easy.
They are all exactly 17 ohms.
I just tried the propane trick, I pulled the brake booster line, put my propane torch in the end, and put about 10 PSI of propane into that line. Cranked the engine, and while it sputtered a heck of a lot more, it still wouldn't take. So thats gotta be plenty of fuel, returning us back to it being a dizzy problem now.
I think I am gonna take one of my old HEI dizzies, and drop it in there, and give that a shot with the propane. That'd let me know if it is a problem with the dizzy, or if it is a problem with plug wires etc.
I just tried the propane trick, I pulled the brake booster line, put my propane torch in the end, and put about 10 PSI of propane into that line. Cranked the engine, and while it sputtered a heck of a lot more, it still wouldn't take. So thats gotta be plenty of fuel, returning us back to it being a dizzy problem now.
I think I am gonna take one of my old HEI dizzies, and drop it in there, and give that a shot with the propane. That'd let me know if it is a problem with the dizzy, or if it is a problem with plug wires etc.
Hossbaby50
3/4 ton status
swap your plug wires 180* around the cap and give it a shot. When I did my TPI swap I had the dist. 180* out and it would backfire threw the throttle body. It would try and fire but wouldn't. I moved the spark plug wires 4 positions around the cap and bang. It fired right up.
Harley
Harley
Just went and put my old non-efi HEI in, put my propane torch through the throttle body, and turned the key. It fired and would run for a few seconds on it, then use all the propane up in the intake, and die. If a guy was able to deliver more propane, or lessen the amount of air, I'd run that way.
This only goes to confirm my theory that it is something wrong with the TPI, not with my engine.
Thats one thing down, next up is to knock my fuel system off the list, then its on to timing, once I know for sure that is fine, its finally off to figure out what went wrong with the wiring, though I am very confident the wiring is fine.
BTW -- when I set the engine to TDC (turned it twice to make sure it was on the compression stroke) I had my dizzy in the right way, so that for sure isn't the problem. It'd run somewhat before anyways, just not well at all.
This only goes to confirm my theory that it is something wrong with the TPI, not with my engine.
Thats one thing down, next up is to knock my fuel system off the list, then its on to timing, once I know for sure that is fine, its finally off to figure out what went wrong with the wiring, though I am very confident the wiring is fine.
BTW -- when I set the engine to TDC (turned it twice to make sure it was on the compression stroke) I had my dizzy in the right way, so that for sure isn't the problem. It'd run somewhat before anyways, just not well at all.
