Purchase a set of ngk 3332. Personally I'm not a fan of autolite. Ac is a good plug as well. Also I would suggest running the msd 8226 coil as it is the proper coil to use with GM systems.
MPFI Questions
- Thread starter Heckelbone
- Start date
Heckelbone
New member
Status:
new ngk plugs
new flamethrower coil
Have not replaced the thermostat, couldn't find one locally.
Decreased injector flow rate to 18.5 from 18.99.
Started it, ran nicely. Let it warm up. O2 sensor was 430mv, blm steady 128.
Stopped and restarted it a few times. Then, once it stumbled upon starting, flooded and couldn't be restarted.
When I turn on the power without starting it, the injectors chatter noticeably.
I let it sit a few hours and tried again.
Started up, ran nicely. Stopped, restarted, didn't catch the first time and flooded. Smells and sounds like a lot of gas is being poured in the manifold when I first turn on the system.
I took one of the 'fouled' plugs and attached a dizzy wire to it while grounding the body and turning the engine over, and it sparks nicely. So I'm dubious about being fouled, or the new coil cuts through the soot.
new ngk plugs
new flamethrower coil
Have not replaced the thermostat, couldn't find one locally.
Decreased injector flow rate to 18.5 from 18.99.
Started it, ran nicely. Let it warm up. O2 sensor was 430mv, blm steady 128.
Stopped and restarted it a few times. Then, once it stumbled upon starting, flooded and couldn't be restarted.
When I turn on the power without starting it, the injectors chatter noticeably.
I let it sit a few hours and tried again.
Started up, ran nicely. Stopped, restarted, didn't catch the first time and flooded. Smells and sounds like a lot of gas is being poured in the manifold when I first turn on the system.
I took one of the 'fouled' plugs and attached a dizzy wire to it while grounding the body and turning the engine over, and it sparks nicely. So I'm dubious about being fouled, or the new coil cuts through the soot.
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Heckelbone
New member
Update
I found that part of my issue was the distributor cap and rotor were fried.
I replaced them and the wire to my coil. Then it started right up.
I will collect some data and send it on shortly.
I have noticed that if the engine doesn't catch on the first or second try, it seems to flood and cannot be started until it dries out.
Does this type of symptom make sense, or does it point to a different issue, like a vacuum leak?
Thanks.
I found that part of my issue was the distributor cap and rotor were fried.
I replaced them and the wire to my coil. Then it started right up.
I will collect some data and send it on shortly.
I have noticed that if the engine doesn't catch on the first or second try, it seems to flood and cannot be started until it dries out.
Does this type of symptom make sense, or does it point to a different issue, like a vacuum leak?
Thanks.
ldo_marlin
Member
Since you have tunerpro, you can see the data as the engine is running and dying. There is alot of data there that you can use to analyze the problem
how many miles on the the old cap and rotor that was fried? Have you always had this foul plug issue? What do the terminals of new cap and rotor look like now? Your dizzy looks to be one of the early hybrid dizzy (IH bottom, Chevy top)? The flamethrower coil will work for GM est application? My guess at this point is you still have some ignition issues. Some of the earlier hybrid dizzy were not machined correctly
how many miles on the the old cap and rotor that was fried? Have you always had this foul plug issue? What do the terminals of new cap and rotor look like now? Your dizzy looks to be one of the early hybrid dizzy (IH bottom, Chevy top)? The flamethrower coil will work for GM est application? My guess at this point is you still have some ignition issues. Some of the earlier hybrid dizzy were not machined correctly
Heckelbone
New member
I'll log some data and get it up as soon as I can.
I had less than 1,000 miles on the last cap and rotor.
No, I've not always had it, but then again I've never really had it running correctly since I started this mpfi journey. The only thing I changed about that time was a 35 gal gas tank with an in-tank pump. Fuel pressure is the same, 40psi.
My local mechanic was raving about the flame-thrower coil and it's higher potential cutting through more gunk.
The cap and rotor are a little less than shinny new after about 20 minutes, but now I can't get it running again.
I am unsure of the distributor... It was part of the afi kit, but it does have a IH base and what looks like a GM top.
If I take a plug out now, it is black, but I can ground the body and get a nice spark when I turn the engine over.
I can carefully cut the old cap and measure clearances if that might help debug.
I had less than 1,000 miles on the last cap and rotor.
No, I've not always had it, but then again I've never really had it running correctly since I started this mpfi journey. The only thing I changed about that time was a 35 gal gas tank with an in-tank pump. Fuel pressure is the same, 40psi.
My local mechanic was raving about the flame-thrower coil and it's higher potential cutting through more gunk.
The cap and rotor are a little less than shinny new after about 20 minutes, but now I can't get it running again.
I am unsure of the distributor... It was part of the afi kit, but it does have a IH base and what looks like a GM top.
If I take a plug out now, it is black, but I can ground the body and get a nice spark when I turn the engine over.
I can carefully cut the old cap and measure clearances if that might help debug.
ldo_marlin
Member
Cap & rotor on TBI/tpi systems should last much much longer than 1000 miles. In fact, I've seen TBI/tpi cars/trucks running 50k+ miles on the same plugs, cap, rotor. Something is not right with your spark system. Can you take a close up picture of the inside terminals of the old cap+rotor and the new set. I am wondering if your dizzy wobbles when it spins. Is the shaft in the dizzy loose ?
The other possibility is your est is intermittently failing. A wrong coil can kill the est. There is really no need to upgrade the TBI/tpi coil. The used spark plugs in these systems are usually light tan colored. They make plenty of spark.
One more thing, how is the engine grounded? Engine block to battery?
The other possibility is your est is intermittently failing. A wrong coil can kill the est. There is really no need to upgrade the TBI/tpi coil. The used spark plugs in these systems are usually light tan colored. They make plenty of spark.
One more thing, how is the engine grounded? Engine block to battery?
Heckelbone
New member
The distributor shaft is tight and has no wobble.
The system is grounded to a single point on the intake manifold, then on the other side of the manifold I have it grounded to the chassis with a 8ga cable.
I have attached pictures of the new and the old distributor caps.
I will get a new ecs module for the distributor and see if that changes anything.
Thanks for your suggestions and patience while I work through this!
The system is grounded to a single point on the intake manifold, then on the other side of the manifold I have it grounded to the chassis with a 8ga cable.
I have attached pictures of the new and the old distributor caps.
I will get a new ecs module for the distributor and see if that changes anything.
Thanks for your suggestions and patience while I work through this!
Attachments
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ldo_marlin
Member
The old dizzy cap does not look that bad. If all contact terminals look about the same and the rotor tip & center button are not worn down, I doubt the problem was the dizzy cap and rotor. The 2 contact points at the terminals look correct so your dizzy shaft is ok (check all 8 contact points to be sure).
Besides the 8 ga ground cable from engine to frame, are there any other ground cable from engine to frame or battery? If not, you should add a larger ga ground cable. What ga ground cable from battery (-) to frame?
Besides the 8 ga ground cable from engine to frame, are there any other ground cable from engine to frame or battery? If not, you should add a larger ga ground cable. What ga ground cable from battery (-) to frame?
Heckelbone
New member
(edit) there is an 8ga cable from the neg battery terminal to one of the mounting bolts for the pwr steering pump into the port head.
I took apart my ground cables, cleaned & re d/e greased.
Took out the plugs and cleaned them.
Tried another distributor ignition switch unit.
I had tunerpro ready to go to record it starting up. I could not connect to the ecu.
The engine ran roughly for <30 sec.
With the power on, but not running, the injectors chatter.
I put a video of them up on youtube:
youtube - injectorchatter
Usually does it more than what is in the video, but that is just one take.
Thoughts?
I took apart my ground cables, cleaned & re d/e greased.
Took out the plugs and cleaned them.
Tried another distributor ignition switch unit.
I had tunerpro ready to go to record it starting up. I could not connect to the ecu.
The engine ran roughly for <30 sec.
With the power on, but not running, the injectors chatter.
I put a video of them up on youtube:
youtube - injectorchatter
Usually does it more than what is in the video, but that is just one take.
Thoughts?
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Bill USN-1
F.I. Moderator
I would be checking all the ignition module connections and maybe look at routing them differently.
May want to verify the ground on the distr and ignition module.
May want to verify the ground on the distr and ignition module.
ldo_marlin
Member
X2 .
Check for correct connections and ground. Probably be best to do a voltage check at all ecu pins with key on . You can find a voltage reference list on the web.
You mentioned below that engine ran for 30secs. Did it die after that ? From flooding?
The injectors should not be chattering when key on and engine not running. Could be from bad ground. Or May be the ecu thinks the egine is running with key on (wrong connection).
Also good ground is your friend. Put a 4 gauge ground cable from batt to power steering mount. Or at least add another 8 gauge ground cable. 8 gauge is too small to carry enough current for starting.
Bill USN-1
F.I. Moderator
The ECM needs to recieve the distr ref pulse before it fires the injectors.
So I would lean towards the ignition wiring and electical interference.
Or the ECM is really bad.
So I would lean towards the ignition wiring and electical interference.
Or the ECM is really bad.
Heckelbone
New member
All,
after diagnosing down to the dizzy, afi set me up with a newly rebuilt distributor with a remote mounted ignition module.
While I was at it I rebuilt the fuel plumbing and added a fuel pressure regulator with a gauge on it. These are shown in the attached pictures.
Now when I turn it over, it fires up on all cylinders and then promptly dies.
It'll run for about two seconds, but it does fire up, which it did not do before, so I think we were right about the distributor.
I set the timing to 0 tdc and can move it around between 0-10deg and see it with a timing light while it runs.
Now I will dink around and try to keep it running, but things are looking up.
after diagnosing down to the dizzy, afi set me up with a newly rebuilt distributor with a remote mounted ignition module.
While I was at it I rebuilt the fuel plumbing and added a fuel pressure regulator with a gauge on it. These are shown in the attached pictures.
Now when I turn it over, it fires up on all cylinders and then promptly dies.
It'll run for about two seconds, but it does fire up, which it did not do before, so I think we were right about the distributor.
I set the timing to 0 tdc and can move it around between 0-10deg and see it with a timing light while it runs.
Now I will dink around and try to keep it running, but things are looking up.
Attachments
Heckelbone
New member
Update
Hi gents,
I'm still not running right. Norm at afi checked my two ecus, and they both work fine. I can connect to my moates emulator, download and upload.
I put each ecu in the Scout and have the same issues, and I cannot get aldl data, the check engine light is on solid, and black smoke out the back.
I tried the following and the check engine light went off.
Any thoughts?
No aldl data, won't flash code 12, light on steady: this is usually caused by a shorted (brn/wht) wire to ground, or a open wire in the aldl terminal "a" to ECM pin a9, when the terminals "a" and "b" are connected for a diagnostic check. First try unplugging the a-b ECM connector, if the light goes off, then the brn/wht wire is not shorted to ground, and the wht/blk wire from the aldl to ECM is not opened. Check all terminal connectors. If they check out, the problem is a faulty memcal, or ECM. If a code did not flash, the ECM should be replace using the original memcal. Replace the memcal only if a ECM swap did not correct the problem.
Hi gents,
I'm still not running right. Norm at afi checked my two ecus, and they both work fine. I can connect to my moates emulator, download and upload.
I put each ecu in the Scout and have the same issues, and I cannot get aldl data, the check engine light is on solid, and black smoke out the back.
I tried the following and the check engine light went off.
Any thoughts?
No aldl data, won't flash code 12, light on steady: this is usually caused by a shorted (brn/wht) wire to ground, or a open wire in the aldl terminal "a" to ECM pin a9, when the terminals "a" and "b" are connected for a diagnostic check. First try unplugging the a-b ECM connector, if the light goes off, then the brn/wht wire is not shorted to ground, and the wht/blk wire from the aldl to ECM is not opened. Check all terminal connectors. If they check out, the problem is a faulty memcal, or ECM. If a code did not flash, the ECM should be replace using the original memcal. Replace the memcal only if a ECM swap did not correct the problem.
ldo_marlin
Member
1) norm checks your ecu and says it's fine
2) you plug the same working ecu in your truck and check engine light goes on
3) you can't connect aldl
if the ecu is good, the difference looks to be the set up on your truck vs. Norms' set up. I'd look over the whole FI wiring and do a voltage check at all ecu pins. Lots of info on thirdgen.org. It's pia but that's what I'd do.
2) you plug the same working ecu in your truck and check engine light goes on
3) you can't connect aldl
if the ecu is good, the difference looks to be the set up on your truck vs. Norms' set up. I'd look over the whole FI wiring and do a voltage check at all ecu pins. Lots of info on thirdgen.org. It's pia but that's what I'd do.
Heckelbone
New member
I know, I know....it's just so much time to go through it all bit by bloody bit.
Basically I have to verify continuity in each end-connector through to the inside the pins inside the ecu. Then, if I don't find anything, check each thing that plugs into it.
Basically I have to verify continuity in each end-connector through to the inside the pins inside the ecu. Then, if I don't find anything, check each thing that plugs into it.
- how quick could you hack through this?
- should I put this thing back together with velcro?
Kurt Kiefer
New member
It has been a year and a half since your last post. Did you ever find the problem and get it running right?