If I had any hair left, I'd tear it out

[AJ77]

Ever since I got my engine put back together with the new cam, I haven't been able to get it to run right. It won't idle right about two thirds of the time. I pull up to a stop sign and if I don't play with the gas pedal for about 5 seconds it will die. After that it will idle all day. Sometimes all I have to do is put it in gear from park and it will die. At cruise speed it will just start bucking like the power wire to the computer is being disconnected for about 1/2 second at a time. It bucks so hard I'm afraid it is going to break something in the drivetrain. At medium acceleration, it runs great most of the time but if I put my foot to the floor it vibrates so bad I can't even see out of the mirrors and at about 4500 RPM the check engine light comes on. When I pull the codes it says low and high voltage at the TPS at the same time? I'm thinking the vibration is coming from misfiring. I've changed the TPS, the computer, the dist. cap, rotor and plugs. I ohmed out the plug wires and they're ok. I've got the TPS set @ .52 V at idle and the potentiometer is working. When I changed the cap this last time, the contacts inside were totally covered with what looked like soot from a tailpipe?? Could a coil taking a shit cause all this? I have a new fuel pump, both filters, had the injectors cleaned and flowtested. Fuel pressure is set at 45 PSI. I have spark at all plugs however it seems weak. I have to get the end of the wire right up against the header before I can see a spark and then it just doesn't seem like it's very stong. :cussing: Sometimes I can drive for an hour or more with no problem, but I can park the car long enough to fill the tank and when I restart it it's missing so bad I'm not sure I'm going to make it home. I'll get a mile or two down the road and it will just kind of pop and all is well again for a while.I've got a new coil on the way from Jegs but it won't be here till Tuesday. Sorry for the long post, but I'm at my wit's end.

 

[big2bird]

Ever since I got my engine put back together with the new cam, I haven't been able to get it to run right. It won't idle right about two thirds of the time. I pull up to a stop sign and if I don't play with the gas pedal for about 5 seconds it will die. After that it will idle all day. Sometimes all I have to do is put it in gear from park and it will die. At cruise speed it will just start bucking like the power wire to the computer is being disconnected for about 1/2 second at a time. It bucks so hard I'm afraid it is going to break something in the drivetrain. At medium acceleration, it runs great most of the time but if I put my foot to the floor it vibrates so bad I can't even see out of the mirrors and at about 4500 RPM the check engine light comes on. When I pull the codes it says low and high voltage at the TPS at the same time? I'm thinking the vibration is coming from misfiring. I've changed the TPS, the computer, the dist. cap, rotor and plugs. I ohmed out the plug wires and they're ok. I've got the TPS set @ .52 V at idle and the potentiometer is working. When I changed the cap this last time, the contacts inside were totally covered with what looked like soot from a tailpipe?? Could a coil taking a shit cause all this? I have a new fuel pump, both filters, had the injectors cleaned and flowtested. Fuel pressure is set at 45 PSI. I have spark at all plugs however it seems weak. I have to get the end of the wire right up against the header before I can see a spark and then it just doesn't seem like it's very stong. :cussing: Sometimes I can drive for an hour or more with no problem, but I can park the car long enough to fill the tank and when I restart it it's missing so bad I'm not sure I'm going to make it home. I'll get a mile or two down the road and it will just kind of pop and all is well again for a while.I've got a new coil on the way from Jegs but it won't be here till Tuesday. Sorry for the long post, but I'm at my wit's end.

You should have a 1/2" long fat blue spark when the ignition is working properly. Tell us more. Since 77 didn't have EMS and injection, you obviously are custom. What kind of system and ignition?

 

[AJ77]

It's a 383 stroker with an aftermarket (First Fuel Injection) TPI system. It has an OBD-1 computer, distributor and all sensors the same as a 90 Camaro. Custom chip burned for my engine specs. It is a MAP system. It seems to me like the spark should be hotter also. Why the contacts in the cap are all sooted up escapes me though? It is all powdery black like the inside of a tailpipe on a car that's running a little rich.

I forgot to add that right now I have an MSD Blaster 2 coil. It's the round, oil filled type. The one I have on order is also an MSD, but it is the Jegs # 121-8207 square type. I ordered that one on recommendation from the place that manuf. the injection system.

 

[big2bird]

Let's start with the ignition. If it's jacked up, the rest will drive you bonkers. I don't know what's in a 90 Camaro. Is it a comp controlled HEI ? A 4 pin/7 pin?

 

[mrvette]

Let's start with the ignition. If it's jacked up, the rest will drive you bonkers. I don't know what's in a 90 Camaro. Is it a comp controlled HEI ? A 4 pin/7 pin?

It is a 7 pin on the HEI module, and his problem is most likely water in the fuel....

remember my threads about the problem?? drove me Krazy for some years?? on and off again....

first it has to be proven it's nothing in the ignition, but I actually had TWO PROVABLE PROBLEMS running concurrently.....so the thing was to get Jacobs ceramic boots on especially 4&6 plugs on MY headers to stop the boot breakdown....arcing to the header at the damndest intermittant times when IT wanted to, and it had NOTHING TO DO WITH moisture or weather or me soaking windex on it. or anything I could find....UNTILL the damn thing snapped at me when I was about literally banding my head on the driver's fender on a summer day of sunshine, and that dirty rotton son of a BITCH did a spark to the header, right under my nose.....the Jacobs ceramics cured THAT shit in a hurrry.....so gone was the really worst of the idle problems....

the rest of it SOUNDS like where you are....WATER IN THE FREEKING TANK....drain the tank and then pull out the sludge off the bottom of the tank and dry it out with a towel on a poker....refill with fresh gas, and turn on the pump....since doing that almost 2 months ago with MY '72 the thing runs about perfect....it's a totally insidious son of a bitch as sometimes like yours it would run just fine...under acceleration it would SEEM fine....
but the idle would mostly absolutely suck, not all the time and very inconsistant in happening....some daze just fine....more often raggedy assed, sometimes it pissed me off to the point of a sledgehammer for computer tuning.....

and I have tosses wrenches throug steel fenders before.....:smash:

 

[big2bird]

Gene,
He said he almost has to "touch" the headers to get a spark. That's just not right.

 

[mrvette]

Gene,
He said he almost has to "touch" the headers to get a spark. That's just not right.

Yeh, I looked at that too, but then thought if the boots were on there, it would act like that...bare metal, surely U B correct....

Riotous tale about a old 'friend' who knocked his ass back into the weeds pretty good TWICE with a plug wire pull....

:rofl::rofl::rofl: took Larry and me a hour to get off the deck laughing....

 

[AJ77]

Yea Gene's right, it's a 7 pin. There are two sockets on the ignition module. One has two pins, the other has four. Then there's another external wire for the electronic advance. I've already got ceramic spark plug extenders from Wrench Rat. They put the plug boot about 3" away from the header pipe. It also is not water in the fuel. It's the same fuel that was in the tank before I pulled the motor. Not two months ago I pulled the tank and removed the bladder, completely cleaned the inside,(there wasn't anyting in there anyway) and reinstalled it. I know what water in the fuel does and this isn't it. Water in the fuel isn't going to cause carbon buildup on the distributor cap contacts. It's definitely electrical, I just don't know what yet. I buy fuel from the same station my wife does for her Infiniti and she has no problem? It's running so poorly that it almost doesn't make a difference in the way it idles when I pull a plug wire. I changed the plugs the other day and the ones I took out still looked almost new. Very little sign of firing at all. The ground lug was still almost shiny looking. If the new coil coming in Tuesday doesn't fix it, I might be forced to rip out the entire engine management system and buy the new one from Accel. It has a crank trigger/cam position sensor distributor and the computer is like a brand new car. It can be run in sequential mode and has full diagnostics and is fully laptop programmable. Jegs has it for about $1800.00. It comes with a wide band O2 sensor and it can be set up to control fuel at each cylinder individually. What kills me is that it was running perfectly till I wiped the cam and pulled the engine. Wierd??

 

[big2bird]

Stock GM HEI coil in cap coils rarely go out.
It sounds more like the module has crapped out. Cheap and easy to change.
Do you have a VOM? You can test the coil.
It looks like this one,correct?

 

[mrvette]

Stock GM HEI coil in cap coils rarely go out.
It sounds more like the module has crapped out. Cheap and easy to change.
Do you have a VOM? You can test the coil.
It looks like this one,correct?
[

I have found ONE HEI coil with funky crimp contacts as they crimp ALL the coil wires with the tabs and do NOT CLEAN the formvar off the wires first...I have found one that was wide OPEN....clean and solder the red and white/yellow wires onto those contacts....also, remember that at ALL times a black wire OR a metal formed clip from the frame of the coil to the center contact is there, and so the 3 wire plug going to the sender under the rotor button, has a GROUND to the coil, what happens is the coil secondary then arcs to the yellow or red wires....and beleive it or not, the car will run, run like SHIT , but run.....the frame of the iron core is the ground for the secondary a la the old round ones....

pull that coil cover off that cap and eliminate those two sources first, then we go for the ign module, and if necessary that sending coil down under with the green/white wires goinginto the module....that puppy MAY be messed up with years and heat.....when I redo one of these dizzy's I change it, but you have to pulll the gear off, and slide the shaft outta there then the snap ring retainer....

you have a 7000 rpm race engine, yeh, maybe but I can assure you the HEI is fine for a street machine.....and from what I have heard about many other systems out there, it's about the best.....I have heard nothing on the net in 15 years to change my opinion....

SOUNDS like you BTDT with the fuel issue already, wish I had your knowledge when fighting my messed up gallon of fuel in the tank bottom....car runs like new now....funny how that is, feed it gasoline and it runs better than with water......I"d STILL be paranoid over that damn gasoline....I just can't figger how or WHY I continued to have a water problem since I been here, I just now stuck a locking gas cap on the car....

I"m about the believe anything about that water, including the ethanol crap....but for now, it's running ok....

:bonkers::hunter:

 

[AJ77]

Stock GM HEI coil in cap coils rarely go out.
It sounds more like the module has crapped out. Cheap and easy to change.
Do you have a VOM? You can test the coil.
It looks like this one,correct?

No, it is an HEI small cap with a remote coil, and it is only 1 1/2 years old. It is about the same diameter as an old points style dizzy, maybe even a little smaller. I think it is the same one used on a 90 Corvette L-98 with TPI. The coil is an MSD round oil filled Blaster 2. The distributor cap has a rectangular cutout in one side where it sits down over the ignition module. I've already changed the ignition module with no success. How can I test the coil? I have a meter.

 

[mrvette]

Stock GM HEI coil in cap coils rarely go out.
It sounds more like the module has crapped out. Cheap and easy to change.
Do you have a VOM? You can test the coil.
It looks like this one,correct?

No, it is an HEI small cap with a remote coil, and it is only 1 1/2 years old. It is about the same diameter as an old points style dizzy, maybe even a little smaller. I think it is the same one used on a 90 Corvette L-98 with TPI. The coil is an MSD round oil filled Blaster 2. The distributor cap has a rectangular cutout in one side where it sits down over the ignition module. I've already changed the ignition module with no success. How can I test the coil? I have a meter.

Ahh, you can test them old coils till hell freezes over, all you can do is a continuity test anyway, and then if the insulation internal is bad you not finding it on account of the coil resistance is much lower than a few megs of breakdown/carbon path....I never had any luck anyway....

you have a dizzy from a CAMARO, they needed that small diameter for I would imagine clearance off the firewall, that damn engine was crammed SO far back under them windshields, one reason I would never own one, same reason I hate Vx FWD crap....tighter than whale pussy under there, and that's waterproof.....

:rain:

 

[big2bird]

Stock GM HEI coil in cap coils rarely go out.
It sounds more like the module has crapped out. Cheap and easy to change.
Do you have a VOM? You can test the coil.
It looks like this one,correct?

No, it is an HEI small cap with a remote coil, and it is only 1 1/2 years old. It is about the same diameter as an old points style dizzy, maybe even a little smaller. I think it is the same one used on a 90 Corvette L-98 with TPI. The coil is an MSD round oil filled Blaster 2. The distributor cap has a rectangular cutout in one side where it sits down over the ignition module. I've already changed the ignition module with no success. How can I test the coil? I have a meter.

Okay. From the - term to the + term, (Primary), you should read .7 ohms on a blaster 2.
From the - term to the HV term,(Secondary), you should read 4.5K ohms (4,500ohms)
http://www.msdignition.com/Products...ent/8202_-_Blaster_2_Coil_Hi-Performance.aspx

 

[AJ77]

WELL, THAT SUCKS!!!! I just tested the coil and from - to + primary it read .7ohms and from - to HV terminal it read 4420 ohms. Back to ass scratching, dammit.

 

[big2bird]

That doesn't leave much
1)HEI module bad again
2)Miswired
3)Carbon tracking/spark scatter

Your black soot described maybe excessive carbon brush residue that is making your HV output spark all over inside the cap.
It's not a good condition anyhow. I would change the cap and rotor first. Use a good unit like Delco or NAPA. Do not use Niehoff crap from the Zone. It's trash.

 

[big2bird]

What is your CR and spark plug choice? Wires okay? Check for continuity in all wires. Ave resistence is 100 ohms/foot.

 

[AJ77]

That doesn't leave much
1)HEI module bad again
2)Miswired
3)Carbon tracking/spark scatter

Your black soot described maybe excessive carbon brush residue that is making your HV output spark all over inside the cap.
It's not a good condition anyhow. I would change the cap and rotor first. Use a good unit like Delco or NAPA. Do not use Niehoff crap from the Zone. It's trash.

#1-I'm on the third module?
#2-Nothing in the wiring changed
#3-third new cap and rotor from Nappa
CR is 9.8:1 and have both AC Delco 6 and AC Delco 5 plugs. Both sets almost new
wires are MSD 8MM and are reading about 55 ohms per foot? Same wires that were on the motor before the cam change.
My wife just told me to go ahead and order the new Accel Thruster DFI engine management system. As I said, it is sequential fire and fully diagnostic and programmable. I'm sick of messing with this one. I know it's not mechanical or fuel related. Only other thing I can come up with is maybe when they burned me a new chip for the cam change, they f*cked up the program??

 

[SmokinBBC]

What do the plugs look like?

 

[AJ77]

What do the plugs look like?

They are kinda wet black at the base at the end of the threads and the ground lug still has a bit of shine to it like a new plug that hasn't been fired yet. A couple have the ground lug a little bit brown closer to the electrode in the center of the plug. I just hooked up the coil again and ran the car for about 10 minutes and che resistance between the - terminal and the HV terminal went up from 4420 ohms to 4650 ohms. Enough to be significant??

 

[big2bird]

What do the plugs look like?

They are kinda wet black at the base at the end of the threads and the ground lug still has a bit of shine to it like a new plug that hasn't been fired yet. A couple have the ground lug a little bit brown closer to the electrode in the center of the plug. I just hooked up the coil again and ran the car for about 10 minutes and che resistance between the - terminal and the HV terminal went up from 4420 ohms to 4650 ohms. Enough to be significant??

Nope. Insignificant. Wires are good.