hawkdriver

My wife drives that...I'm at an Army school in Alabama for two months...going home on the weekends...I'm stuck.

Z28GEN3

Seem to havea similar problem on mine BUT its TBI, 305.

Nothing has changed from 6 months ago when it ran. I had turned off VATS on the chip 5 years ago and it ran fine. I read the flash chip last night and everything looked good.

order of goodies:
I swapped in an AT trans, then lost my ignition key in the mix of new transmission parts and rebuild parts.

So I swapped out ignition locks, for a non-VATS key from my original column (keep in mind I have VATS turned off and also have a resistor in place).

Then:
As my S**t luck would have it the {2nd} fuel pump died at the same time I lost my key.

I didn't know it at first so I primed the oil pump that day thinking that if it started-having oil everywhere would be a good thing.

Now:
So i got new fuel pump in and it turns on and I can smell a hint of gas, but nothing rotates, seems funny that the starter would just die with less than 100 starts on it.

And I've recently installed a rebuild kit on the TBI in addition to all the other stuff.

security light comes on then goes off like it has before, if I turn the key to "on" my fan comes on and then eventually oil pressure gauge moves without the engine rotating dunno why I find that weird but it doesn't seem right.

Ive tried to read and do as much as possible before resorting to posting, at witts end now.

7 years of this

Chevy8588

iTrader: (1)

remove your battery cable, load test your battery, if your battery tests good, clean your terminals and cables and re attach them TIGHT, then try it. low voltage doessome funky sh-t to these cars

Z28GEN3

Still working on this, the starter tested out to be good and so did two different batteries and connections. I need to check into the ignition switch not the lock-I forgot that was there.

Chevy8588

iTrader: (1)

check your grounds and for any eaten wires by critters

camaro_doc

want to give an update to all i am still in the process of working on the IROC... i only get to play with it on sundays anyway i am in the process of mounting the MSD 6AL box will post some pics sunday night. I have a coil that is a GM Dual Connector style with the small HEI Cap.

WileECoyoteSr wrote...
"Camaro_Doc, I agree with Chevy 8588. Mine was the magnet pickup in the distributor but the ignition module is a better first bet."

So is all this under the distributor Cap? I have never messed around with a third gen that had a external coil with the dual connector on it. MSD makes a adapter harness that makes the 6AL install a breeze! does anyone know if by installing the MSD BOX will that bypass the ignition module?

Thanks for all of the help, I wish I could get this done quicker... Is anyone close to Gettysburg PA 17325?

Thanks

Matt

Chevy8588

iTrader: (1)

I doubt the ICM will be bypassed by the 6AL, and yes, it IS in the cap

camaro_doc

OK Good deal so it is off to autozone for a new icm... i will also get the pickup assy just in case..

will post up some results Sunday

Thanks

Matt

camaro_doc

Well heres the update...

1st heres some history of the car...

90 IROC origannaly a 305 TPI w/ a 700r4 motor had a bad knock. so it had to go...

Swapped Motor 350TPI from 91 Z28 and Jasper 700R4 from a truck.

Converted to 3.73 posi disc rear from 91Z28

All wiring harness and electronics are from 90 IROC

Computer is from 91Z28 has a hypertech chip in it.

Motor has some head work, a mild cam, and was rebuilt at one time but not anything extreme.

I drove the 91Z28 before anything was swaped into my 90 iroc)and its accident... and it ran awesome! Never had any issues. (this was the previous owners car he bought the 90 IROC from me and swaped everything from his wrecked 91Z28 to my 90 IROC) After he did the swap he called me and asked if i wanted to buy the IROC back, so i have owned the 90 IROC twice.

Bought car back and drove it 20 miles home, car was loading up really bad and was getting way to much fuel and drove like crap. previous owner had taken out stock 350 injectors and put in bosch pink tops. The car sat in my yard for about 8 months and had always started untill now. All of the sudden this no start issue has occured. I pulled the pink tops and put in a set of rebuilt and flow tested 305 injectors. I raised the fuel pressure to compensate.

I did all of the injector swap AFTER THE NO START ISSUE OCCURED.

Today I DID THE FOLLOWING:

put in new battery

replaced ignition control module

cleaned termanals on cap w/ emory board

cleaned rotor tip w/ emory board

re installed plug wires to make double sure they were wired right (they are)

still no start!

Check engine light is on (dont have a obd1 scan tool or i would say what the code was) and security light is on.

I dont think that the vats system is functioning properly because when you first try to start the car, the light is off the fuel pump primes and the car cranks. Then after the second starting attempt the security light comes on but the car will still crank and the fuel pressure is still present.

I put my timing light on to see if I had spark while cranking and i did. I had spark with the security light on and off.

I pulled plug #3 to see if my plugs were fouled, it was black but not horrible. I cleaned the spark plug with steel wool and it didnt make a difference.

I am really stumped here and dont know what to do next. Wile E Coyote said that his car wouldnt start due to a bad pickup assembly, could this be the case for me? I have one to put in but didnt want to do it if not nessicary. I dont get it because i always thought that if you have air fuel and fire the car would run.

The only thing i can not verify 100% is that the injectors are firing. I can smell fuel when i am cranking, i see pressure on the fuel pressure gauge, and the spark plug smelled like fuel when i had it pulled before i cleaned it

I hope someone has the answer to this issue. My goal is to have it running by January 1st because it will be 20 yrs old and I can put historic tags on it, plus then and it will be inspection & emmision exempt!

camaro_doc

Here is a link to a great video on how to bypass the VATS system. Has anyone done this?

camaro_doc

**** heres the link http://www.youtube.com/watch?v=AKfn7J9CeZM

Billy Boy

Hey Guys
Can someone help me out?
I have read WileECoyote post from top to bottom. I see where WileECoyote said he replaced the distributor.
I am not sure if this is the same problem that everyone else is having.
I have light at the NOID, Spark at the plugs and 44psi at the rail.
It doesn't make since, it should start
The only problem I had was a slight miss and it was very intermitting, my mechanic never could figure it out so I decided to take it to a dealership, they told me it was two bad injectors. I had them changed out and that lasted about a month and the problem was back again. So my mechanic and I decided that maybe there was one more bad injector, so he decided to replace all the injectors. And now I have this problem
Only starts with Starting fluid. And it will start every time after that only for a few days.
This Problem started after we replaced all the Injectors
I don't see how new injectors would have cause this.

We replaced Fuel Pump, Oil Pressure Switch, Coolant Temperature Sensor,Oil Pressure Switch, Throttle Body Sensor and Connector's, Plugs, Plug Wires, Fuel Injectors, Fuel Relay.

Could it still be something in the Distributor, even when I have light at the NOID?
It still sounds like the Injectors are not opening even when I see NOID light pulse.


ANY HELP WOULD BE APPRECIATED

y84pauloflondon

Everyone on here had different problems, 5 or 6 different cars all with different problems! The dealer told you that you had 2 bad injectors/ after replacing those inj. your car ran fine for a month.....Right? Then your problem came back?!?!!!!

Did you ever try testing the injectors yourself? (Ohm test them!) If you don't know how, just go on YOU TUBE.....Type in "fuel injector ohm test", there is a video there that showed me how to do it!

Just a guess, but I wonder if the injectors are fine, but you are not getting the proper volts/watts to the inj. Either way, it was when you messed around with your injectors things got worse!- Electrical Problem.......

Z28GEN3

Well, starter is back on, and column is together and I have the ignition switch off the top of the column-out I tested it, cleaned and greased the contact prongs and its still not sending power to the starter. Only other thing I can think of is the VATs is acting up even tho there is a resistor in place. will have to dig around more to find out what else is messing with me.

Crappy weather sent me indoors.

Chevy8588

iTrader: (1)

it would sound to me like your vats module is screwing things up, I am not sure how VATS pass-key 1 works, but I know on VATS pass-key 2 depending on the system it will do one of two things, either A - allow crank but kill injectors, or B - kill crank. just becuase VATS has been edited out of you're prom does NOT mean that your VATS module can't cause issues.

Z28GEN3

Finally got it, narrowed it down to a "Neutral Safety" switch, I spent 2 hours today ****ing with the ignition, bypassing the starter enable relay and the only thing it was...a .50cent switch was messed up.

y84pauloflondon

So does that mean your car is up and running? Have you been out for a test drive yet?

Chevy8588

iTrader: (1)

lawl, you never said your car was manual!!!!!! thats the FIRST thing i would have said then!

Z28GEN3

auto-manual valve body on a ratchet shift. at any rate it half attempts to fire, coil is good, suspect the dist. cap went bad, will buy a new one next time I run to autozone.

Z28GEN3

Well my luck is kinda crap now, I've got pull the stupid tranny again and see why the pump seal to trans case is leaking (not the pump to convertor seal). Have to wait for help removing it though to many injuries to muscle it myself even with the proper tools & jacks.

The car does run really well though, the relay for the N, P switch is acting stupid but it functions.

Chevy8588

iTrader: (1)

wow man, sounds like 2009 is rearing its crappy head on you too. how do you know you are leaking from the pump seal is peaking? and furthermore, i do not think i have EVER seen a pump seal on an R4 leak.... as for droppin the trans, if you drop it onto 2 sideways skateboards and jack your car up really high, it slides out REALLY easy :P

427F-Bird

iTrader: (1)

I'm having my own no start issue now. 1991 Formula. 305 TPI with a 5 Speed. The other day i decided the car needed a tune up. Cap, rotor, plugs and wires. So I got everything changed, and now I have no spark. It cranks, its getting fuel, but no spark. None at the wires, went to the coil, no spark at the coil. The two wires that plug into the coil have power, and the wires that go from the coil to the ICM have power, but its like nothing is triggering the coil to fire. I removed the ICM and had it tested at autozone, and they said it works. Any input on what else there is to check would be greatly appreciated. I am pretty much out of ideas at this point. Sorry if this was already covered and I missed it. Thanks again for any help.

y84pauloflondon

You have the same problem that WileECoyoteSR had by the sounds of it! I believe it was his "megnatic pick" THINGY, which is located inside the distributor, that was causing his problems.....READ pages 1-3, all the steps he did should be posted there, including part name, part number, and of course, the symptoms.

READ his posts, that should REALLY help you!!!

y84pauloflondon

If this works, PLEASE update us and repost!!!

427F-Bird

iTrader: (1)

Edit: I guess more accurately, how do i remove the capacitor cover and capacitor, and then the pole piece, cause there is a cover over it that im not 100% sure how to remove.

How do I go about removing and replacing the pick up coil, seeing as the two manuals i have show an HEI distributor. It says remove 3 screws, but there are no screws to remove. Could anyone tell me how to do this, or will I just have to replace the distributor?

rgarcia63

If you know, or suspect that this is the original Dizzy then I'd suggest replacing it.
If not reply back and I'll help you disassemble it.

427F-Bird

iTrader: (1)

It was the original Distributor. Replaced the whole thing. I appreciate the help. For reference though, how would one go about dismantleing and replacing the orignal distributor to replace just the pick up coil? Is it even possible?

y84pauloflondon

I would suggest sending WileECoyoteSR or Chevy8588 a PM since they know how to dismantleing the distributor. Sorry, I can't tell you myself, I've never then it!

Did you read the first 3 pages of WileEcoyoteSr posts like I told you to do???

427F-Bird

iTrader: (1)

I read them before, and it seemed to be a similar issue, so it was helpful, but i don't know if i just missed it, or if they didnt say anything about replacing just the pickup coil. Just the same though, this thread was very helpful.

rgarcia63

True, there are no screws to remove unless they' re counting from the removal to disassembly which would be in the following order:

• One hold down bolt.
• Two distributor cap screws.

I assume you already have the dizzy out and the cap removed, no need to remove the rotor.
Now remove the roll pin that holds the gear on, remove the gear then, remove the shaft from the housing giving you access to the pick-up coil. Easy Huh?

FYI - Never replace a Dizzy without checking that the length of the section that goes into the motor is not more than, or less than the original, it must be identical in length, longer can be fixed by shimming, shorter is just no good.

y84pauloflondon

Well try PM'ing them both! But I DO KNOW that WileE's megnetic pick up "Thingy" was his problem. It must of been mentioned later on in this thread somewhere!!!!!(pages 4+ maybe), but it is in there!!! If I find some time tomorrow, I'll try to find those posts for you! And maybe even a part # too. And I'm pretty sure that it was NOT an expensive part to replace.

But then again, can you really put a price on a perfectly running car?

Don't worry, your almost there!

y84pauloflondon

ANY UPDATE?????

gm muscle

Hey guys,

I've been keeping up with this thread and it seems as though you guys are still hard at work, diagnosing/ fixing problems. Good for you!!

Just an update:
Everything is running great! I did have to replace the bat, alternator, and MAF, but my car has fired up on the 1st time-every time!
This is the 2nd MAF sensor I've replaced in four years.

Does anyone know if these things can be rebuilt? Those damn things aren't cheap!

y84pauloflondon

They(MAF) can be cleaned with Air Intake clear, but as far as I know, there are No rebuild kits. Remanufactor MAF sensors are sold, and are the cheapest way to go instead of buying new. New will cost you $1600.00+, reman costs $100-$300.

y84pauloflondon

GM Muscle: Glad to hear your car is running good!

racethesunlive

Just want to thank everyone in this thread for following through with their answers... After reading through all these no start stories I was able to get my own 92 camaro to start and I'm up and running again thanks to you guys!

y84pauloflondon

Glad to hear it! But what was your problem??? (DETAILS PLEASE!)

Chevy8588

iTrader: (1)

yea what happened? keep this thread alive! I wanna see this thing eventually make sticky!

racethesunlive

OK here's my no start story:

While cruising down the highway one day my car just stalled, completely dead, and I had to watch the RPMs drop to 0 as I tried to coax the car back to life. Mashing the pedal to the floor and going into neutral didn't make a bit of difference and I knew I had to pull over fast. Well while on the shoulder I noticed I still had full lights, radio, everything... the car was even cranking, it just wasn't catching and refused to start. Thinking I had just lost my fuel pump I called for a tow and had my car dropped off at my place where I could investigate further.

So the next morning I hop in the car, turn the key, and the first thing i notice is that I can hear the whine of the fuel pump going. Whew, maybe its just a sensor that died I thought to myself. Because I could hear the whine of the fuel pump at start I knew my fuel pump relay was fine. So to make sure I was holding pressure in the fuel rails I turned the ignition several times... building up PSI without cranking the engine. Then about five minutes later I unscrewed my gas cap and heard the hiss of pressure releasing so then I was sure my fuel pump had survived and was ok.

Next steps involved testing the igntion. I grabbed my timing light and hooked it to one of my ignition wires. Turning the engine over yielded no sign of light or spark so then it was off to dig through my ignition. Because I wasn't getting a security light up on the dash, and the only SES code i was getting was a code 12 (good ECM). The only things left to check from there were the ignition coil and the ignition control module and so I picked both up for around $50 total at the autoparts store.

Long story short after replacing both the coil and the ICM (I'm not sure exactly which one failed but im guessing ICM) she turned over and fired right up. Reset the timing with my timing light and gave her a few short trips before today where she just made a 50 mile run! Not a single stall or SES code in sight! And so once again thanks to everyone in this thread for all the help.

y84pauloflondon

Congrats! I think this is the first No Start thats been fixed with a new IAC and/or Coil.

I believe that makes 7-8 cars fixed with 6-7 different No Start Problems. Keeping in mind the countless others that this thread has helped but was never posted!

**The Moderator should REALLY consider making this thread a Sticky!!!**

WileECoyoteSr

Hello all. No. I didn't fall off the edge of the world. I parked my 91 Z-28 on the side lawn for the winter because I was forced to keep the brand H car in the garage for daily job hunting. Now that I have a new job, haven't had time until now to dig the Z out of the snow bank. (Actually a string of 40 degree days melted what had looked like a drift back into a Camaro. I'll bet some of you purests are gritting your teeth about putting her out in the cold. But looking for a way to put food on the table changes priorities a little).

Still have the hesitation warm or cold. But I haven't had a chance to test the new TPS. How is that done, by the way? Do you needle probe the wires? Or unplug the wires from the TPS and test at the formed plug?

Congrats to all those who got their's running right.

And by the way. Just for the record: my no start WAS the magnetic pickup inside the distributor head under the ICM mount plate. And since it was riveted on and the whole distributor may have been original to my quarter million mile car, I chose to replace the entire distributor assembly as suggested taking care to make sure the new OEM style replacement was not only the exact length, but also the same gear tooth count as the old one.

It has started every time since. Just runs rich and hesitates. Oh and that pesky jerking feeling at 40 mph.

TZFBird

I took a twist-tie from the bread and stripped the plastic off it. It is such a thin wire it slips right down next to the wire in the plug and you can check the wires while still plugged in to the throttle body since you are reading voltage. You can either use 2, or just cut one in half. Just make sure you're not shorting to anything or this may alter your readings.

I'm having a similar jerking when I let off, but I've attributed that to the rearend/gear change while using the stock converter. I just need to get the new converter installed and see if that fixes it.

y84pauloflondon

HOW TO TEST/ADJUST TPS: (twist-tie is a good idea!)

1) Install three jumper wires into the TPS harness connector.(twist-tie)
2) Turn ignition "On"- (engine NOT running)
3) Connect voltmeter to the terminals marked A and B on the connector(the top and middle terminals)
4) TPS should read 0.54v-0.56 volts......IF NOT
5) Loosen TPS screws turn clockwise or counter clockwise to adjust TPS readings.
6) Once you have 0.54v-0.56 volts, tighten screws.*
7) Turn ignition Off, remove jumper wires from TPS.
8) Start the engine(30 seconds running), and them turn it off. The IAC valve will automatically resets itself.
9) Your DONE!

*Note- Ex. A setting of 0.40v is lean, A setting of 0.66v is too rich.*

I'm not a mechcanic and this was very easy to do!

Source: Shop Manual.

WileECoyoteSr

All cudos to Paul in Ontario! y84pauloflondon's TPS voltage test instructions were great - except -turns out the 91 Z-28 5.7L TPI doesn't seem to have an adjustable TPS. But it was a good next step to check for my engine hesitation and rich running symptoms. A suggestion I have for the wires to test it? I cut a 6" piece of telephone 4 wire cord with solid copper core. Gave me a red, yellow and green wire to use on the TPS harness connection and the solid core stays where you put it yet fits between the connector and the TPS terminal. (See honey! It pays to be a pack rat!)

Now I have to admit that I bought and was going to install a new TPS today before I realized I was testing pin 1 (top) against pin 3 (bottom NOT middle as instructed- oops) and got 5 volts which is correct. But I replaced the TPS anyway and notice the air valve position between the old TPS and the new one was definitely different.

My digital VOM only goes to tenths, darn it. And I've got a solid 0.4? volts key on engine off now. Started it, ran it, and it doesn't hesitate coming off the stop signs. I had to cut my test drive really short because the mist is going to turn to sleet any moment out there.

I realize Paul mentioned that .4 volts is lean and .6 volts is rich. The screw in the front of the throttle body where the air valve rests at idle is capped in the back and not adjustable in its OEM state. I fear trying to drill the cap out to see if I can adjust the screw. Anyone know if that cap can be drilled/pulled off without screwing up the system?

I'll update you all when the sun comes back out later this week. But I think Paul helped me solve my hesitation problem. Maybe the Gdaughter is going to get her dream car after all.

WileECoyoteSr

By the way, someone commented that this thread had helped a number of cars and had been viewed like 2,500 times. As of my log on today that's more like 6,808 times. I hope that those who viewed it have been helped by it. And again. Thank you all for your input. Just remember: THE ONLY DUMB QUESTION IS THE ONE YOU DON'T ASK. Just be sure to give us the whole truth about your car. If not stock, how's it been modified. What is it doing and under what conditions? What have you tried so far? There are a lot of car crazy people on here with big hearts and a lot of experience that they'll share freely if you show them respect.

TZFBird

If you go adjusting that it will change your TPS voltage, however it is going to change the amount of air at idle as well. Your IAC will adjust to compensate for this though. I know TBI has a stepdown table it runs through to warm up faster acording to coolant temp. So in the winter I would start out idling at nearly 1500rpm. Not good when parked on ice.

I was having a hard time finding a balance between TPS and IAC counts at idle when tuning the new engine. If you do go adjusting the throttle stop screw, make sure you do it at operating temperature and be sure to check the IAC counts when done. If you adjust it and it cannot close down enough, you could end up idling higher and the computer will constantly be trying to reduce idle.

WileECoyoteSr

Regards my worries about my injectors causing the stumbling or hesitation. Checking the resistance was as easy as the YouTube video portrayed! Check me on this but I have 1=15.5, 3=15.8, 5=15.8, 7=15.8 and 2=15.8, 4=15.7, 6=15.7, 8=15.5. Not 14's like Paul had. But still within .5 of each other not only on the left side, and the same on the right side, but left to right as well. Looks pretty balanced for a TPI to me. I should be okay to run with these, right?

Man I'd love to get some good weather around here in Kansas so I could blow the gunk out of the exhaust pipes!

y84pauloflondon

Actually, I tested the injectors when I had problems this summer, ALL my injectors tested out at 16 ohms.....All of them, not even .5 off!

But, your right, your injectors are all in the .5 ohm range, so there good!

y84pauloflondon

As long as WileE has his voltmeter hooked up to the TPS while turning that screw, he can keep an eye on it and stop turning it at 0.54v.(avg. range settings and a good starting point)

"Your IAC will adjust to compensate for this though..... " Thats fine, you want the IAC too reset!

As long as he doesn't go crazy turning the screw over, he'll be fine.

***Usable TPS adjestment range can be from 0.46v-0.62v, keeping in mind of the lean and rich range***

animute

I don't know if this sounds to simple but this sounds like partially clogged fuel filter, check under the car.