seanconnery89

Hello folks. I'm sort of new here and I am working on my dad's 1989 IROC Z with the 5.7. The car is all original with 84,000 miles. When he got it out of hibernation the other day it was running rough, to say the least and had the service engine soon light on. So I brought it to my house and began to diagnose it. Let me begin by saying this is by far the most complex engine I've worked on. So here goes:

I found the paperclip trick for the OBD1 port and read the code and it told me code 42 (the EST problem one). So I carefully marked the distributor cap and metal base with a mark on the engine so I could put it back, marked the plug wires, and took off the cap. I marked the rotor to the mark on the dist. base and the engine, and took out the distributor. I removed the dowel pin and the pole to get to the pickup coil, and the coil was trashed (there was bare copper unwound and degraded). So, to make a long story short, by the time I came up with a parts list of a new cap, rotor, pickup coil and module, it was cheaper to get a new distributor. So I got a duralast gold OE spec new distributor, lined up the new rotor and cap with all my marks I made on the old one and put it in.

The car turns over but will not catch spark and start up. I thought maybe I got the pole and rotor 180 degrees off somehow so I re-oriented it like that. The engine wants to backfire now, and that's where I stopped. Did I put the new distributor in wrong? Did I mess up the timing? I feel like I'm in over my head. Any help would be really appreciated.

jagdprcp

At this poijnt, the best thing to do would be to set the engine to TDC on the compression stoke of the first cylinder. You can test that by having some one rotate the engine while you have your finger over the spark plug hole. When it comes up on the compression stroke you will feel it push your thumb. Set the engine to TDC and see where the distributor is set. If it is not in the correct spot, pull it out and rotate it until it is where it is supposed to be.

Skeeeter

seanconnery89

Thanks for the advice, jagdprcp. I tried the thumb over the spark plug hole method, but as I have no one able to help me I did it myself. I have the front end up on jackstands so I got under there and cranked the engine with a socket and breaker bar and put my finger up to the #1 cylinder spark plug hole the best I could and I could feel the compression building and a hiss as I cranked. I inspected the progress with a mirror looking at the timing marks and the mark on the balancer. When I thought I felt compression building and the mark lined up with TDC I adjusted the rotor to match the #1 cylinder and corresponding plug wire. Now it doesnt want to backfire, but it doesn't want to start either.

I read that I could take off the valve cover and look for closing valves to indicate the compression stroke, but there's too much stuff to get out of the way for me to feel confident doing that. I guess it boils down to I have to get someone to help me so I can crank the engine and they can watch the timing marks and put their finger over the plug hole? Oh, and I bench tested the external coil according to the factory service manual with a multimeter and it appears to be fine.

OrangeBird

iTrader: (1)

So the car was running badly before , and after changing the distributor now won't run at all . There are really only a few likely possibilities here , First being that maybe there was (is) a bad connection in the area of the distributor that went unnoticed and has now been made worse being jostled around during the replacement , Or , and I hate to even think of this , maybe the new distributor is faulty ? It's a tiny percentage for sure , but there ARE brand new parts that turn up defective right out of the box . You sound like you know what's up as far as timing it correctly goes , so if I were you I'd start back troubleshooting at step one . Does it have power to the large pink lead ? Are all connections including grounds clean and tight ? I know you said the wire was hanging out of the original distributor and yes that could have caused poor running , but what of the fuel ? You mentioned that this car sat , is the fuel still burnable and reaching the cylinders in enough quantity to burn ?

PS , as to testing the coil with a meter ; While the meter will most certainly find a defective coil , the only "proof" a coil IS serviceable is to see it actually preform it's intended duty ! Yes , the Ohm check will find an open or shorted coil , but it will not find a coil whose insulation has broken down and is allowing electrical leakage of the type that reduces the needed spark to a useless fizzle !

mcgarnicle

iTrader: (14)

When you're cranking are you getting a rpm signal (tach bouncing? Or stationary?)

seanconnery89

Thanks for the help so far folks. I bought a spark plug tester the other day and tested a few wires and they are getting spark. I am also convinced that I have the timing set up correctly at 0 TDC. So once this damn thing runs, I'll fiddle with my timing light and adjust from there according to the service manual.

So now maybe the fuel sending unit (the pump and everything) has finally gone bad. The 1st owner told my dad that the car initially runs rough until it warms up and he chalked that up to only using it a few times a year. Maybe the fuel pump assembly is bad or clogged. I replaced the inline fuel filter when dad bought the car but I never tried to break it open to see if there was varnish or deposits. All the stuff is original too. Is there a way to test the fuel pump relay to see if it's working beyond the barely audible hum when the key is turned? This is a big-time beginner question too, but where is the fuse? It didn't appear to be in the fuse block. One more question: Do you guys use the "cut an access hole in the trunk" method, or pull the tank out from underneath? I'm a good welder, so fixing an access hole to as-new condition isn't a problem.

Thanks for all the help so far. I really want my dad to enjoy this car and it's killing me that I'm striking out.

OrangeBird

iTrader: (1)

The fuse for the fuel pump is under the hood in it's own little enclosure , and on my car it's mounted near the charcoal can . If you can hear the pump do the 3 second prime when you turn the key on then it's not the fuse causing the trouble . The thing here is , if you have proper compression , fuel , and spark , it's GOTTA run , so one of the three ain't right . Now , you say you checked the spark with a spark checker and it showed good ? Well then next in line would be a fuel pressure check , since just cause the pump hums is NO "proof" that it's actually pumping fuel in sufficent quantity to run the engine . Have you done a compression check on this engine ? I realize a "proper" compression check is done with the engine at operating temperature but since it won't run we'll take what we can get . The biggest thing here is that raw numbers don't mean as much as the difference in numbers between cylinders . 8 cylinders @ 120 each is a heck of a lot better than 7 @ 160 and 1 @ 120 ...

Oh , and , as to the fuel pump door

You will find folks on either side of the discussion to be downright forceful that their opinion is the only "True right way" . My belief here being that for a daily driver of no real historical importance a lil nip and snip to save dealing with the rotted in bolts of the exhaust and differential just may be the way to go if the bottom of the car is at all rusty/rotted . Now a mint TTA ? Well of COURSE ya wouldn't go cutting any holes into it cause that would reduce the value of a rare and expensive car . Just be DAMNED careful when even MENTIONING welding near a fuel tank that since it ain't getting removed , will be sittin under there with all of it's fumes just waitin for the "right" (wrong ?) spark to really ruin your day ......

seanconnery89

init4fun: Thanks for the continued info. I read on a turbo transam forum of a real nice way to do an access panel with a stainless cover plate and gasket and screws. That's how I'm going to approach that.

Back to the engine, where can I get a fuel pressure gauge? the schrader valve on the passenger side fuel rail back near the distributor is where this gauge goes right? Will some sort of adapter be needed to put the gauge on?

See, all this transpired 2 saturdays ago. I was going to take Pops car to a "cars and coffee" style meetup. I got it the night before and it did its usual hard startup routine (when I mean hard startup I mean 5 minutes of repeated starting and it would sputter and stall over and over until finally catching and eventually settling into idle). When it was finally ready to go it ran like a scalded dog. Saturday morning I went through the whole deal again, but this time it bucked and sputtered in 1st gear for 50 feet and the service engine light came on and I knew it was all over. I limped it back to my garage and have been going through all this ever since. Can it really be that a bad fuel sending unit issue AND a bad ignition issue (the service engine light was code 42 and everything but the external coil is brand new) have presented themselves at the same time?

OrangeBird

iTrader: (1)

Hi , as to the fuel pressure gauge , these can usually be borrowed from any auto parts supply stores that lend tools (Most do , they have you leave a deposit which you get back when you return the tool) and yes the valve you mentioned is where you check the pressure . Now , as to the possibility of multiple failures happening at the same time ; You said this car was in storage and any car in storage can have several things deteriorating from sitting at the same time . Just to use a for instance , the rubber fuel line that connects the pump to the sending unit in the tank can be rotting out at the same time the fuel itself is going bad . So you try to run it , it runs bad , you replace the bad fuel but by now the rotted rubber line has totally given up and no real fuel pressure is making it to the rail . I'm not saying that's your problem here , just a for instance of two things that can be failing at the same time . That's why when any engine won't run the standard routine is to check things like spark , fuel delivery , and then if the problem is not found it's a little deeper into things like a compression test and sometimes even a disassembly and check of the exhaust system , it's amazing how bad an engine will run if a family of mice have moved into the muffler when the car sat . (Along you come after months of sitting , fire it up , and end up with a muffler mostly clogged with mouse corpses , yep , I HAVE actually run into that one)

So just curious , HOW long was the car's "Hibernation" ?

seanconnery89

I forgot to answer an earlier question from mcgarnicle. The tach DOES bounce when you try to start it. I just went out there (just put my daughter down for a nap. Did I mention that I'm home on a "stay-cation? Ha!) and tried to start it again. The fuel pump relay clicks and the thing turns over beautifully. The tach bounces, the oil pressure goes up; it looks perfectly normal. It just will not fire. Oh and the ALDL widget reads no error codes either.

The first owner told my dad and myself that in the last few years (dad bought it march 2012) he only ran it a half dozen times a year cause he had other toys. Since my dad bought it he likes to drive it when we thaw out here in MD around april to around late october when the freeze sets in. Weekends or every 2 weekends if there's rain.

This has to be something so simple. I'm tellin' you man, 2 fridays ago I was carvin' corners, bangin' gears and chirpin' tires like Joe Dirt. The very next morning everything went to hell.

seanconnery89

Okay so here's an update. I replaced the fuel pump and strainer with new parts from Bosch. I completely emptied out the gas tank and cleaned it. The original AC Delco pump had the rubber boot that belonged around it mostly floating in thousands of pieces in the tank. The strainer was covered in that old rubber stuff. So I thought I had found my problem. I also went ahead and replaced the inline filter as well. I put 6 gallons of new gas in the now spotless gas tank.

The car will still not start. It cranks strong all day long. The tach bounces, The oil pressure gauge goes up. No service engine codes. I have spark according to the spark tester. I don't have any reason to believe that theres no compression. I replaced worn out parts with new parts. It does everything it should but start. I'm getting really bummed out now.

eseibel67

You have spark, are you getting any backfires when cranking? Is the spark strong enough to fire under compression?

Here is a flowchart with diagrams for code 42:

http://www.chevythunder.com/est_code_42.htm

seanconnery89

It doesn't want to backfire. As for the spark question, I followed the testers guidelines. I didn't know that the spark needs to be a certian strength to fire off the fuel/air mixture. So even if the tester indicated spark, it might not be hot or strong enough? When all this hooplah began, I bench tested the external HEI coil with a voltmeter and it tested good. Could the coil be bad but yet give enough electricity to have the spark plug tester indicate a good result? The coil is the only part I did not replace.

eseibel67

It is possible. It's harder to jump spark under pressure.

I wouldn't go out buying a coil just yet though, not sure if a weak coil would result in a code 42.

seanconnery89

I think it might be the other half of the fuel system that I havent diagnosed yet i.e. the fuel rail and the injectors. I really hope it's not them but what else could it be? Does it stand to reason that if the gas tank had all sorts of debris in it, that the debris would eventually make its way to the injectors? Is there an easy way to test the injectors? I've never taken an injector out before, much less tested one. How would I test to see if the fuel is making it up to the fuel rail with enough pressure?

mcgarnicle

iTrader: (14)

On the fuel rail is a black cap that covers a schrader valve, I think by the vacuum ports on the rear passanger side. Pull that cap off and hook a fuel pressure gauge to it, you should be able to get this at any parts store to rent or buy. I made one out of old AC lines and gauges. If you have enough pressure, I think TPI is around 42PSI, and it still isn't starting then you'll need to test that your injectors are pulsing.

seanconnery89

Is there any sensors that could be faulty and thus prevent the engine from firing?

90camaro355rs

ok sean, I have read this thread and wanna help, if you reset your number 1 piston to top dead center then set the rotor to point to number 1 plug, Then make sure that the number 1 plug starts there at the point of the cap, 18436572, I'm sure you know this.
Then if the car tries to back fire doesn't mean its in wrong just means you may need to turn the dist a bit, turn clockwise then counter clock wise to see if it will start, if it doesn't backfire or turn over hard, I would question you being on the compression stroke, it would be much easier if you made yourself a bumb tool, take 2 wires and a push button, connect one to power the other to the purple wire on the solenoid, then bump button until engine is at 0 deg top dead center. This will make it easier for a one person operation

90camaro355rs

yes it is possible, thing is it ran to your house, then the dist was removed so, I am thinking it is really in the dist timing.

seanconnery89

Yeah, me too 90Camaro. That's how this whole mess started. Working alone, I get under the car and use a breaker bar and a 5/8" socket and rotate the engine clockwise a little at a time while using an inspection mirror to line the mark with 0 on the brass plate. I had my dad stick his finger in the #1 plug hole to feel for building pressure as I cranked from underneath but because I'm rotating the engine manually I don't think the finger trick worked. I also tried to remove the valve cover to watch the valves closing to let me know TDC was coming around but I gave up because the cover doesnt clear the air conditioning hard lines, which I didn't want to disconnect.

So when I didn't hear the engine want to backfire, I performed the spark tester check and saw that I had good spark. My dad and I planned all along to do the fuel pump sometime this year, but when I saw good spark I logically moved on to the fuel system repairs. So that's where I am now.

90camaro355rs

you can have good fire yet not start if the dist is not in correctly, if your dad is there to help you then use the key to bump the engine over until your close to number one top dead center then use the 5/8 socket to finish it to TDC, then check the rotor, I am betting your dist is 180 off, if you get it to backfire then your headed in the right direction, just move the dist either way, you should be able to get it to start from there.

mcgarnicle

iTrader: (14)

Are you sure you're checking the right piston? #1 is drivers side front. I only ask because in 89 with the serpentine belt the AC is on passengers side.

mcgarnicle

iTrader: (14)

This may help

seanconnery89

Oh yeah that's the right cylinder indeed. I thought that was the air conditioning compressor right there that has 2 hard lines running out of it. I just realized that there is more than one belt. What does that mean? Here's a picture of the engine bay.

Is it possible for the engine to be aligned to 0 TDC and have it be on the exhaust stroke? 1 revolution from 0 TDC to 0 TDC equals either the intake OR exhaust stroke right? It's up to me to figure out which one. So it's possible I aligned to 0 TDC on the exhaust stroke and slid the distributor in place? If I did that, then I would need to go to 0 TDC manually again, get up off the floor and look at where the rotor is pointing, and if it's pointing to #8, then just pull the whole distributor out and line it up to #1.

See I've done this soo many times now that I think I've confused myself right into a big ball of stupidity.

mcgarnicle

iTrader: (14)

Hmmm I was under the impression all 88-92 f bodies ran the same belt drive, maybe changed at some point? Oh well doesn't matter. To answer your question, yes that is possible. The crank makes 2 revolutions for every 1 cam revolution.

jagdprcp

You can also pull the #1 spark plug and tape a short piece of light weight plastic like a piece of bread bag) or cloth over the spark plug hole. Then as you rotate the crank it will push the plastic out when it comes up on the compression stroke.

Then check to see where the rotor is pointing. That will be #1 even if it is pointing at the #6 plug wire. You can either move the plug wires or pull the distributor and put it back in the correct way.

Skeeeter

90camaro355rs

yes if your 180 out it will point to the number 6 wire #8 cylinder, I would not recommend moving wires, Bring the number 1 cylinder up on the compression stroke then check rotor, if it isn't on number one you will need to change the position of the dist, so the rotor is pointing to the #1 cylinder then make sure the wires are on the cap correctly, this should help you fix your problem.

seanconnery89

Thanks for the help so far. I'm going to try that plastic bag over the spark plug hole trick when I get the chance to work on it again.

seanconnery89

Okay, time for the latest update. I checked my positioning of the rotor at #1 plug against 0 TDC and I think I have it on the compression stroke. I am getting it to backfire all over the place now so I am definitely close. I went back after each backfire and loosened the dist. bolt and moved it counterclockwise a little each time until it was backfiring hard. Then I tried it clockwise and it still wants to backfire. Is there still something I'm missing or is this what I have to keep doing until I finally get it?

On a positive note, I think am beginning to see the light at the end of this epic tunnel!

eseibel67

Loosen the distributor hold-down bolt just enough so that you can adjust it, but also that it has enough friction to hold it's place without slipping away.

Turn it a bit this way and that while an assistant cranks the engine for you. After it fires, put it where you get the fastest idle until all the unburnt fuel gets cleared and the temp gets up. Then you can set the timing properly.

mcgarnicle

iTrader: (14)

Check that your wires are on the right cylinders also.

splitty

Your getting there.

You need someone else to crank the motor while you turn the distributor until it starts. If you cant get it to start and run some what smoothly then check to se if you are a tooth out on the distributor or that in all the confusion you have all the plugs wires in the right spots. Its amazing how easy it is to accidently grab the wrong wire and stick it on the wrong plug or terminal when you get confused. Let us know what you find.

90camaro355rs

looks like your headed in the right direction, as mentioned above you will need an assistant. First double and triple check wire placement, then move dist clockwise then counter clockwise a little at a time until it starts.

seanconnery89

Thanks for the info about a little at a time. Looks like it's time to rustle my dad off his duff and over here to assist. How do I know for sure that I can finally put the 0 TDC issue behind me and get the car off the jack stands and on the ground? With the current situation can I be sure I'm not 180 degrees off still? Will being on the exhaust stroke still induce backfiring? I sure would like to give my tip toes a break and set the front end down. When you guys mention move the dist. a "little at a time" do you mean like 1/8" each time the key is turned? Should someone be turning the key and cranking the engine the entire time I move the dist. or should we stop, move it again and then crank it again?

If and when this thing finally runs I'll need to time it I assume. I've read about disconnecting the single brown wire to make sure the timing light reads right. Is there anything else particular about setting the timing after it runs?

eseibel67

If you are out 180*, you will shoot flames up through the intake.

Put the distributor where you think it's lined up with #1. While cranking, turn slowly, about a 1/2" at a time until it starts.

Do not attempt to set the timing until the engine is warm. Disconnect the tan wire when setting the timing. After you are done with the timing, disconnect the battery to clear the code.

seanconnery89

Okay. I just went out there with my wife and had her crank it over while I turned the dist. slowly to the right and it did nothing. It finally backfired at the extreme right (I could also feel the wire harness going to the module from the main harness getting very tight) and I stopped there. Then I worked my way back to the left and it still did nothing. I've triple checked the plug wires too. What the hell else can it be? Now I'm really pissed off at this thing.

90camaro355rs

ok, first take a deep breath, getting bent doesn't fix anything, trust me on that one.

ok so if your for sure your on the compression stroke with the number one cylinder and the rotor is pointed to the number 1 plug. Then you could be off on the wires by one. I know this is a pain in the A@# , with your helper have them bump the engine over while you have your finger over the number one cylinder, then when it is pushed off then remove the cap and see where the rotor is pointing, if you bump passed the 0 mark on the timing tab, that's ok just turn it back with a ratchet, I am pretty sure you are still having issues with the dist position

90camaro355rs

you can also have helper bump it around until it starts blowing your finger off then finish it with a ratchet so you know for sure you did not go past the 0 mark. if you have to turn it that far to get it to back fire then your still off.

you may need to help line the dist up with the oil pump shaft so the dist will fall in and point at the number one cylinder.

if you look at the bottom of the dist, there will be a slot inside the dist gear, this will fit in the top of another slot in the oil pump shaft, if this shaft is not in the right position when you install the dist it will make your rotor off. you can use a long screw driver to move this shaft.

90camaro355rs

then line see where the rotor needs to point to for number one, look at the bottom of the dist see where the slot is located, ( direction wise) and make the shaft for the oil pump turn the same way, this will help with making sure your dist and rotor fall in at the right place.

I know this is a lot to read and remember, don't give up

seanconnery89

Okay folks. More update time. IT LIVES! Sure enough, all it took was some help from a friend interested in cars (not my wife who didn't want to get her hands 'icky') and we got it running in a half an hour. And it purrs oh so sweet. That thing runs like it stole something. BUT, it has stalled twice for no apparent reason; both times when going to stop the car like at a stop sign or something like that. Put the brakes on, put the clutch in, and kerplunk. It stalls out. NOW, looking back through what we did timing wise to get it running, it appears I forgot to disconnect the EST wire before setting the before TDC 6 degree timing and then disconnecting the battery to reset the computer.

Is this why it may be stalling? I think it probably is, and I will be redoing the timing with the correct procedure hopefully in a couple days. I don't have to start all over at the very beginning of setting the #1 cylinder to TDC hooplah though do I? I'm planning on disconnecting the EST wire, starting the engine, letting it get to operating temp, and timing it right then and there. After the timing is done, should I let it continue to idle for a while before shutting it off and disconnecting the battery to reset the computer?

I can't thank all of you enough for your help. I'm glad I stuck with it cause now I've learned more.

90camaro355rs

so glad to hear it lives, if memory serves me correctly and please someone correct me if I am wrong, you need to warm engine to operating temp, unplug tan wire at cowl, then set your base timing with a light, the reconnect tan wire.

let us know what you did so others that read this can try what we suggested and you did to get it to start. May help another down the road.

Congrats to you for sticking in there and getting another set of hands to help you out.

seanconnery89

What finally worked was that I was able to get help from a friend who fools with cars too. He put his finger in the #1 plug hole and I cranked the engine over with a breaker bar until he told me he felt a definate buildup of air pressure. Thats when we knew that the engine was on the compression stroke. then I rotated it around to 0 TDC and we went from there. I took the dist. cap off and found I was off 180 degrees from my previous efforts. I slid the whole dist. up just enough to move the rotor and shaft around to where #1 cylinder should be. Then we took a small square and put it on the rotor and marked the intake (this mark was about 1/2" off where my original mark was when I was working alone). Then we put the cap on and lined it up with that mark. The damn thing fired right up.

Then we turned it off and unplugged the EST wire and timed it to 6 deg. BTDC according to the service manual. Runs like a beast now.

I guess the biggest thing I can take away from this adventure is to get a friend to help you. It took us all of about 90 minutes, instead of 6 weeks of me toiling on and off alone.

That being said, I do have one final question. I went back and looked at the timing yesterday out of my own curiosity and noticed that the engine has moved the timing. I dont remember in which direction the timing moved but it has moved. I've gone on a few joyrides and out to get a fresh tank of 93. When we timed it I made sure to torque the dist. bolt to the service manual 27 ft. lbs. too. Is this normal for the timing to move?

90camaro355rs

what your forgetting is your timing will be different with the est wire hooked up, if you torqued the dist bolt down, your dist hasn't moved.

I say drive the car enjoy the work you have done, remember the knowledge you have gained.

Most of all Thank your friend for helping you!

seanconnery89

There was one more thing I forgot to ask about. Now that it runs, and runs great, there is a particular circumstance when it stalls out for no reason. I was going to ask this as a new thread, but I thought it might be related to all the work done.

It seems like when I come down a hill preparing to stop like at the end of a driveway, and I take it out of gear and come to a stop; it dies right there. It fires right back up with no hiccups, but this is a problem. To make sure it wasn't just a random thing, I tested my theory. I went down my dads driveway 3 times, and each time it stalled. I creep down the driveway in 1st gear, get almost to the bottom, take it out of gear, apply the brakes, and the car comes to a stop and stalls out. Then I cuss at it and it starts right back up and I'm on my way. Whats this all about?