Hi!

Today I where in my garage doing some work on my camaro, just some small projects.

I thought I start her up and make her spin som in the garage, Turned they key and she turned over a couple of turns and jumped on.. Running pretty good..
Some small stubmle but that whent away when it went into Closedloop. runned her for ~5 mins turned her off..

Thought I try and start her again and then it just kept turning over and the engine shaked alot, kinda like it fired on the wrong cylinder or something hard to tell, during this the RPM needle jumped all over the place, from 0 to 7000 and finally when the engine started it throwed code : 42 and the RPM needle got stuck at 7000rpm (the engine speed was around ~900 by the sound...), had to rew her to get it down and working again...

Errorcode 42 is :
42. Fault at electronic spark timing circuit OR
42. Fault at direct ignition system OR
42. Fault at fuel cutoff relay circuit

I have checked the timing its at 6 deg. and its a new MSD 8366 Distributor.
Alot of times it starts good but sometimes it does this with the needle, jumping around, engine shaking during cranking...

I changed the ESC module last year, the stock one had name/number:
ANAJ
885431

New ESC module from Tpiparts:
ANRZ
16126761

I tested to put back the old ESC and it knda runned better.. But the new one says for 305, could that be my problem ?

I have changed the pickup and ignition module twice, but still the same problem occurs sometimes..

Any ideas where to go from here ?

I have checked/changed the starter, Timing is checked, Grounds are checked and cleaned (just in case) New ECM (1227165 reman) New Dual Blaster coil.

Got 1 video where you see how it acts when its hard to start...
http://www.alandsbrodata.ymex.net/film/hardstart1.mpg

Needle jumping around, engine shaking not firing as it should, and today I got errorcode 42 first time... changed ESC module back to original and it runned little better.. any ideas ?

 

Check your TPS. I had problems with my 88 that drove me nuts until someone on here suggested that I check the TPS. I just bought an 89 that was "running great" until the xmission failed. I got the transmission in and it would not run. After resolving ignition issues it still would not run. Rich smell, back firing, stumbling would not start and when it did it would not maintain a run state. No code to point to the TPS or MAF. A little while ago I checked it and it was at .64 instead of .54-.56. I adjusted it and now things are much improved and I will be able to drive it and see if I have more to troubleshoot.

There is an article on here for checking the cal of the TPS. It will take you about ten minutes to verify that it is working properly.

Good luck...driving weather is here.

 

Thanks for youre reply, I have the TPS set to 0.54 at the moment.
Tested with a VOM and thru TTS Datamaster.

Im leaning onto something with the EST or ESC maybe ?... but dont know where to start.
I have changed the most parts on it already... the problem has been gone for a while, but now it seems to be back... its not always its a intermitt (or how its spelled) so its kinda hard figuring it out..

When it runs, it runs smoothly and fine.. its just the starting (sometimes...)

 

No more ideas of what to test or check again ?

 

Greetings all the way to Sweden!!

You can disconnect the ESC (knock) module. If it is faulty, the engine will run better without it.

You also mentioned that the distributor is new and that you checked the timing. Please forgive my ignorant question but did you disconnect the timing connector on the passenger side when checking/setting the base timing?

Lou

 

I just finished downloading and watching your video. I see that she runs nice and smooth so I take back my question about the timing.

But like I said, you can disconnect the ESC module and see if things get better.
Also, if the ESC module is causing trouble, unplug the knock sensor (passenger side, in the block, above the starter) and see if things improve.

Hope this helps.
Lou

 

Hi thanks for response.

But can a bad ESC cause the hard starting ? cause thats the big problem.. Its hard to start sometimes, and the RPM needle jumps allover the board (from 0 to 7000rpm as the video shows)

I have tested 2 ESC modules, 1 brand new (AC Delco) and the stock one..
I also changed to a new knock sensor on the block (passenger side)

But is it fine to try and run it (to test) without the knock sensor ? and/or the ESC module ?

 

Yep, it's safe to start it without the knock sensor or without the ESC module.
Just don't drive it.

Lou

 

Aah oki i will try that, so that could be the thing thats making it hard to start sometimes ?

Can it be the cause of the RPM needle jumping around (betweek 0 and 7000 during crank to ?)

and be the cause of the errorcode 42 ? :
42. Fault at electronic spark timing circuit OR
42. Fault at direct ignition system OR
42. Fault at fuel cutoff relay circuit

Just to be sure before leaving for the garage, and if you come up with something else you want me to try to, just post it here and ill read it before going to my garage.

 

yes it can be the cause of the needle jumping, if the knock sensor is flaking out the computor will be going nuts adjusting timming, causing rapid idle adjustments, ect ect and gets caught in a loop

 

hmm... cause I have logged it with TTS Datamaster during crank.
And when the needle jumps like that it sends the RPM thru the chart and the timing shows 40+ etc.. The problem went away for a while so I thought it was solved..

but now its back, I will try and start it without the ESC connected.. I have charged the battery fully to, just to know its a 100% full battery.. Ill get back when i have tested again.

But why would it give errorcode EST ? isnt that a seperate thing ?

 

in these years the ECM does not have seperate a code for the knock sensor just the whole EST circuit. so You need to seperate it to see if it is the EST box or the knock sensor

 

Today I tried to start the car, full battery, ~22 deg celcius (inside the garage)
Turned the key and the RPM needle jumped little bit. Not as much as before..
Let her go into closed loop, shut her off and tried again, Now the needle jumped ALOT more and the car shaked. I turned her off and thougt.

Lets try and start her while pusinh the BRAKE pedal down.
She starts alot better, much smotter start.
So is it like on newer cars that you need to push down the BRAKE pedal while cranking ? never thought of this before but she started much better...
after 15 tries (good ones) she kinda wanted to turn for little longer ....

So the question is, shall the car always be started with BRAKE pedal pushed or dosent that matter ?

Havent tried to start her without the ESC module yet, will try that tomorrow and see if she starts better...

But the problem is like something is stopping the rotation, its hard to describe but the engine/car shakes when cranking and the needle jumps around its almost like missfiring when cranking, or could it be that something is stopping it turning ? but when it starts it runs smooth and nice, no sounds or anything....

 

this may be a shot in the dark but, large distributor cap or small? if it is small replace the cap and rotor, ?? this is a big problem on TBI trucks from 1989 to 2000. moisture gets in via a small "breather screen" in the bottom of the distributor, and look for bad wires.

 

I changed the distributor last year to an new MSD 8366.
I also bought new MSD SuperConductor 8,5mm wires.

I cleaned the rotor and cap just to be 100% no buildup is there.

I can try an buy another cap and rotor but its ~1year old and I only driven it 1000km since the change, and its inside in a warm garage during winter/bad weather days.

But I will check the cap and rotor again, thanks for response

 

Nope, no brake start safety switch or anything like that on our F-bodies.
If you can guarantee that every time you depress the brake pedal, she starts smoother, I'd say you have an electrical problem where the brake signal is bleeding off somewhere, causing a difference for the ECM and/or sensors.

Lou

 

The tach signal comes off of the coil. Its a beige colored wire with a gray inline connector. Shoot it to ground and see if you have continuity. Shake the **** out of the harness while youre shooting it. If you have continuity to ground at any point, then thats your problem.

 

Hi all!

Been changing the starter again, it was faulty, didnt engage as it should etc.
Could hang and make it hard to start. Have started it 20 times with the new starter, been doing pretty good.

Took some movies, for you to see (if you could help me out)
What you think, does it start as it should ? (sound/picture isnt the best but hopefully you see something)

The movies are listed in the "timeline" as I started it, first movie was the first start today, 2nd the second etc. 3rd movie was with EST disconnected.
Checked the timing and it was spot on 6deg.

Cold Start:
http://theking.joakimweb.se/z28/mpg/startcold1.mpg

Medium warn start:
http://theking.joakimweb.se/z28/mpg/...ediumwarn1.mpg

Start without EST (checking timing):
http://theking.joakimweb.se/z28/mpg/...kingtiming.mpg

Warn start 1:
http://theking.joakimweb.se/z28/mpg/warnstart1.mpg

Warn start 2 (longer clip with rpm gauge zoom etc. and stop/restart):
http://theking.joakimweb.se/z28/mpg/warnstart2.mpg

So does it start as it should ?
Battery fully charged, Starter is lined up as it should exactly as the manual said, is it good to go and dont think about it ?


EDIT: 17 May

3 movies from today to:

Coldstart 1 (first start today):
http://theking.joakimweb.se/z28/mpg/17maycoldstart1.mpg

Coldstart 2 (second, some minutes after the first one):
http://theking.joakimweb.se/z28/mpg/17maycoldstart2.mpg

Warn start (with some gauges showing etc, putting her in gear etc.):
http://theking.joakimweb.se/z28/mpg/17maywarnstart1.mpg

So what you guys think, good to go ?

 

3 movies from today to:

Coldstart 1 (first start today):
http://theking.joakimweb.se/z28/mpg/17maycoldstart1.mpg

Coldstart 2 (second, some minutes after the first one):
http://theking.joakimweb.se/z28/mpg/17maycoldstart2.mpg

Warn start (with some gauges showing etc, putting her in gear etc.):
http://theking.joakimweb.se/z28/mpg/17maywarnstart1.mpg

So what you guys think, good to go ?

 

I have the same problem.

Tach wiggling and shaking and code 42 error. Also when check engine lights up (it tach starts wiggling while i'm driving) the car will ping under acceleration.

Could also use some help at where to look for the problem.

 

IT was an bad ignition module at the distributor and a bad main power cable from battery to starter.

Check those 2 things and get back here :-)

 

could be a bad Knock sensor or your ESC is comming unplugged or shot as well, ESC tells the Ignition modual to retard when it hears a Knock if the sensor is unplugged it will advance off of the scale. jumpy tack could be a bad plug wire, (been there done that) unfortunatly it almost always dammages the modual hope this helps

 

Just wanted to say, i got the 42 code. What fixed mine was replacing the distributor. 100bucks but well worth it. Car runs 100% better. The sensors in the distibutor had currosion(however you spell it) on them.

 

Wanted to update that I have cured mine too by replacing the distributor.

 

I also solved the problem when I replaced the Ignition module and pickup in my MSD Dizzy.

 

I see no mention of it apart from the original post, you say the new module is for a 305 while you are pushing a 350. Please, if I should be corrected, let me know, but wouldn't a 350 have a larger knock count, of which wouldn't the module throw timing out of wack to try and compensate for a safe start/while running? Just want to make sure you are using a 350 knock sensor and module if necessary.

 

The ICM or ignition control module that is in the distributor couldn't care if it was a 302,305,350,383,400, etc. The spark map within the ECM's tune or .bin file cares.

 

Its a 350 knock sensor and a 350 ESC installed (now, was wrong ESC in the package from the start) But that wasnt the problem, the pickup and ignition module in the dizzy was bad. Thats why it acted so strange, MSD sent me new ones and its all working perfectly :-)

Those are changed now and its running like a champ again :-)