what is it and how can i fix it? is it related to my crazy stumble at WOT and partial throttle cruise? got an 89 lb9 that's gonna make me pull my hair out!

 

well it's obviously fuel related then, buy a fuel pressure gauge and see what it reads when key is in the on position after the fuel pump primes.

if you dont hear the pump kick on then it's either a bad pump, bad wiring or bad relay (usually the pump on gms).

 

code 42 is the EST though, that sounds timing related to me. i've got good connections everywhere, double checked my dizzy, my coil, my plug wires, it's got new plugs (NGK's, did i goof on this brand? never had a problem before), i checked and rechecked my knock sensor and my brand new o2 sensor. it's got a new fuel filter, old one i could barely blow through.

i put a can of seafoam in the tank sunday, but i was concerned i may not have gotten enough fuel in the mix. so i filled up (still running 87, previous owner never ran anything less than 93.) then i realized that the timing may have been advanced, so i got out my trusty timing gun, but it was set at 6* advanced. i bumped it down 1* and put some 104 octane booster in it (had some laying around) since i did realize that the PO only put 93 in it. so now i've got a conglomeration in my fuel tank and i'm not sure what's causing what!!!

fuel pump works...i do need to get a new fuel pressure guage. the little one that's on the intake put on by PO is fubar.

i'm thinking at this point i just need to run it out of fuel, put in 93 and see how it acts. i'm considering a late night run to the ATL just for this, hahaha!

 

you know you wanna stick a carb on it

Code 42 is Electronic Spark Timing(EST)

Id have a look at the ignition module.

 

inside the dizzy?

 

Ya, should have 2 connectors going into the back of it.

 

i think i'm just gonna replace the dizzy. the hold down screw holes are all stripped, i've got they dizzy cap held on by one of the hold down screws that actually works and then a zip tie. pretty ghetto fabulous. but also, inside, all the contacts on the dizzy are all corroded and everything. i work at a parts house so i can get a good deal, and this will kill a few birds with one stone.

 

I just sold my TPI distributor with msd cap/rotor for $25...but oh well those parts should be pretty cheap.

 

my bad all my comment was meant to be on the post that says *will only start on starting fluid*

not sure how i ended up posting it here, i know nothing about the est lol.

anyways sorry for the confusion and g/l with your problem m66

 

ok, so i've got a code 13 as well. the code 13 was there before the code 42. it says the o2 sensor is reading lean at cruise. i replaced the o2 yesterday as well as the fuel filter and pigtails to the coil. the old o2 sensor was in bad shape so it was money well spent, but it didn't clear the code.

the car has an AFPR on it, but i don't know whose brand it is. so i don't know if it's working correctly. the gauge i have on it (put on by previous owner) is not working, so i'm gonna pick up a new fuel pressure gauge as well.

i picked up a new distributor, cap, and rotor for $101 and change, so i didn't get hurt. i'm gonna put that in tomorrow or friday (got a new th350 going in the white car, yeah, it's more important, lol!) so we'll see how that goes.

anything else that might cause a code 42 and/or code 13?

 

Take a look at this page... http://www.asashop.org/autoinc/may97/techtips.htm
When I had this problem I checked every thing..All the wires in the ignition system , new ignition module and still had the same code....
Then I changed the ecm...and no more code 42 :-)

 

just put a new dizzy, cap, and rotor in it...still the same problem occurs. i'm getting a little frustrated. i have an l98 ECM at my house that i could plug in, will it work to diagnose my problem?

 

ECM swap did nothing.

 

alright, i'm scratching my head big time with this one. here's what i've done so far:
-fuel filter
-o2 sensor
-ngk plugs
-accel 8mm wires
-distributor
-cap
-rotor
-accel super coil
-new pigtail going to coil from ecm side
-just went and got a new fuel pressure gauge since the old one wasn't working any longer (great deal from summit by the way, liquid filled gauge 0-60psi for $20!) and some braided line so i could route it up to the windshield so i can get a better look at what's going on. found that the fuel pressure was only at 33psi! i unhooked the vacuum source to the afpr and the fuel pressure shot up to 42psi. so i putted around the neighborhood and found it had done nothing for me. grabbed a timing gun thinking maybe when i put my distributor in, i hadn't gotten it quite back to where it was, but to no avail, the timing light isn't working. the distributor is definitly close enough to make the car run right though. i hooked the vacuum source back to the afpr and adjusted fuel pressure up to 45psi. still nothing.

i'm letting the car cool down right now so i can pull the spark plugs and see if there's something going on there that i don't know about. this thing absolutely will not run right any longer. i'm pretty frustrated with it so far.

 

If the fuel pressue was only 33 psi, there's definately a problem on that end. Considering you've gone trough the ignition system, look at the pressure as you drive using that new guage. Remember though fuel pressure isn't everything, the guage doesn't measure the injector flow, you may have a stuck injector. Believe it or not, the TPI injectors, especially the crappy 19 lbs'ers that came on the lb9 cars can cause a lot of driveabity problems.

 

i got a set of l98 injectors sitting in a parts car, but no way to tell how clean they are. probably more gummed up then the ones i have in the car currently. i'm just kinda starting to run outta money at this point...i'm hoping to get by with what i have. is there anyway to clean these current injectors or maybe the l98's?

i pulled the plugs outta the car and they all looked OK. they had a little black to them, but mostly a darker brown. not the nice light tan i was hoping for. but you could tell that they were still firing. a couple of them were gapped incorrectly, and #6 looked like i had tapped the electrode a little to hard against a head bolt or something while i tryed to finagle it in, cause it was definitly gapped like .018", lol! i started it back up after i got all the plugs back in (remember, these are less than a week old plugs) and hooked up (also noticed a slightly loose #6 wire) correctly the car really sounded alot better. but then the car died. we fired it back up only for it to die again. and when we tried to fire it up once more, the starter really sounded weak, and then finally i got nothing outta the key when i turned it. not sure if the starter is heat soaked or what, cause i could still get it to crank over by crossing the terminals on the starter with a big screwdriver. i even got it to run a few times that way by having the key in the on position and crossing the terminals. when the car would die, i got a crazy clicking noise out of one of the relays on the driver's side firewall...not sure what that's doing yet.

 

First off, unplug the ECM, wait about 2 minutes, then plug it back in. Now drive around for a while. See if you get code 42 or code 13 again. Code 42 can be set by simply unplugging the set timing connector and stays stored in the ECM for an eternity. Code 13 is set when the oxygen sensor does not produce a useable signal after a resonable time period has passed. Common problems are either with the sensor, the wiring, or even running too lean. A bad MAF can cause problems with both the fueling and the timing. Those old analog bosch mafs have caused countless headaches with early TPI owners. You might let the engine idle and tap the MAF lightly with a screwdriver. If the engine stumbles, hesitates, spits, or stalls, the MAF is bad. You can also unplug the MAF and take the car for a drive. If the MAF is bad or going out, the car will run much better in "LIMP" mode without the MAF being in the system.

 

i did notice something interesting tonight. i was told to unplug the battery for 20 minutes to reset the ecm, i thought that simply pulling the fuse for 30seconds would be fine. so when i cruised up to Summit, i pulled the ground wire and let it sit for 3 hours. came back, started back up, still sputting and surging, but no longer throwing a code...that's kinda cool i suppose, lol!

interesting that you say that about disconnecting the set timing wire, cause i definitly did that to set timing a couple of days ago.

 

How does she run with the EST dissconected?

My friend had a similart problem, and he replaced everything, checked all the wires and repaired anything suspicious. Than he enede up replacing the distributor and it worked.

Now, we went to the JY and he was looking at the electronic spark controle module. Its located close to the relays on the firewall. Its a square piece with 4 wires going to it. These could make the EST not function correctly.

 

on the driver's side? i found a little square thing on the firewall with four wires going to it on the driver's side that was disconnected. i reconnected it, but couldn't tell you if that started the problem or not. it's been going on for a few days now and i can't remember when i hooked that thing back up, lol!

 

lowered fuel pressure back down to 35psi at idle and the driveability is better, but still not where it needs to be.

 

I'm having similar troubles with my '89 IROC 305 TPI, manual tranny. I've replaced the fuel filter, replaced the distributor assembly and the ECM. I even replaced the MAF sensor, but that did no good. The ECM helped the injector flow a little bit, but the flow is still weak and causes my car to stall once it gets warmed up to about 170 degrees or so. someone please help!!

 

ok, i'm hearing something about the importance of a heated o2 sensor when using headers over stock manifolds

 

33psi at idle and 42 psi with vacuum disconnected is correct.
If you're running headers and the O2 sensor is too far away from the exhaust ports to reach and stay at the proper temp, you may need a three wire heated O2 sensor.

 

ok, i'm running a set of hedman shortie headers, with the o2 in the collector on the driver's side. the guy that told me about it was running a set of slp's, who also got the same surging/bucking/sputtering problem that i am having. what will i need to do in order to make one of these 3 wire o2 sensors work and does anyone have a part number one an o2 sensor that would work well. i have access to bosch stuff a work, is that any good?

 

Check and see if the car is going in and out of closed loop before you put in a heated o2 sensor.

You will have to use a scanner and watch for the open loop or closed loop screen, or flag if you have a laptop.

My SLP 1 3/4 shorty headers didn't need a heated o2. My longtubes did though, so I don't think your shorty headers are the problem. The shorty's still have the 02 sensor close enough to the exhaust port to keep the sensor hot.

Have you checked for vacuum leaks?

 

plenty of times. i was hoping you would chime in soon bj. i don't have a scanner, and i'm not really sure if anyone around here does. what kinda scanner do i need to get for it?

 

A bent paper clip. Take it and Jumper A-B in the ALDL connector. Start the car. The SES light will rapidly flash as the car warms up in open loop. As the car enters closed loop the light will stop rapidly flashing and slowly start cycling on and off (roughly 1x per second) Once closed loop has happened, if the light spends more time ON than OFF, the engine is running rich. If the light spends more time OFF than ON, the engine is running lean. SES on = Rich, SES off = Lean and it should cycle back and forth about 1x per second.

 

ok, what all is the VATS system tied into? i was trouble shooting the module yesterday when i went to the folks house and i found an interesting find.

-does the VATS give the ignition system a signal to fire? if so, if the module is freaking out, would it cut the ignition system off when cruising?

-an electro-magnet is all the VATS module is. when i took the cover off to look at the module, the little "relay" part was not making contact. i pushed the contacts together and got the fuel pump and starter back, but could feel the electro-magnet trying to push it away kinda in a pulsing manner.

-i decided to by-pass the module with a paper clip. all you have to do is ground one wire with another. i've bypasses them this way in many cars and have found it to work great with no repercussions. however, in this case the paperclip started to actually smoke! never have i ever had this happen. i grabbed the module out of a parts car i have and the car turned over with no problems whatsoever, for about 5 seconds. it then started flipping out like the previous module, clicking on and off till it finally didn't work anymore. i think i've got another problem somewhere else now, independant from the module, but obviously effecting it. i started looking for grounds under the dash and nothing seemed out of place, other than a larger guage yellow wire that is under the steering column. it's in a big bundle of other wires. it appears that it had been cut, then someone twisted another piece of wire together to hook it back up. the contacts of the wire were brittle and obviously burnt. probably due to a lack of consistant contact (ie, no buttconnector, just twisted together) not sure what this wire does, but when it was disconnected i got a dead key.

i talked with a local mechanic and he told me to insure i had a good ground from the battery to the block and from the block to the car. i remembered shortly thereafter that my ground strap going from the block to the firewall was not hooked to the block, but rather to the bracket that my coil is mounted on. i kept it there when i put in my new accel supercoil, only because it was working and not giving me any fits. i'm wondering if i messed up any good contact that the ground strap did have when i put on the new coil. i'll be reconnecting it to the passenger side cylinder head when i go down there again. could this lack of good ground give me the problem from the VATS module that i'm encountering?

when the key is turned on, there is power to the coil, but even with the VATS bypassed, and fuel pump and starter signals are working, i've got no spark coming out of the distributor. it's got a BRAND NEW cap/rotor/distributor/wires/plugs/accel super coil. so if something is fried in one of those, i'm gonna be kinda upset.

once i get this car running correctly again, the 9" from my dad's 85 z will find it's way into my 90 and this 89 will go to my father. so it's kinda important to me that i get it running correctly, and in a timely manner, lol!

 

hooked up a new ground from the cylinder head to the firewall and no change. is there a relay somewhere that tells the VATS what to do? i've found little to no info on the internet pertaining to the Vehicle Anti-Theft System...probably how gm wanted it, lol!

if anyone has a wiring diagram of the VATS, that'd be awesome