i just rebuilt my 305 tpi motor in a 1991 camaro z28 convertibe

i put on:

summit racing vortec heads
comp cam
edelbrock vortec tpi intake manifold
hooker 2055 exhaust
flat top pistons
bbk adjustable fuel regulator
complete rebuild
and all new sensors

now it started first try when i built it .. and i played with the timing and fuel pressure .. ended up with 10* btdc / 46 psi

it ran fine yesterday .. just needed a little more fuel i think ..

but i started it today and drove it out of the garage and it sounded good .. but right as i got out the motor stumbled and died ..

have no clue why it did this .. but ive been playing with the timing all day and it wont start unless its soo advanced i cant see the marker with the timing light .. and even then its not running on all cylinders ..

it keeps flooding .. and it will run one second .. and then wont the next

i checked the codes and its throwing a "43" code .. which has something to do with the computer controlled timing .. which would make sense ..

also .. when i got it started again .. it was throwing out white / grey smoke (its 40 degrees here) .. and some fluid was spitting out of the tail pipe .. might of been excess fuel from trying to start it all morning ..

can someone please help ..

only thing i could think of is my computer is fried?

(before the rebuild the motor "hung" at a high idle before returning, and the chevy dealer said it might be a faulty computer)

but ive replaced all the sensors / distributor / etc

 

to clear a flood with tpi press throttle down to wide open throttle
and try to start it its called clear flood mode
being that its 40 outside the smoke may have nothing to do with anything

43 is for Knock sensor it is retarding timing as it is sees engine knock
gear drive timing chain by any chance? even silent ones throw out code 43
or it could be the knock sensor is unplugged i had a starting issue with mine when i forgot to put the tpi knock in

did you make sure to set timing with the EST wire unplugged ?
did you make sure the that your not a tooth off ?
i know you wont fire on all 8 if its a tooth off and would have to be very far advanced to start
im just throwing out ideas
with efi its always something simple that seems to be the problem just seems like your haveing more then 1 issuse

 

yea .. i cleared the flooding by unplugging the injectors and turning it over a few times ..

i found that the "43" is for tps sensor, knock sensor, or ecm wiring

i got a new tps and new knock sensor .. and i checked all the wiring and grounds ..

and i have had the engine running for a few days just fine .. i started it this morning and backed it out of the garage and then it just quit on me ..

found out it trys to start around TDC .. and almost runs when i advance it a ton ..

i highly doubt a double roller timing chain would jump a link .. or could it? .. hell i hope not ..

the only thing i can come down to is a f'd up computer ...

i remeber a dealer mechanic saying my previous idle "hang" was because of a failing computer ..

any other ideas .. or am i on the right track by thinking the computer has given up ..

the 43 means that the computers "electronic timing system" has failed .. and ive allready checked everything and all the grounds ..

seems strange why it will run for almost a week and all of a sudden die ..

thanks for the help..

adrian

 

43 is only knock sensor part of the est on these i looked it up the 1991 camaro service manual
41 is failed mem cal basicly failled ecm really
or cylinder select error

42 is Est failure and that could mean faulty ecm because the est chip is in the ecm on 90-92s
also be bad ignition module

are you doing the count the blinking light for checking codes or do you have a scanner really 42 sounds more like your problem and its possible if you misscounted the blinks

do me a favor and recheck the codes atlest if your counting the flashes of the ses light if so your most likely correct with haveing the ecm going out

as for it working fine for days then just stopping working

intermittents are caused but faulyy electrical connections or wiring
somes a code will not always be saved with intermittents

make sure the est/knock sensor wires are routed away from the spark plugs
there is a lot more listed mainly its just differant sensors that effect starting recheck your codes to verify id hate to see you have to buy a new ecm if that isnt the problem
you check your fuel pressure by any chance?

if you have a doubler roller its not going to effect the knock and i dont think it would jump time unless its falling apart
but then again i did break 2 timing chains on my v6 car doing exactly what your doing now
each one i always thought naw not the chain and went through and figured it must be est

 

i checked the wiring to the knock sensor and it all looks good ..

its a brand new knock sensor .. only think is i need to check if it is the right one .. did some research last night and found there's two different types that look alike ..

but as for the codes ..

i did the flash codes thing ... and it came up with "12" three times .. then "43" three times ..

but i could swear that it came up like this sometimes "43" "42" "43" .. instead of "43" "43" "43" .. but i could of mis counted ... even though i did it about 10 times ..

i went out last night and bought a new ecm .. it was only $60 ... and im pretty sure that was causing my "idle hang" before i did the rebuild .. the dealer said he has seen some ecm's go faulty b/c these were some of the first to be made / developed .. and arent the best ..

ill let you know if it was the ecm when i get it in later today ..

i got the ignition module checked ... and it works perfectly / is brand new with the distributor ..

thanks again,

adrian

 

if it works then we know it was a code 42 lol

 

Have you checked your alternator? My car threw a code 43 a while ago and the car stopped working. I did some searching on here, saw it could possibly be the alternator and replaced mine. Problem solved. So... if it were me, I'd at least go to the local parts store and get the free test done before throwing more money at it.

 

thats odd but hey an alt being low on output dose do some crazy things

 

ok i swapped the ecm ..

i dont get code 43 (or 42)

but .. it still doesnt run .. i cant even get it to start with some throttle on ..

but now its throwing a 15 code .. (but i did take the coolant sensor connecter off to see if it would start) .. so that might of just been that..

im gonna go grab a multi meter and check all the sensors and connecters


do yall think it could be the timing chain .. then again .. the distributor still pointed to #1 when i took the cap off .. and it was at TDC

before it died .. the nut came off the alternator wire to the battery .. and it sparked a couple times .. i wonder if that killed it ..

i'll take it off and go get it tested .. just to make sure ..

i did another fuel pressure test .. and it went straight to 46 each time i released the pressure and turned the key .. and when i TRY to start it .. the needle waves around from about 40 to 46 .. guessing that is the injectors opening .. but i did notice that with the key on it went to 46 .. then went slowly down to 40 ..

all the injectors ohm at around 16.3 .. so im assuming there allright ..

how fast would the pressure drop if they were leaking .. and would this cause it not to start / run extremely rich .. b/c it took a couple minutes to drop

thanks .. adrian

 

fuel pressure seems normal

start the car with the distributor cap off make sure the chain didnt snap it can happen since you can start it sometimes this is a very unlikely case
got any major vacuum leaks? that would make it need more timeing to start

try 3/4 throttle when starting for ***** and giggles it should be able to catch
is your min idle correct what voltage is the tps showing with the key on but not running
is the iac working? hooked up
im just tossing out ideas at this point for you
as i know how crappy i feel when a car wont start no matter what i do

have you made sure your getting spark to all 8 plugs? is one or more plugs fouled
if you have been running crappy maybe that is the case
did you make sure you got the correct ecm prom ? or did you just use your old one? sometimes just the chip is shot

also make sure your battery is fully charged ive had isses with a few tpi engines that wouldnt start because the injectors didnt have the juice to pluse

i mean your just haveing more then 1 single issue

we know your getting air he have to assume by the pressure that your getting fuel
so its got to be spark or the timeing at when its produced

you are unpluging the brown EST connector before setting timeing correct? im assumeing you are

is your egr stuck open ?

when it is running what is the idle like? low high? rpm range when it dose run dose it run good or dose it seem like something is off still?

when you put the cam in did you set it to the correct degrees?

since when your setting timing you have to go past 12* something is wrong there even with your mods 0-6 * should let it start
ten tells me your a tooth off
sorry if you end up thinking im second guessing you or giveing you dumb ideas im just throwing out mistakes that i have made
but is the plug wireing correct
how about plug gap for the vortec heads im assumeing there the 350 versions
where is your compression ratio ?

 

ive tried all throttle / timing settings to try and start .. nothing .. just a few cylinders fire hit / miss ..

the plugs constantly are getting fouled .. so i think im not getting spark for some unknown reason ..

my battery was fully charged this morning .. but now its charging again ...

can the prom be fried? .. it seems weird why it would run perfectly .. then suddenly die and not start again ..

i think it has to do with the computer controlling the timing b/c it ISNT right now at all ..

im going to get the alternator tested, let the battery charge, and buy a multimeter .. and maybe an auto xray if i can find one cheap enough at the auto parts store ..

ill keep yall updated .. thanks for all the help .. ive never had this much trouble with this car .. its been good to me till now .. lol .. drove about 100 miles on a blown headgasket just fine / half the sensors broken off .. but when its completely rebuilt .. all new sensors, etc .. it DOESNT RUN ... aaaahhhhhhh ..

lol ..

 

While trying to start it pull the vacuum hose off the fuel pressure regulator. Could be a blown diaphram if it wasnt replaced when the adjustable one was put in. Will cause gas to shoot out of the pressure regulator if it is shot..... and will obviously cause flooding.

 

my girlfreind just happen to toss me an idea
did you happen to make sure there was room with flat tops?
i know the stock 305s have valve reliefs in the pistons as they meet the block deck ive never put 350 heads on a 305 so but my girlfreinds father did and smashed the valves and damaged the pistons ran ok at first she said but after the first 100 miles it wouldnt run well then finaly he started hearing noise in the exhuast
just her 2 cents

i still think its timing related or ya check the diaphram on the fpr you never know

 

that is a good point with the fuel regulator ..

as for the egr .. its blocked off .. got the edelbrock tpi hi flow base w/ vortec heads ..

i fixed the 15 code .. had to clean the connector for the temp sensor ..

but the 43 code has come back ..

so i got a multimeter and checked the knock sensor ..

i got a 4.94 volts to the knock sensor .. so im assuming that the wire between the sensor and computer are fine ..

then i ohm'd the sensor to a ground .. and on a 200k setting (??) .. it read 99.8

is this the correct sensor .. or i wonder if its not getting a ground threw the block .. i think i put thread sealer on everything ..

im gonna do some research again .. saw something last night about there is two different knock sensors ..

should it start with the fuel vacuum disconected .. or atleast try ..

thanks ..

adrian

 

disconnect the knock sensor then try and start
its not going to hurt it with it unplugged
unless the engine is really knocking
unplug the afr aswell but make sure the plug the vac line with your finger or something
if

 

ok .. figured out that the new knock sensor i had in there was the wrong one ...

so i put the old one back in ... and the code went away ..


but now it wont start or stumble at all .. for some reason i have no spark ..

checked the plugs and there not smothered in fuel like before ..

any ideas why it wont start .. or why im not getting any spark ..

thanks ..

adrian

EDIT: ive been trying to start it all day and the battery is low again, and there might be a bunch of unburnt fuel on the o2 sensor .. would this cause it not to start ..

 

low bat could cause injectors not to pluse and low spark output

charge up tha battery and recheck the distributor just make sure its 1 is lined up with tdc

you should be able to start it on 0 with the est wire unplugged

now that you know the code 43 issue
we can assume you are getting no codes at all so now we are just dealing with timing low bat voltage

i think if you charge it up it should start for you with out issue but if not thats when you need to assume its timing

my idea is that since the knock was wrong it was detecting knock when there was none causeing you to advance it more and more to make up for the ecm retarding it so now with the correct knock you "should only need to make sure that your set for 0 or 6 to start it then adjust for performance from there

if it dosnt start then let me know had some crappy weather so been at the pc most the day

 

yea ..the battery is extremely low ..

it turned over like normal / a little slow .. and fired a little at first .. but then didnt fire at all ..

i made sure i was at 6 .. but tommorow .. im gonna set it again just to make sure ..

im hoping it starts right up tommorow once the battery is charged and the fuel dries up on the plugs

ill let yall know .. but i dont thing its flooding like it used to anymore ... just not firing ..

 

then at this point its only timing left to figure out im sure the low bat is causeing less fuel and less spark

hell if you had a car to use to try and jump it should fire up now

 

nah .. its dark .. and i got it on charge .. so ill just try it tommorow ..

 

just found something in another thread ..

someone else had the same starting problem

hit / miss / catch sometimes and the motor acting like it wants to start .. and good fuel pressure .. and good plugs, wires, coil, rotor, cap, etc ..

but the connectors on the coil are messed up .. so the computer doesnt know when to fire a spark or add fuel ..

its making sense to me now .. lets just hope im thinking correctly .. b/c im missing the "tabs" off the connectors on the coil ..

and my motor will try to start .. but wont hit on all cylinders ..

 

Hmmm, I remember with my GTA, I had a trouble like this... Everyone was saying it was the computer, and finally, do you know what it was? The MAF!

 

i can't believe no one threw out the idea of IGNITION CONTROL MODULE!!!!! take it out and have it tested. any parts store can test it. get a new one for 80 bucks or so. i bet it fires up then. keep us posted.

 

i did get it tested ..

i think i posted two of these threads up and someone said it on the other one ..

EVERYTHING on this motor is brand new .. all sensors, distributor, rotor, cap, plugs, wires, etc

I FINALY FOUND THE PROBLEM .. YAAAAAAAY !!!!

ok ..

so here it goes ..

i was backing out of the garage on saturday .. the motor cut off b/c the knock sensor was the wrong one and the motor was doing a force knock test .. and for some reason the plugs got all fouled up due to missfires / flooding ..

i didnt know this / even cleaned most of the plugs a couple times ..

now .. yesterday i fixed the knock sensor "43" code by putting the old one back in .. the multimeter said it worked fine ..

but it still wouldnt spark .. checked and reset the timing many times .. but still didnt start ..

so today i saw there was a huge gap between the rotor and the terminals on the distributor cap .. now i thought they were supposed to touch .. but i went to orielly's and compared it .. a new one made my MSD (thought it was supposed to be good) look like a piece of crap .. AFTER 3 MILES .. WTF .. the orielly guy couldnt believe it only had 3 miles on it..

so i bought a new one .. when i got it on .. still didnt start .. tryed to start a little better ..

but nothing .. so i had the grand idea of putting the original spark plugs in place of my $45 set of E3's .. i changed out 4 plugs ... and what do you know .. IT STARTS (well runs on 4 cyl. but you get the point)

so my conclusion is .. DONT BY MSD ROTOR / CAP KITS (the borg / warner ones look a whole lot more "heavy duty")

and even though E3 spark plugs are $8 a piece .. they dont work with vortec heads and get gummed up EXTREMELY EASY ..

im friggen glad i got this sorted out ..

so .. any suggestions on spark plugs .. i was looking at a set of the shorties b/c i got the hooker 2055 headers .. and the E3's BARELY fit ..

 

I like ACDelco cap, rotor, spark plugs and wires, never had a problem with them...

 

actually i think those are the plugs that were on the car ..

would the accel shortie plugs work allright .. or are there any "known problems" with them

i need the clearance between the spark plugs and the headers b/c a few are touching and i cant get them out without unbolting the headers .. and i really dont plan on having to take the headers off everytime the plugs happen to get dirty (incase they do again)

 

i told you check the heat range on the plugs hear i thought you had normal plugs i wish you would have said you where running differant ones
i knew the vortecs can be picky with plugs

 

i think vortecs use a specific style of plug... a certain reach length so you better make sure you get the right part number for that. else you wont get a good burn.

now when you get good plugs, redo your timing adjustments and fuel pressure

 

most guys dont think to get plugs for a vortec engine they get them for there stock engine not thinking about it
at lest from what ive seen from local people

 

i went and got accel shorties

but noticed that they are the same whether i look up the heads i got .. or plug in the original heads ..

in fact there shorter than the e3's but ill see how they go ..

what is the length i need .. i got .460 right now .. but do i need longer

i got summit racing vortec heads .. 170 cc .. 67 cc .. 1.94/1.5 valves ..


thanks .

 

AC delco R44LTS for vortecs, gapped at .045. that wil work

else go to the store and ask for plugs for a vortec truck from the mid 90's or w/e years had vortec heads stock. Make sure it says Long Thread for the vortecs. LTS is commonly used at the end of the part number to show its a long thread plug

 

naw .. i mean the reach ..

right now i got .460" reach on the accel shorty spark plugs ..

but do i need a longer reach .. such as .708" ..

SUM-151124 is the part # for my heads from summit ..

they have a ngk .460" reach spark plug on the "recommended" list for those heads ..

should they work allright .. the e3's were the same reach .. but i think all the extra "prongs / ground straps" got in the way of the spark .. and the plugs got fouled up


thanks,

adrian

 

i used stock tpi plugs. they were short. lesson learned. expensive doesn't mean it's better. i.e. you gotta pay to play=horse ****. glad you got it running. sometimes you just gotta take a day break with a beer and think about it .

 

lol .. if only i was 21 .. haha .. im 17

yea .. im friggen glad i figured it out too ... and thinkin to my self how i could of missed something soo darn simple ..

then again .. i did clean atleast 4 of them (all i can get to w/ the headers) .. and it still didnt start .. looked at them today and deep down in them there all gunked up and looks like they short out .. so oh well ..