Swaped a 350 TPI into a 305 TPI car!! Now it wont hold timing ETC...
Ok- i have got my engine in and all the tpi stuff hooked up,
itsa 358ci sb with vortec heads, 9.75:1 compression ratio, forged flat top pistons, forged rods, balacned rotating assembly, high flow baseplate& runners, Ported & polished plenum, stock TP 24# LT1 injectors. Shortty hedders 1 3/4 primarys 2.5" collectors.

ok- I have not had my Eprom reprogramed yet, so i was wondering if that might be ther problem right off the bat, but here is what happens.

The engine has to crank and crank and crank, probably added up to 3 mins of cranking. ( not strait cranking of course but about 7second intervals) and rotating the distributor

Finally she will start up but run like crap and then when it warms up it will idle on its own but at about 1300 rpm's and surge to 1500 rpms. Then it will settle down and idle at about 750 but then she will surge and die again.
Whats wrong there?

Also- My fan only turns on when engine starts, and shuts off when the engine dies, Isnt it supposed to turn on when it reaches a certain temperature, and the computer shut it off at a certain temperature? It would turn on around 180 or 185 before..

Thanks for all your help!!

Please move this post to the proper board if this is not it.
Thanks.

 

Did you time it with the ESC wire disconnected? If not, disconnect that tan wire and re-time it. Common mistake on these cars.

 

Where is this wire located???

Ive disconected the BAT wire to the distributor, brougth it up to TDC on compression and checked the rotor, but i dont know where the ESC wire is located..- is it in the 4wire connector that plugs to the harness?

 

it's a one wire connector usually by the master cylinder and brown in color. or some years it's by the A/C box on the other side. really easy to see, i'd disconnect that and set timing first and then reconnect it and it should run much better.

 

Ok- i'll check it tomorrow.. its ESC Electronic Spak Control im assuming??
Thanks

 

OK- I disconnected the brown one wire connector above the AC/Heater box on the passenger side of my car, Then I disconnected the distributor battery wire, put it back at TDC on compression, then reconnected both.
I fired it up- still didnt want to idle, and i still had to move the distributor to get it to rev ok. i had to hold my foot on the accelerater pedal about 1/4 of the way down and hold it above 750 rpms. About 20 sec later my hedders were glowing cherry red and it was popping and cracking like ****.

and i disconnected the knock sensor too.

I really didnt notice any difference between before i disconnectd the ESC wire and after besides my hedders glowing red.

Any other ideas besides i need to have the Eprom reprogramed?
Thanks

 

Ok- well- my assumption is that i did not disconnect and reconnect the wire in the right way.

I redisconnected it, started the car, adjusted the distributor to 0, let it idle on its own ( id did great - no poppin and crackin, no glowin hedders) then i reconnected the wire, and it stayed running!! and running smooth.
and every once in a while the computer would rev up the engine- i think its trying to compensate for the vaccum leak i havent found yet - might that be the cause for idling between 750 and 1300 rpm??

 

Thought all the TPI cars were 6 degree timing for setting?

Earlier 305's different?

Possible to bump it up to 8, I personally wouldnt go much more. Get windmill cranking on hot starts and they knock enough as is fro the factory. Wouldnt go too far without a scanner? got one?

later
Jeremy

 

Is this 6 deg. advanced or retarted?

Idleing it is about 0-2 deg to the left of the zero( if your looking from the front of the car to the back) i get the adv. and ret. confused so you can help me out there,

and you know i dont have a scanner yet jeremy..

Thanks

 

six degrees advanced would be 3 slots over from the zero slot towards the passenger fender.

 

Ok- so set it there w/ the timing light and leave it.

Now- the car idles but way to high- what causes that?

 

is the throttle body shut all the way? you'd really need a scanner hooked up to know for sure. could be improperly adjusted TPS voltage at idle. who knows without that scanner though.

 

The butterflys are shut all the way.

 

check TPS voltage to make sure it is within spec then.

 

OK- where do i hook my multimeter up to? and what should the spec voltage be?? - or will the manual tell me?

 

i'd ask on the TPI board honestly. i'm just telling you what little i know.

 

You really should get a scanner to check your iac settings and look at stuff like tps settings and function and checking that all sensors are operating. Takes all the guessing out of it!

 

Here is some info that may help....i got this for an 89 TPI 350, so if yours is different let me know and i will change/post up the correct stuff for ya tomorrow:

Initial Timing M.T. [1] 6°BTDC

Initial Timing A.T. [2] 6°BTDC

[1] Set timing at 400 rpm in Drive.
[2] Set timing at 450 rpm in Neutral.


Set timing under the following conditions:

Normal operating temperature
Air cleaner installed
A/C off
Transmission in neutral
Disconnect SET TIMING connector (tan/black wire) located in harness close to distributor. DO NOT disconnect 4 wire connector at distributor.
Connect timing light and adjust as necessary by loosening hold down bolt and rotating distributor. For specification, see ELECTRICAL AND ELECTRONIC SPECIFICATIONS in SPECIFICATIONS. Tighten hold down and recheck the timing. Stop the engine and connect SET TIMING connector. Clear ECM trouble code by disconnecting ECM power source.


Chart C-2C





Chart C-2C Wiring Diagram






CIRCUIT DESCRIPTION :

The ECM controls idle rpm with the IAC valve. To increase idle rpm, the ECM moves the IAC valve out, allowing more air to bypass the throttle plate. To decrease rpm, it moves the IAC valve in, reducing air flow bypassing the throttle plate. A "Scan" tool will read the ECM commands to the IAC valve in counts. The higher the counts, the more air allowed (higher idle). The lower the counts, the less air allowed (lower idle).

TEST DESCRIPTION : Numbers below refer to circled numbers on the diagnostic chart.



The IAC tester is used to extend and retract the IAC valve. Valve movement is verified by an engine speed change If no change in engine speed occurs, the valve can be retested when removed from the throttle body.
This step checks the quality of the IAC movement in step 1. Between 700 rpm and about 1500 rpm, the engine speed shpould change smoothly with each flash of the tester light ijn both extend and retract. If the IAC valve is retracted beyond the control range (about 1500 rpm), it may take many flashes in the extend position before the engine speed will begin to drop. This is normal on certain engines, fully extending IAC may cause engine stall. This may be normal. Steps 1 and 2 verify proper IAC valve operation while this step checks IAC circuits. Each lamp on the node lights should flash red and green while the IAC valve is cycled. While the sequence of color is not important if either light is "OFF" or does not flash red and green, check the circuits for faults begining with poor terminal contacts.
Steps 1 and 2 verify proper IAC valve operation while this step checks IAC circuits. Each lamp on the node light should flash red and green whilt he IAC is cycled. While the sequence of color is not important if either is off or does not flash red or green, check the circuits for faults.
DIAGNOSTIC AIDS :



A slow, unstable idle may be caused by a system problem that cannot be overcome by the IAC. Out of control range IAC "SCAN" tool counts will be above 60 if idle is to low, and zero counts if idle is to high. The following checks should be made to repair a non-IAC system problem.
Vacuum Leak (High Idle) - If idle is to high, stop the engine. Fully extend the IAC tester. Start engine. If idle speed is above 800 rpm , locate and correct vacuum leak including PCV system. Also check for binding of throttle blade or linkage.
System lean (High Air Fuel Ratio) - Idle speed may be too high or too low. Engine speed may vary up and down, disconnecting IAC does not help. May set Code 44. "Scan" and/or voltmeter will read an oxygen sensor output less than 300 mV (0.3volt). Check for low regulated fuel pressure or water in fuel. A lean exhaust, with an oxygen sensor output fixed above 800 mV (0.8 volt), will be a contaminated sensor, usually silicone. This may also set Code 45.
System rich (Low Air/Fuel Ratio) - Idle speed too low. "Scan" counts usually above 80. System obviously rich and may exhibit black smoke exhaust. "Scan" tool and/or voltmeter will read an oxygen sensor signal fixed above 800 mV (0.8 volt). Check for high fuel pressure or possibly an injector leaking or sticking.
Throttle Body - Remove IAC and inspect bore for foreign material or evidence of IAC pintle dragging the bore.
IAC Valve Electrical Connections - IAC Valve electrical connections should be checked for proper contact.
PCV Valve - An incorrect or faulty PCV valve may result in an incorrect idle speed.
Refer to TESTING PROCEDURES/DIAGNOSIS BY SYMPTOM/STALLS-ROUGH UNSTABLE OR INCORRECT IDLE. .

To reset the Idle Air Control (IAC) valve pintle position, proceed with the following:

Depress accelerator pedal slightly.
START and RUN engine for 5 seconds.
Turn ignition "OFF" for 10 seconds.
RESTART engine and check for proper idle operation.


Thats all i could find for ya, got it from Alldata at my college, if you need something more or if you need a different year let me know i will replace what i have up top for ya, good luck!!

 

see i don't have that kind of problems with my car..... who needs a computer :-D

 

I feel that carburators are for people who dont know what the hell they are doing.


UPDATE- Things are running good now- adjusted timing, adjusted TPS sensor, got tranny back, No more runing lean- it actually does what its supposed to, and idles at around 950 RPMs...

 

i'm sorry you feel like that... but i do know OBD I and OBD II systems as well with passing the ASE P2 test so i feel that i do know what i'm doing thank you come again :-D

 

I see, and im glad for you, but im just a senior in high school. So, i think im doing pretty good for myself.

 

yea your doing pretty good. i will admit that. i know fuel injection systems i just don't like them for racing now for a daily driver where i do care about fuel mileage... then yes i would take EFI car over a Carb car any day :-D

 

lol definately not the right approach there, but i guess everyone in the NHRA and nascar must be morons too. Carbs are the EASIEST way to get higher HP amounts out of combos for the cheapest. Didn't say a daily driver or better fuel economy, but there has yet to be a back to back test where under WOT a carb made less power than any Fuel Injection out there.