After driving for about ten minutes or so, when i let off the gas it will idle at about 2000 rpm and when you give it gas it will die and wont start back up, until about two hours(flooded)and you can smell gas. i have new plugs, wires, cap, rotor, coil,distributer, icm, iac valve, fuel pump and fuel pressure regulator. any Suggestions?

 

Im only 15 but it is just an idea mabey your throttle linkages are messed up?

 

well, it would die when you pushed on the gas if it was that, something is making it run rich, i was thinking bad fuel injectors or tps sensor.I read that the risistance of the fuel injectors is sapposed to be between 1.16 to 1.36 ohms so i measured the resistance and they read 1.6 ohms. so i quess ill start there, i called autozone and they want $100 a piece which is outragous( )

 

migman

1) Check your fuel pressure - stock TBI system likes about 13 psi. Stock TBI fuel injectors can handle much higher fuel pressures without any problems (20 to 30 psi). Do you really have fire breathing 383??

2) After running engine, shut-off - check and see if one of injectors is leaking. Cracked fuel injector pods are very common due to over torqued fuel line adaptors.

3) At idle TPS voltage Pin B of TPS sensor should read about 0.5 to 0.6 volts. TPS voltage should increase with more throttle.

I hope this helps - let us know
//RF

 

change plugs and coolant temp sensor if its ur tps all u have to do is loosen bolts holdin it and adjust but i had this pro try starting it with the pedal to the floor make sure its too the floor this will tell the computer to stop dumping fuel.if its starts change coolant temp sensor
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and since u have tbi i do take air cleaner off and air cleaner spacer off and turn it over if its not pulseing fuel into the tbi its flooding and is coolant temp.

 

yeah take a look at my garage if you wanna know more about my 383 (89 camaro). the vehicle with the tbi problem is my 88 chevy 3500, wish it was as easy to figure out the problem with it as it would be with my 383 (carbureted)

 

i unplugged my tps the other day with it running, and when i gave it gas, it bogged, is that what you mean? or would i have to completley take it off?

 

un plugg ur coolant temp sensor in front of the intake theres a brass plug with 2 wires plug into it unplugg it and start it if ur flooded them plugs are done
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take a pix of ur intake put on here ile show u

 

oh, ok, yeah my coolant sensor on the front of the manifold is broken in half where it plugs in , but i didnt know it would cause all of that, but it does make sense. i was going to buy a new one a few days ago, but the idiot at autozone was talking to me about it and said dont even bother it would effect anything, they never know anything though so dont know why i listened to them about that.i will get a new one in the morning and tell you how it goes.

 

I was reading over what i typed it sounds kinda sarcastic, didnt mean for it to. it has takin me a year to get the 383 together, takes a lot of money, guess my ol lady and my car have a lot in common . but seriously it was sapposed to be a stock engine rebuild, got a little carried away, but it was worth it.

 

well were in the same boat 383 except i planned to get 450hp wich ive done havent got it in car yet but now iam thinking twin turbo on top of that.no prob man its kool.alote of peps think since iam new i dono nothing but iam 18 and done built at least 6 motors all high end i built my own rearend set posi up gears redone trany my last job i got the shop foreman fired cause he was sopposed to be a master installer and twic the age and i new just as much if not more if u got any tbi prob just ask.o and the reason why i sayed cts is because when mine and my bros went up it didnt flood.a year later car started smokin shutt off and wouldnt start back up.so i put code reader down and put pedal to floor and it started fouled all plugs i was happy

 

i've mostly stuck to carbureted engines most of my life but i have had a few fuel injected motors one of which is a ton truck that i go about five years ago with tbi and i have learned alot about tbi since but not nearly enough, so i figured i would keep the tbi instead of switching to a carb, figured i might learn something.i have had more problems from fuel injection, but its a vehicle, gonna have problems any way you go.

 

yea my brother likes carb plus he has a 454 bb 10mpg.carb is simple less head ache plus a tbi motor can mess up so bad u think its blown up.but ive many probs from it to mostly sensors

 

well, ive just installed a cts and a tps, getting ready to go for a test drive, hope i dont break down again. ill tell you how it turns out.

 

hope not hate seeing camaros on side of the road

 

well i drove it but not probably not long enough for it to start doin that, brought it back hope cause it idles kinda funny and is slugish, usually if i resest the computer it will act fine for a while and then start doin it again.
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after i installed the parts today, i didnt reset the computer, should i?

 

Yes, disconnect battery for about 30 seconds to clear all codes and BLM's

//RF

 

ur service engine light work? put a code reader on it and check codes

 

service engine light works, it went off after replacing cts and tps. i took out my spark plugs to make sure they werent fouled, while i was already working on it, left the number one plug wire off, didnt relize it and started it, and was running funny and i could hear a poping sound so i shut it down, and checked under the hood and saw that i left the plug wire off so i put it back on and restarted and it was idling funny. it idles between 800 and 1000 eratically. any thoughts? ignition control module maybe?

 

is any of ur plugs fouled check all of them when mine did this i replaced the plugs twice.cts dumped fuel at start up like crazy and fouled all plugs changed one at a time runnin better each plug.and check over all ur sensors like map sensor

 

yeah, i checked all of the plugs after i drove it, they are fine, but i left off one of the wires on accident and started it and the wire was sparking and the block, i didnt know if it would have messed up the icm.

can i check the map sensor without a scantool?
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does the wires leading to the deverter valve that is on your air pump set off and codes if you unplug it or do the wires just open and close the valve?

 

You can check MAP sensor with DVM while a vacuum gauge is connected with T to the same vacuum line. You can back probe MAP connector at Pin B, Circuit 432, Light Green/black with a DVM and measure DC voltage. If your engine is idling at about 18 in-Hg (~39kPa) Map sensor should have about 1.6 Vdc output. See Table below:
kPa|----| in-Hg |----| VacVmap
100 |----| 0.0 |----| 4.90
95 |----| -1.5 |----| 4.62
90 |----| -3.0 |----| 4.35
85 |----| -4.4 |----| 4.08
80 |----| -5.9 |----| 3.80
75 |----| -7.4 |----| 3.53
70 |----| -8.9 |----| 3.26
65 |----| -10.3 |----| 2.98
60 |----| -11.8 |----| 2.71
55 |----| -13.3 |----| 2.44
50 |----| -14.8 |----| 2.16
45 |----| -16.2 |----| 1.89
40 |----| -17.7 |----| 1.62
35 |----| -19.2 |----| 1.34
30 |----| -20.7 |----| 1.07
25 |----| -22.1 |----| 0.80
20 |----| -23.6 |----| 0.52


I hope this helps...

//RF

 

thanks for the chart that will denfinetly help.

 

while on lunch today i stopped by taco bell, and was wainting in line and my truck was idiling, all of a sudden it just shut down, 3/4 tank of gas, so opened hood, figured it was electrical so i got out my dvm from tool box, started searching for the problem, put a piece of a rag under the injectors and crank the motor over, no gas, so i tested the resistance of injectors and power to them, risistance was good, but no power, then it struck me, check the fuses, pull fuse cover off and pull ecm fuse and sure enough it was blown. all while sitting at the drive thru, people were pissed, i was pulled forward just far enough so they couldent go around and get to the speaker . anyways check simple obvious things first

 

migman

Now comes the hard part - figuring why ECM fuse was blown.

 

yeah, thats what i was wondering at first but i looked at what fuse was sapposed to be used (10a) and it only had a five amp fuse in it so i put a 10 in it, drove it about 60 miles since hasnt blown yet so i hope it was just the fuse.

 

migman

So, after replacing CTS and TPS you got your truck running OK?? Just want to make sure that you got your problem resolved.

//RF

 

STILL IDLES FUNNY, FROM 800 TO 900 BACK AND FORTH LIKE A STROBE.

 

Hmmmm

I do not like unresolved idle issues.

How good is your TB body to intake manifold gasket?
What about IAC gasket??? Did you reset (forced it into park position - see sticky) IAC after installing a new one??
Take a look to a fuel spray coming out of each injector. Both injectors should produce nice even spay cone of fuel hitting TB bores. Use timing light to see the light show.
O2 Sensor - what shape is it in??

//RF

 

yeah problems with idle or really any engine problem for that matter isnt good, every time im sittin at a red light with it idling it bugs the heck outa me. IAC gasket is new, for seating the iac the instructions with it just said to measure the pintle and make sure that it extends no more than 1 1/8 and then install and drive at about 2500 rpm and it will seat itself, what sticky were you refering to? guess i could replace the intake gasket and see if that helps. how would you tell if the O2 was bad other than trouble code? the fuel coming from the injectors looks like a perfect cone to me, although the hanes manual, i have says that the risistance of the injectors is sapposed to be 1.16 -1.36 mine read 1.6 ohms.

 

oh, when i start it in the mornings it idles at 1500, normal? it didnt used to do that unless it was really cold outside.

 

migman

1) I can not comment on the injector coil resistance. When measuring very low resistance loads DVM test leads and contact resistance may alter actual readings. They are in the ballpark

2) IAC and TPS adjustment routine can be found here:

https://www.thirdgen.org/tpimod2

3) During very cold start it is possible for 1500 rpm flare up - it is dependent on ECM calibration, however it should come down quickly to about 1000-1100 RPM. With a functionning thermostat engine should be near normal operating temperature (75 to 80C) in about 3 minutes. Higher cold RPMs maybe indicative of a vacuum leak.

4)To really figure out what a heck is going on get a lappy with WinALDL and ALDL cable and data logging to see ECM engine sensor data. It is a gateway to another world - no pun intended.
//RF

 

ok well is ur service engine light on start ur car and loosen bolts on the tps and adjust until it evens out?

 

check engine light isnt on anymore, i have been driving it and it seems to be fine except for the idle is a little off, i loosened the bolts on the tps and it is non adjustable, on the sticky thread it says to take the metal cover off of the idle screw but i cannot find a metal cap.

 

Migman

Your TPS sensor does not require adjustment. ECM has self calibration routine which automatically determines that throttle is at 0%. This is true as long as TPS sensor provides 0.20 to 0.90 Volts at idle. A typical TPS will have 0.50 to 0.60Vdc at idle. As long as your TPS in the above mentioned range ECM will be able to compensate - hence no mechanical adjustment.

//RF

 

oh, ok i was confused someone said to loosen the screws and adjust it. and yeah it reads 0.557 at idle.

 

Yes, the other poster is also correct, but (there is always a but) the later car ECMs had idle auto zero routine built in. These use non slotted TPS sensors. Looks like you are right in middle of the range - 0.557Vdc.

//RF