couple questions. i have a 83 scrambler (I know its not an f-body, sorry guys) with a 305 TPI. I was wondering if anyone could tell me the best way to identify the year of the engine. I am running into issues where one cylinder doesn't work at all, and it idles very roughly. after it warms up, if you shut the motor off it is very unlikely it will start again for a few hours. i am thinking injection control? if anyone has any bright idea's i would love to hear from you. Thanks all

 

no start after warm: might be the senser on the front of the intake, (thats what mine was)

cyl. not fireing: look into those injectors.

what year: I dont know (but would like to)

 

pretty sure the number 5 injector is shot. pullin that out soon to check it out. also i am wondering about all the connections under the plenum, especially the one that controls injectors during cranking.

 

I think that the control module in the dis. takes care of the injectors when cranking (help me out if I am wrong guys)

there is only one senser under the air box (air temp. senser)

do a serch for checking the injectors (alot of info at thirdgen)

 

one other question joe. and it shows i am novice with the 305 tpi. what is that sensor? i am holding off on buying a camaro book until i know what year the motor is.

or maybe anyone else out there can refer me to a good guide book for the 305 tpi??

 

coolant temperature sensor.

check out TPIparts.net...they have all the sensors (and other things) needed for the tune ports (also, good place to do business)

 

The model year of the TPI makes little difference, especially in a retrofit. Even if the TPI is a MAF, or older digital MAF system, the ECM and program are what matters. My '86 runs with a MAF, but doesn't need the cold start injector and control. If you have a MAF sensor, it's from 1985-89. If the ECM is a 1227165, it's from a 1986-89. The rest doesn't matter much until we know how it is programmed.

 

Well, it seems through the use of a new coil (wired properly, unlike what the previous owner left me) and a few bottles of injector cleaner, it runs better. but on the otherhand it still occasionally runs like crap, check engine light and all. At least it almost always starts without starting fluid. I have it pretty much boiled down to flooding. now to figure out if it is a control issue, maybe the pulse width for the injectors is too long, or who knows. i'll let you guys know when maybe i come up with some more

 

Code scanning,

i bought a code scanner and came up with these codes. there are 4 different codes, but i think they all originate from a single issue. any help identifying the issue??

code 21 - TPS sensor voltage to high

code 22 - TPS sensor voltage too low /or/ fuel cutoff relay circuit open or short

code 33 - MAF signal voltage or frequency is high during idle /or/ MAP same issue

code 45 - Rich exhaust indicated

if anyone knows the common link you freakin rock. people have told me the sensor on the front of the plenum....temp sens. i believe, but looking to the more knowledgable crowd first. thanks

 

ok. so i guess i was jumping the gun a bit. i pulled out the multi-meter and tested the TPS and it was way wrong. i adjusted it and it helped a lot. Now maybe someone can clarify this one. the MAP sensor hose comes off the end of the plenum, and goes into the sensor, which the previous owner saw fit to just let lay under the plenum. i have read a bunch about the position (high.low, right side up and all) is this highly important? i am wondering due to having to take the whole plenum and stuff off to get it out from there and reposition it. anybody have the "prime" spot they think i should re-locate it too?

erik

 

The ECM uses the engine RPM and throttle position to calculate the correct intake air. Simply adjusting the TPS properly may have solved the problem. Clear the error codes and see if they recur.

 

Thanks vader, do you have any guidance on my whole MAP sensor question? i really think i need to take the plenum off and move the sensor, but i dont know where to or if this is actually necessary?

 

The position and orientation of the MAP is not important, but while being under the plenum might not be bad, it can't be good. You can mounti it to the firewall, or wherever the wire harness will reach. If you clear the ECM and run it, however, you may find that you don't have a MAP problem.

 

thank you. i had cleared the codes after TPS adjustment. the map doesn't come back on anymore. i know i had read somewhere that MAP sensor could be susceptible to gas build up and whatnot if it was lowered, as well as not being right side up and all. something about the membrane, etc. maybe thats not so much important

 

ok...for anyone that cares my TPS was intermittetently faulty. i got a new one and so far it runs like a champ. no highway time or anything yet, but i've got a good feeling anyways.. that should count for something. made the code 33 dissapear anyways. i pose a question though

I have a 7730 ecm, which indicates 90-92 (AXXB), but i am using a 85-89 TPS, which i have heard is different in voltage polarity or something. does anybody have an idea if i have maybe the wrong PROM in this vehicle i bought or just the TPS is interchangeable. according to the PROM i have a LB9 (305 TPI/ 700R4) ehich i know to be correct..any ideas?????????

 

The '90-92 TPI used a fixed (non-adjustable) TPS. The early TPI used an adjustable TPS. The later style ECM doesn't require a specific TPS voltage, since it will check the TPS voltage at startup to determine the closed throttle position. You can set the TPS at 0.50-0.60V and forget about it.

The fact that it was failing intermittenly, however, was likely the source of your problems.