Hi im Gary, i just bought a 86 trans am with a swapped 350 tpi in it. im in the process of selling the motor for a future engine to take its place. the engine has some trouble firing. it cranks over, new alternator and the starter is fine. some days it will fire the second time i crank it over, some days 5 times, other days it takes ether to get it to start. now it wont fire at all. this is a prob considering i have to sell the engine soon. i noticed that there is a maf sensor on the intake, that didnt come stock so could that be the prob? wat else should i check for? i also just did plugs and wires. Any input would help.

Thanks, Gary

 

also i know im getting plenty of fuel cause i can smell it when i crank it over more than twice. please help

 

MAF was stock for 86 but what year did the motor come from? Did you reuse the stock 86 wiring? Was it a TPI car originally or did you use a 350 TPI wiring harness from the motor you got?

 

well the guy i bought it from told me it was a 350 79 vette block and it was converted to tpi harness and most components. and the wiring looks like he did the swap over night. all the emissions are deleted as well and im getting a service engine soon light. ill try to run a scan tool on it but im not home and wanna try to figure it out before i get home for spring break.

 

its weird my bro drove it the other day, it was sitting for bout a week and he said it started up the second time he cranked it over he got 93 gas went to friends and went about his normal biz etc etc and then the next day tried cranking it over and over, tried ether and no firing but it was cranking strong.

 

Anything done to the engine? heads/cam?

More than likely its a stock ecm/chip and trying to run a motor with a different cam setup and not liking it at all.

What is the part number on the ecm being used? Also can you open it up and look to see what chip code is on it? Should have a 4 letter code. Should have a number on it. Since you say its has a MAF its probably a MAF based ecm Just need to determine if its a stock chip, either 350 chip or 305 chip and from there determine what is done to the motor.

If the motor is much different than a L98 TPI motor, and the chip is stock 350 TPI chip, then it probably wont run well and just need tuned. Hence the rough running/starting.

SES light is on because if its a stock chip its looking for emissions stuff and when it doesnt see those items, it will throw a code.


Also has VATS been eliminated? Could also explain why its not starting. Does it get spark when trying to fire? Lots of these cars had VATS and requires a special key. If not it wont start. That needs to be disabled in the chip.

 

It cant be VATS cause i was running the car for like a month before this started happening and wouldnt it always not start is the system was disabled? nothing has been done to the motor and idk bout the ecm cause im not home.

 

Well if it ran for a month before all this started happening I would look at the MAF as being faulty or some other issue like bad injectors..

Ohm the injectors after running the motor to warm everything up. I believe they should read near 14-16 ohms when warm? Have to check the tech article to make sure. If they dont, then they are bad and could be causing your problems.

If you can check the SES codes it may say MAF sensor is malfunctioning. If you can get access to another MAF, try it and see if the car runs. I'd hate to tell you to buy a new one if its not the problem since they are pricey.

 

ya i know im not trying to buy a new sensor there out of my price range for selling the motor for $400. when i get home ill check the ohms on the injectors and eliminate the possible prob of spark and test for that as well. ill pm you the code for the ecm cause i have no idea bought that kinda stuff. im just started learning bout it at my college