TPI Question
Thread Starter
Pro
Joined: Apr 2004
Posts: 687
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From: Atascadero Ca
TPI Question
I"m retrofitting a 78 with tuned port injection off of an 87 camaro, with mass air. The same injection the vette uses, i'm pretty sure. Anyway, the motor is chevy's 350cid crate motor, I've got the tpi all hooked up ready to go using the painless wiring harness. The car turns over, i'm getting pleanty of spark, getting pleantly of fuel to the rail, 45psi. The car cranks fine, and fires a few times, but just won't get going. It cranks and fires and spits a few times, but won't stay alive. I'm getting code 12 out of the computer, nothing else. Any ideas? Thanks, Mike
Burning Brakes
Joined: Aug 2000
Posts: 1,146
Likes: 2
From: Albuquerque NM
Re: TPI Question (i885744)
A couple of thing must be in place for the ecm to continue firing. First is the oil pressure...do you have an oil pressure sensor? Also the engine need to achieve a certain RPM, 400? Does your ECM know how fast the engine is going?
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: TPI Question (i885744)
Have you checked fuel rail pressure after it dies?
The fuel pump receives power through the FP relay for 2 sec. after your turn the key on but relys on the oil pressure switch atop the rear of the intake base after that. You can use a jumper to supply +12Vdc to the fuel pump to see if that's the problem.
Data from the MAF to the ECM is also necesary for the engine to run.
The fuel pump receives power through the FP relay for 2 sec. after your turn the key on but relys on the oil pressure switch atop the rear of the intake base after that. You can use a jumper to supply +12Vdc to the fuel pump to see if that's the problem.
Data from the MAF to the ECM is also necesary for the engine to run.
Thread Starter
Pro
Joined: Apr 2004
Posts: 687
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From: Atascadero Ca
Re: TPI Question (65Z01)
i've got the summit "oil pressure switch" threaded into the top of the block, right behind the intake manifold. A few weeks ago i got the car to fire up and run for a few minutes. Is there any way that i can bypass the oil pressure switch? Can i just jump the 2 wires on my harness? The mass air sensor is a rebuilt bosch unit, less than a month old. I'm not going to be able to mess with the car until the weekend. But any suggestions yo'uve got are great. Thanks, MIke
Le Mans Master
Joined: Jan 2003
Posts: 5,858
Likes: 7
From: Santa Maria CA
Re: TPI Question (Wheelman)
Code 12 means everything is ok :lol: :lol: Shows what the computer knows :lol:
You will get a code 12 at the begining and the end if all is well. If you get any codes in between the 2 code 12's, those are trouble codes.
Race Director
Joined: Sep 2003
Posts: 16,838
Likes: 341
From: Database Error Indiana
Re: TPI Question (i885744)
Make sure its actually getting gas. A freind had his injectors serviced and let them sit a long time before installing. They were stuck shut from sitting. :chevy
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Thread Starter
Pro
Joined: Apr 2004
Posts: 687
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From: Atascadero Ca
Re: TPI Question (joalyons)
yes, my dist is in correctly. I actually took it out and turned it around 180 degrees to see if that was it, it wouldn't fire at all. So i put it back to where i had it. Still fires a few times then quits. I'm used to old carbed hei chevy motors where the #1 spark plug hole is at about 5' oclock when properly timed. With this distributor i have it in at about 7-8 oclock to even get it to fire, is that normal for these motors? Its the small tpi distributor with 2 small plugs, 1 4 wire and 1 2 wire.
I have 2 wires going to my oil pressure switch, can i just jump the 2 wires and have it work for testing purposes?
[Modified by i885744, 5:14 PM 4/30/2004]
I have 2 wires going to my oil pressure switch, can i just jump the 2 wires and have it work for testing purposes?
[Modified by i885744, 5:14 PM 4/30/2004]
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: TPI Question (i885744)
For the engine to run, it doesn't matter where you end up putting the #1 spark plug wire. It can be at 6 o'clock, 12 o'clock or any where else for that matter. The engine doesn't know or even care.
All that matters is that the plugs are routed around the distributor cap in the correct order and direction, rotor is properly positioned and that the #1 piston is in the correct position (just before TDC on the compression stroke) when the #1 plug fires.
Positioning the distributor is mostly a matter of clearance. It's easier to turn/adjust and plug in the three electrical connections when it's oriented a certain way so that the cap doesn't hit the runners.
I don't know about cross connecting the oil pressure wires though. You can call PainLess and see what they say.
Jake
All that matters is that the plugs are routed around the distributor cap in the correct order and direction, rotor is properly positioned and that the #1 piston is in the correct position (just before TDC on the compression stroke) when the #1 plug fires.
Positioning the distributor is mostly a matter of clearance. It's easier to turn/adjust and plug in the three electrical connections when it's oriented a certain way so that the cap doesn't hit the runners.
I don't know about cross connecting the oil pressure wires though. You can call PainLess and see what they say.
Jake
Racer
Joined: Feb 2004
Posts: 251
Likes: 0
From: De Pere WI
Re: TPI Question (i885744)
I did the same thing to a 83 blazer and test drove it for the first time last weekend. Go to autozone and purchase a noid light to test your wiring to your fuel injectors they cost about seven bucks. The engine needs two things to run, fuel and spark. If you can narrow it down to one or the other the problems are easier to solve. With the noid light you can make sure that your injectors are getting the firing pulse they need to allow fuel to pass. I am pretty sure i trouble shot every single componet in the conversion process, some of the time because i was stupid. If you have the distributor out get the ignition module checked, i used advance auto because they checked it for free. You have to be able to rule out spark or fuel. My biggest problem was injectors were not firing in crank when warm because the system thought it was flooded. Hope this helps.
Thread Starter
Pro
Joined: Apr 2004
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From: Atascadero Ca
Re: TPI Question (redvtt)
i checked the fuel injectors with my light and they are getting pulse. Maybee i'll try to track down another mass air later on. If i just disconnect it will the computer go into some sort of default mode? i know fords to this, what about chevy's?
Thread Starter
Pro
Joined: Apr 2004
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From: Atascadero Ca
Re: TPI Question (i885744)
i noticed one of you is from sacramento, another from santa maria. Do you guys know anyone in the paso robles, san luis, atascadero area that might be able to help me out?
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
Re: TPI Question (i885744)
You can enengize the fuel pump by jumpering +12Vdc to ALDL pin G (lower left); you can also test for fuel pump power there. Since it's not OEM wiring, use a small in-line fuse to jumper.
I suggest you put a fuel pressure gauge (0-60psi) on the Schraeder valve on the fuel rail, jumper power to the fuel pump and verify that the fuel rail is primed and does not bleed down rapidly when power is removed.
The best test (the only one I've found) is substitution; the MAF from an '86-89 Vette or F-body will work.
When it fires up does the tach show some non-zero RPM reading?
I suggest you put a fuel pressure gauge (0-60psi) on the Schraeder valve on the fuel rail, jumper power to the fuel pump and verify that the fuel rail is primed and does not bleed down rapidly when power is removed.
The best test (the only one I've found) is substitution; the MAF from an '86-89 Vette or F-body will work.
When it fires up does the tach show some non-zero RPM reading?
Instructor
Joined: Sep 2002
Posts: 210
Likes: 0
From: Southfield Michigan
Re: TPI Question (65Z01)
You engine will run with the MAF disconnected. "Limp home mode", you will just run rich and get bas gas milage.
I removed the screens from my MAF and sucked a particle through it breaking the wire in there. Car still ran but I had a MAF code. Also to test it I un-plugged the MAF, car fired up and ran ok. It did surge a little tho.
I removed the screens from my MAF and sucked a particle through it breaking the wire in there. Car still ran but I had a MAF code. Also to test it I un-plugged the MAF, car fired up and ran ok. It did surge a little tho.
