TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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Hi i have a 350 chevy in front of a 5 speed manual trans in an s10 pickup with the TPI intake from a 1990 camaro atop this engine combo. but i'm having issues with it starting... i have the GM service manual for a 1991 firebird and have went threw the diagnostics for the no starting problem. heres the deal, it has gas, a brand new delco fuel pump, 37 lbs of fuel pressure, good spark, it pulses the injectors, the SES light functions and shows only code 12, has the right TPS voltage but it is still not getting fuel into the cylinders. I have put a snap-on code reader on it and all i have noticed is that it doesnt show the rpm while cranking and i followed the books advice to test the reference wire to the Distributor with a test light to 12 volts and it should show rpm on the scanner and it doesnt, i have replaced the ECM and the igniton module. Also the other thing it does is after cranking the fuel pump runs and runs but takes a while to stop and when it does it bleeds the pressure off.What else is there to do? ANY help from a knowledgeable person would be GREATLY appreciated!!
I think fuel pressure s suppose to be at 45psi. It sounds like it is fuel related. But you also said it is not showing rpm's when cranking. It might be the pick up coil. Maybe someone else can chime in on this.
Do you have a good/correct ESC? I seem to remember reading that they're different for a 305 and 350.
__________________ 88 Trans Am - Spohn SFC's, Spohn Panhard Bar, Spohn F & R Sway Bars, and Spohn Wonderbar, Eibach Pro Kit Springs, Hotchkis LCA's, Dynomax Ultraflow cat back, Magnaflow cat and headers, LT1 cam.
yea i was thinking the fuel pressure was supposed to be around the 45 mark so the regulator is probably at fault for that and i'm leaning more towards the pickup coil because the ECM and prom was on a running engine less than a year ago so i'm not sure. but where do you find the numbers for the ESC module and does anyone have the right prom IDs thanks
it has been a while my goal for tomorrow is to take the fuel rail off the manifold and have each of the injectors in styrafoam cups and crank it so that the injectors would be visible and could tell if they are in fact pulsing or not.. from there i could limit the possibilitys quite a bit down to timing and other issues
Just remember that gasoline will melt a styrofoam cup in less than a minute. (Been there, done that..lol)
__________________ 88 Trans Am - Spohn SFC's, Spohn Panhard Bar, Spohn F & R Sway Bars, and Spohn Wonderbar, Eibach Pro Kit Springs, Hotchkis LCA's, Dynomax Ultraflow cat back, Magnaflow cat and headers, LT1 cam.
well the pressure reaches about 40 (tested today) but drops off when the pump shuts off, took the fuel rail loose and cranked it and it showed no signs of fuel spray, the Snap On Scanner said that the VATS wasnt a problem and was disabled.... when it was all together me and my buddy tried the ether idea except with a **** load of carb cleaner (less harmful on my head gaskets) and it would run perfectly fine but would just die out like it ran out of fuel... i am thinking it has to be either the prom or the pickup coil in the distributor.... any ideas let me know
well the pressure reaches about 40 (tested today) but drops off when the pump shuts off...
I wouldn't worry about the fuel pressure for now.
Quote:
Originally Posted by keplper68
...took the fuel rail loose and cranked it and it showed no signs of fuel spray...
the Snap On Scanner said that the VATS wasnt a problem and was disabled...
Suggest disabling spark to prevent a fire by removing coil wire, or connecting it to ground.
The dizzy ICM must be connected when testing for injector signal or the ECM will disable the injectors.
Can I assume the S-10 is a 1991 since you're using a 1991 Firebird manual, and that the VATS was disabled (reprogrammed EPROM) by someone else?
Quote:
Originally Posted by keplper68
it has gas, good spark, it pulses the injectors, the SES light functions and shows only code 12, has the right TPS voltage but it is still not getting fuel into the cylinders
You've proven:
It will run with starting fluid/equivalent
It has sufficient fuel pressure
It does have an injector pulse
injectors are not flowing, this doesn't mean the ECM/PROM is at fault because that would contradict the last quote above.
This leaves the injectors themselves, bu they may only need cleaning as someone has already stated, they're probably clogged.
I'm sure you can get a shop that refurbishes injectors to at least test them for you. Unless a good samritan will pull one of theirs out for you to use.
It takes a lot of gummy stuff to clog 8 injectors, might want to clean the gas tank, fuel lines, regulator, and rails before putting the injectors back in, or you'll run the risk of clogging them again.
alright this does give me some really good ideas and i think what i have someone test/clean them... anyone know of a good place to send these to have this done?
I had the same problem when i did my TPI swap. It turned out to be the injectors were seized since they were sitiing for a long time w/o any fuel. I had a buddy tap the injectors while cranking and it finally started.
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