Affordable fuel injection tbi kit questions.

Hello all I bought a tbi kit from affordable fuel injection. It's on a 1975 chevy c30 with a 350. The tbi kit is basic and has no emissions controls on it. My question is why when I come to a stop it stalls out and dies (only sometimes out of no where. No sighns before it dies) I have replaced the distributor, cap ,rotor ,wires o2 ,sensor ,map sensor ,iac and coolant temp sensor. I also put in r45ts spark plugs I don't know if that makes a difference on tbi. Thank you

Do you have a way to watch live data from when it’s running? Have you asked the company you got the EFI system from?

could be a whole list of things but are you running a fuel pump in tank or external?

Is this even a GM-based system, or some aftermarket kludge?

Most likely being caused by the absence of a VSS. The VSS plays a big part in the system idling correctly.

Sean Buick 76 said:

Do you have a way to watch live data from when it’s running? Have you asked the company you got the EFI system from?

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I will have to get my dad's scanner and I should be able to watch it. I have contacted them and I went through there diagnostics but none of it has pointed to an actual answer for my problem.

tayto said:

could be a whole list of things but are you running a fuel pump in tank or external?

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It is a internal pump. I ordered it as a 1990 chevy r3500 with a 350 for the tank and pump.

Schurkey said:

Is this even a GM-based system, or some aftermarket kludge?

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It is gm based

L31MaxExpress said:

Most likely being caused by the absence of a VSS. The VSS plays a big part in the system idling correctly.

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The system that I ordered does not require a vss but I do see what you mean. I had a 94 that I unplugged the vss and kind of ran the same way but not exactly.

Have you had a chance to remove all 8 spark plugs to see if they are all happy? I would start with that.

Yes I have all were good except for 4 and 6. I had a vacuum leak on the intake gaskets and replaced them at the same time as my other truck. They were burning lean it looked like which makes sense. I got in contact with affordable fuel injection they told me my idle was to low. They sent me directions on how to adjust the idle. I'll try that and check my plugs again after everything. I will update once I get this done.

sounds to me that the idle air control needs tweaking

How did they have you tie the MAP sensor into the intake manifold? Got an installation manual, and parts supplied sheet you can you share with us? Maybe a schematic? A trouble shooting procedure? How is intake air temperature calculated with that system? MAP sensor data can be converted to air mass data using the speed-density method. Engine speed (RPM) and air temperature are also necessary to complete the speed-density calculation.
Got access to a tailpipe sniffer, as that is how it was done in the day for emissions testing?
It's a pricey system you have there, and if you are respectful with your vendor they have every reason to help and increase sales. Nothing like a happy ending to get others to loosen their purse strings. My shop teacher, Mr. Silvey said, "Put your mind in motion before you put your mouth in gear".
Not a lot of that happening today.