Hello everyone.

I’ve been reading and searching through posts on this board for a little over a month now and I’ve found a TON of great information. Unfortunately I haven’t fixed my problem yet. I just recently bought a 1984 K5 Blazer from a guy who performed a carb to TPI swap. The engine is a rebuilt 350 V8 from an ’89 Blazer and he used the complete TPI system from an ’85 IROC. I’ve been told by my Blazer forum to come here because this is where the TPI wizards are at.

The truck starts perfectly each time it’s cranked. It idles nicely and for the most part it drives well. The only problem is at low RPMs in the range of 1mph to around 15mph. The engine seems to ‘bog-down’ in this range and it is only corrected if I give it a fair amount of gas. Once I get above 15-20 mph it’s smooth sailing. It does this each and every time that I get back into this range. If I stomp on it from the start then it speeds up well with no hesitation.

Also, the fuel pump runs constantly when I turn the key to the accessory ON position (but before I actually crank the engine). In my other car (a ’93 Z28) my fuel pump will pressurize and then stop, but this isn’t the case with the Blazer. I’m not sure if this is the root of my low RPM stumble or not but I thought it was worth mentioning. One extra item to note is that all emissions have been removed from this motor. Most things I’ve read on this type of problem seem to be solved with an EGR fix, but that won’t work in my case.

I’ve cleaned my IAC and I’m replacing my TPS tonight. Any info is greatly appreciated.

Thanks!

 

Last night I replaced my TPS and then set the voltage to 0.54V. That didn't change anything. I guess next I'm going to check the fuel pressure and then adjust the timing. After that I'm clueless as to what to do. TPI wizards..........help please.