Recent Posts

1

Fuel Systems and Drivability / Re: No Start TBI

« Last post by VileZambonie on Today at 01:43:50 pm »

Did you click the link?

2

Members Rides / Re: 1987 Silverado V10 from the frozen north

« Last post by Shifty on Today at 11:47:02 am »

heck yeah! 

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Fuel Systems and Drivability / Re: No Start TBI

« Last post by catbird7 on Today at 07:07:28 am »

Explain, "two cavities at the ecm"? You need to dumb this down for me.

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Members Rides / Re: 1987 Silverado V10 from the frozen north

« Last post by nbarr7 on July 14, 2025, 07:16:42 pm »

I get behind updating things here. Like was suggested, oil pressure was just a gauge malfunction. It drives great.

That said, since November I have put much of the interior back together, after adding some sound dampening to the floor under the carpet. I re-sprayed/dyed burgundy some eBay door cards (my body guy broke both mine) and got new carpet lowers (old owner cut speaker holes). Replaced all the window gaskets, and now am looking to replace the frame on the passenger smoker/vent window - just have to find my rivet gun before drilling it out. Got a new repro rear bumper, and a rust-free front bumper. Re-spray painted the headlight bezels silver for clarity. Added a new bed bolt kit, so that's locked down now. mud flaps (minor) What else have I done...? New side trim, emblems, fuel injection emblem (my original one on the new repro tailgate!) Lots of odds and ends etc. Still need to do the headlienr, but I'm driving this thing this summer! Already put over 100 miles on it in the last few weeks (I live in the country, so everything is at least 10 miles away ha).

Got some tubby steering, but I haven't yet replaced tie rod ends etc, so likely I'll do that soon-ish. But for now, I'm putting the miles on enjoying it!

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Fuel Systems and Drivability / Re: No Start TBI

« Last post by VileZambonie on July 14, 2025, 07:12:59 pm »

http://forum.73-87chevytrucks.com/smforum/index.php?topic=37738.0

If you are certain ECM B has power in and out of the fuse, check at the two cavities at the ECM as seen in the link I posted.

6

Fuel Systems and Drivability / No Start TBI

« Last post by catbird7 on July 14, 2025, 05:56:24 pm »

1987 R10 305 4spd manual 4x4. No pulse to injectors. So far I have purchased new fuel pump, new fuel filter, new fuel pump relay, completely new distributor, and new computer. Verified power at both ecm fuses and verified the fuses are good. Overriding the relay, forces the fuel pump to run and provides fuel pressure at the injectors however will not spray. 9 volt battery applied to injectors produces good spray  from both injectors and allows the engine to run but only until the initial sprayed fuel is burnt. I have no check engine light at all, and I pulled the instrument panel apart and verified the actual bulb for check engine light is good. I'm lost!

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Heating, Ventilation & Air Conditioning (HVAC) / Re: Blower motor

« Last post by Happytexan on July 12, 2025, 11:31:03 pm »

Wow! Thank you! The blower does run all of the time with key on. Have been told before that it’s to keep fresh air in the cab to combat CO from accumulating. Thank you for explaining the thermostatic switch. I was wondering what that is. The trucks I’ve had experience with have all been 77-79 models. It’s interesting to see the progression made in this body style. The other issue I’m trying to figure out is why the idle mixture screws on the q-jet do nothing. Found the carb mount gasket bad, good size vacuum leak. Replaced it with a new fel-pro gasket. Have capped off all of the vacuum ports on the carb accept the booster and vacuum advance. Put new hose on those. Need to cap off the intake manifold vacuum outlets for the trans and hvac to eliminate those possible sources as well. With the mixture screws in, I can turn the idle down 550 rpm and it purrs just fine. I backed the idle screw a half turn past the point of the engine dying to see if the blades were past the proper transfer slot alignment. Turned the screws out 2 full turns each and it made 0 difference. No start/no idle.

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Members Rides / Re: 84 Jimmy Build

« Last post by 1981lt1 on July 12, 2025, 12:06:52 pm »

Don't even fiddle with those gaps til you are sitting on your good body mounts.

Yup.  Got some bushing parts on order since I don't quite trust the original bolts and washers.

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Heating, Ventilation & Air Conditioning (HVAC) / Re: Blower motor

« Last post by VileZambonie on July 12, 2025, 07:00:10 am »

74 is a different system that uses a thermostatic switch which you can see in the engine bay side of the evaporator case and a high side pressure switch in the liquid line. Later models just used a low pressure switch at the accumulator. Low 2 Mediums & High are your only options for fan speed with technically no fan off option. Key on it should come on and run at whichever speed the selector is at. The ground wire should jump off the blower housing and to the firewall. When the blower stops working you need to be ready to pinpoint where it is dropping out and why. It sounds like you could have compounded issues, so I would address them one at a time.

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Heating, Ventilation & Air Conditioning (HVAC) / Re: Blower motor

« Last post by Happytexan on July 12, 2025, 12:57:30 am »

I followed your t/s instructions and found the fuse had been replaced with a breaker by the PO. All connections good, ground is good. My first truck I had almost 30 years ago was a 78 big 10 camper special with a 400 small block. Being a 78, that truck had different a/c modes. The 74 I now have only has one a/c option. No max option. So when you put the mode switch on a/c, it switches the blower to high speed, the same way my old 78 did on max a/c. If I switch it to bilevel, then all 4 blower speeds work as they should. This now has me wondering if the later hvac controller with multi a/c settings will work in my 74. Thanks again for the help and tech info.