86 GMC k1500 w/350 crate swap, horrible rev response and no power in gear.

[hypageck]

Warning, long post because I want to give as much info as possible.
Hoping to get some help.
To start off, I've searched the forums endlessly and haven't found anyone with my exact issues.
Specs -
86 gmc k1500, originally had 305 & 700r4. Quadrajet M4MED (NOT ccc)
Work done - essentially everything below the doors is new, short of the tranny which was *supposedly* rebuilt about 5k miles ago. Transfer case, brake system from the pedal to all 4 corners, radiator, all suspension, every bearing and seal that exists on the vehicle, body mounts, etc etc etc

Recent work leading to problems -
Spun a rod bearing on OEM 305 so I dropped in a new GM Performance 350 crate. 195hp version. Had my original intake manifold hot tanked, replaced the oem exhaust manifolds, new distributor, new spark plugs, reused plug wires (only 500 miles on them), new water pump, new alternator, new fuel pump and pushrod, new battery, new reman Quadrajet, reused flexplate (looked good with no cracks/wear), new external visible fuel filter(removed the one in the carb), new motor mounts, new TV cable for 700r4(mounting clip broke during removal), all new gaskets, new 8" harmonic balancer (I'm probably forgetting a few things)

Put on harmonic balancer per every instruction I could find and common sense (it really only goes on one way because of the key) and checked initial timing by looking down the oil holes in the valley to ensure balancer wasn't off at all. Painted marks on balancer to check for outer/inner movement. Installed intake and set intial timing to 12° btdc, primed oil system and installed new HEI dizzy and made sure it was visually close to firing on #1. Installed new carb with new mounting gasket. all Electronic Spark Control components unhooked, all emissions crapola removed, ran new vacuum lines for everything (brake booster in rear, TCC switch to manifold vac, dizzy to manifold vac). Reinstalled all pulleys and belts, etc

Fired engine up, set initial timing (with vac advance unhooked/plugged) to 12° BTDC, ran engine for 30 minutes @2k rpm with zinc break in additive. Engine ran fine the entire time and never had a problem. Drained it down, new oil/filter. Start truck up, went to go for a spin and this is where the problems happen -

Truck has NO power when in gear, feels as if the transmission won't let it move. Pull it out of gear, and it's delayed to respond (as if trying to build up speed), but will rev up. In higher revs, it's a lot more responsive. Back in gear, same problem. As if the engine won't spin up and isn't making any torque. My old 305 was very responsive at lower rpm and would occasionally break the tires loose on gravel, the new 350 won't even get out of its own way, feels like the brakes are locked up (verified they aren't) or as if the tranny is turning against itself. It's also VERY hard to push in neutral.

I've adjusted the timing 876 different ways - 10°, 12°, 4°, 8°, tried ported and manifold vacuum. Best running is 12°BTDC and manifold vac on V.A. can.
Set the TV cable per the GM service manual(press the release button, push adjuster toward firewall till flush, open carb throttle by hand to full and listen for clicks from the adjuster).
I've checked for vac leaks with ether on the base of the carb, all vac ports, intake manifold sides and front/rear

I originally tried to reuse my old dizzy as it has brand new rotor/cap/coil. I cleaned the insides of it and checked the V.A. can for proper movement. With this installed, the truck would eventually jump timing by 12-17 degrees and I'd have to pull it and start the timing process all over again. Before install I shimmed it for endplay and measured the gear against a new dizzy (1.225OD on both). Dizzy kept jumping timing during anything other than idle. Replaced dizzy and now it will keep timing.

Although it keeps timing, it just doesn't seem to have the power a new 350 would. My worn out 305 had more.

During a test drive, the vehicle had NO acceleration ability until higher rpms(3k or so).

TL,DR -new 350 has horrible power, won't rev up and vehicle hardly moves while in gear.

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Any suggestions and questions/comments are welcome.

 

[3504boltmain]

Warning, long post because I want to give as much info as possible.
Hoping to get some help.
To start off, I've searched the forums endlessly and haven't found anyone with my exact issues.
Specs -
86 gmc k1500, originally had 305 & 700r4. Quadrajet M4MED (NOT ccc)
Work done - essentially everything below the doors is new, short of the tranny which was *supposedly* rebuilt about 5k miles ago. Transfer case, brake system from the pedal to all 4 corners, radiator, all suspension, every bearing and seal that exists on the vehicle, body mounts, etc etc etc

Recent work leading to problems -
Spun a rod bearing on OEM 305 so I dropped in a new GM Performance 350 crate. 195hp version. Had my original intake manifold hot tanked, replaced the oem exhaust manifolds, new distributor, new spark plugs, reused plug wires (only 500 miles on them), new water pump, new alternator, new fuel pump and pushrod, new battery, new reman Quadrajet, reused flexplate (looked good with no cracks/wear), new external visible fuel filter(removed the one in the carb), new motor mounts, new TV cable for 700r4(mounting clip broke during removal), all new gaskets, new 8" harmonic balancer (I'm probably forgetting a few things)

Put on harmonic balancer per every instruction I could find and common sense (it really only goes on one way because of the key) and checked initial timing by looking down the oil holes in the valley to ensure balancer wasn't off at all. Painted marks on balancer to check for outer/inner movement. Installed intake and set intial timing to 12° btdc, primed oil system and installed new HEI dizzy and made sure it was visually close to firing on #1. Installed new carb with new mounting gasket. all Electronic Spark Control components unhooked, all emissions crapola removed, ran new vacuum lines for everything (brake booster in rear, TCC switch to manifold vac, dizzy to manifold vac). Reinstalled all pulleys and belts, etc

Fired engine up, set initial timing (with vac advance unhooked/plugged) to 12° BTDC, ran engine for 30 minutes @2k rpm with zinc break in additive. Engine ran fine the entire time and never had a problem. Drained it down, new oil/filter. Start truck up, went to go for a spin and this is where the problems happen -

Truck has NO power when in gear, feels as if the transmission won't let it move. Pull it out of gear, and it's delayed to respond (as if trying to build up speed), but will rev up. In higher revs, it's a lot more responsive. Back in gear, same problem. As if the engine won't spin up and isn't making any torque. My old 305 was very responsive at lower rpm and would occasionally break the tires loose on gravel, the new 350 won't even get out of its own way, feels like the brakes are locked up (verified they aren't) or as if the tranny is turning against itself. It's also VERY hard to push in neutral.

I've adjusted the timing 876 different ways - 10°, 12°, 4°, 8°, tried ported and manifold vacuum. Best running is 12°BTDC and manifold vac on V.A. can.
Set the TV cable per the GM service manual(press the release button, push adjuster toward firewall till flush, open carb throttle by hand to full and listen for clicks from the adjuster).
I've checked for vac leaks with ether on the base of the carb, all vac ports, intake manifold sides and front/rear

I originally tried to reuse my old dizzy as it has brand new rotor/cap/coil. I cleaned the insides of it and checked the V.A. can for proper movement. With this installed, the truck would eventually jump timing by 12-17 degrees and I'd have to pull it and start the timing process all over again. Before install I shimmed it for endplay and measured the gear against a new dizzy (1.225OD on both). Dizzy kept jumping timing during anything other than idle. Replaced dizzy and now it will keep timing.

Although it keeps timing, it just doesn't seem to have the power a new 350 would. My worn out 305 had more.

During a test drive, the vehicle had NO acceleration ability until higher rpms(3k or so).

TL,DR -new 350 has horrible power, won't rev up and vehicle hardly moves while in gear.

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Any suggestions and questions/comments are welcome.

So you've got a lot going on here, and with New this and New that, it would be hard to know where to start.
But I've got a sneaking suspicion that it might be carburetor issue but maybe it's the tranny. You didn't mention any spitting or backfiring so its hard to say weather its lean or rich. If that is what it is of course. The best way to check for vacuum leaks is with a vacuum gauge. Starting with the easiest diagnostic tools first though...
Spark plugs: check their condition
Check that you are getting spark on each cylinder
Did you reuse your old ignition module? if so, the auto parts store can test it.
Are you sure the mechanical timing was set correctly?
I do wonder about the tranny and torque converter... Or is this manual? Sounds like your "hard going in neutral" indicates its a manual. Check the fluids... eh, might as well check them all... but let the truck run for a while before you check the tranny fluid. Bubbling is an indication of problems from what I hear...
I also don't know peanuts about transmissions, so you are on your own there.
There's a lot of ground to cover here... Give these things a whirl if you want.

 

[1987 GMC Jimmy]

Yeah, several things came to mind when reading this. Words such as carb, transmission, and torque converter. I’d start from the basics. Make sure your initial and total timing are correct, and you’re getting good spark and then spark to every cylinder. Who rebuilt the carb? Make sure you’ve got good fuel volume coming from the pump. I was told that you should fill a 20 oz Coke bottle in 8 seconds if everything's right there. The carb is what worries me. Not because it’s a Quadrajet, but because I don’t trust big companies like Holley or Edelbrock to rebuild them right. Smaller specialty shops are the best thing for Quadrajets. Sometimes local guys know them, but I imagine those folks are growing in rarity. You should check the acc. pump function. Just look down the carb, move the throttle by hand, and watch for two healthy streams of gas that begin the instant you move the throttle. If you see drips or lapses in the stream, you have a problem. I’d like to know what you’re vacuum does on a gauge, as well. Just to make sure it’s not something that’s harder to check like a bad intake manifold gasket giving you trouble. I’d also suggest checking your transmission fluid. That’s strange that it’s hard to push.

 

[4WDKC]

1 did you check to make sure the ports from the 305 intake were the same size as the heads/gaskets for the 350? I trust no one
2 you said you installed a balancer the one from the 305 or one for a 350? Did you verify TDC was correct on the mark if new balancer was used?
3 you indicated you got a new dist. what did you get? Reverse polarity on the pickup coil will cause it to have these symptoms. Had one do it to me, took long time to figure out.
4 you havent mentioned if it smokes from running rich, tries to die or torques up at idle when put in gear. Any high idle when warm?

 

[Dougnsalem]

1 did you check to make sure the ports from the 305 intake were the same size as the heads/gaskets for the 350? I trust no one
2 you said you installed a balancer the one from the 305 or one for a 350? Did you verify TDC was correct on the mark if new balancer was used?
3 you indicated you got a new dist. what did you get? Reverse polarity on the pickup coil will cause it to have these symptoms. Had one do it to me, took long time to figure out.
4 you havent mentioned if it smokes from running rich, tries to die or torques up at idle when put in gear. Any high idle when warm?

#2 is a good one. I've gotten burned on the different timing tab/balancer deal a couple times. Yeah, I'm not a quick learner.... Lol

 

[hypageck]

2 you said you installed a balancer the one from the 305 or one for a 350? Did you verify TDC was correct on the mark if new balancer was used?

#2 is a good one. I've gotten burned on the different timing tab/balancer deal a couple times. Yeah, I'm not a quick learner.... Lol

This was the problem. Got a balancer that should be read @ 1200, needed one to be read @ 0200. Bought a new balancer, all issues vanished.

Do y'all have any input as to the best initial timing for this engine? I started at 12 BTDC and been running for about 15 miles. It runs a whole lot better than the 305 did, but seems like it might be still a bit too retarded.

 

[Honky Kong jr]

This was the problem. Got a balancer that should be read @ 1200, needed one to be read @ 0200. Bought a new balancer, all issues vanished.

Do y'all have any input as to the best initial timing for this engine? I started at 12 BTDC and been running for about 15 miles. It runs a whole lot better than the 305 did, but seems like it might be still a bit too retarded.

Give some more timing until it turns over hard. Then back it down. If it pings while accelerating back it down a little more or upgrade your gas.

 

[4WDKC]

This was the problem. Got a balancer that should be read @ 1200, needed one to be read @ 0200. Bought a new balancer, all issues vanished.

Do y'all have any input as to the best initial timing for this engine? I started at 12 BTDC and been running for about 15 miles. It runs a whole lot better than the 305 did, but seems like it might be still a bit too retarded.

Follow recommend timing for the engine for initial then small increases between revving the engine in park. I do this till it revs clean with no hesitation, then take it for a drive and test acceleration at WOT while listening for ping (this is where a quiet exhaust and efi have a big advantage).

 

[twinturbo427]

Just an additional thought,
If the vehicle sat for more than a month with gas in it while you did the engine swap, burn all the fuel out and then a tank or so before advancing the timing. That old gas will make it ping even when everything is set-up correctly.

After my tranny change and new fuel pump (and tbi reg due to stupidity) my fuel looked funny. It even had Stabile fuel saver in it. It pinged at part throttle cruise until the second tank of fuel.

 

[hypageck]

Give some more timing until it turns over hard. Then back it down. If it pings while accelerating back it down a little more or upgrade your gas.

Follow recommend timing for the engine for initial then small increases between revving the engine in park. I do this till it revs clean with no hesitation, then take it for a drive and test acceleration at WOT while listening for ping (this is where a quiet exhaust and efi have a big advantage).

I'll incorporate both this weekend when I'm off work and able to play with it more. It'll be hard to hear ping with dual 2.5" to 18" glasspacks though

Thanks for y'alls help

 

[4WDKC]

I'll incorporate both this weekend when I'm off work and able to play with it more. It'll be hard to hear ping with dual 2.5" to 18" glasspacks though

Thanks for y'alls help

Maybe add some mufflers so you can hear it while adjusting this, then swap back if desired.

 

[OkieFishMan]

I always total time my engines. When I installed my new intake, carb, and ignition system on my big block, I just total timed it to 34 degrees at 3000 rpm. You need a timing light that is made for doing that though.

 

[3504boltmain]

Give some more timing until it turns over hard. Then back it down. If it pings while accelerating back it down a little more or upgrade your gas.

I'm going to have to agree with Honky, hypageck. Keep a timing light on hand, but doing it by ear seems to work best. Take note of what you set as sounding "smooth". Then bump it around from there. Modern gas ain't no good, and Timing methods need to change accordingly... But it's anyone's guess as to what's right anymore.

 

[Dougnsalem]

I'm going to have to agree with Honky, hypageck. Keep a timing light on hand, but doing it by ear seems to work best. Take note of what you set as sounding "smooth". Then bump it around from there. Modern gas ain't no good, and Timing methods need to change accordingly... But it's anyone's guess as to what's right anymore.

X3
I do it exactly as Honky explained. I couldn't tell you the last time I used my timing light. Its been years....

 

[Honky Kong jr]

Strip tuning for the win!!! Lol