Pigpen's Poor Passing Power Problem

[Jrgunn5150]

See what I did there?

Anyway, for those who don't know, Pigpen is a 8600 GVRW K2500. 4L80E, 5.7 Vortec, 3.73 gear's, 265/75r16 tires. A basic truck.

Pigpen, runs like an utter turd off the line, and will not spin a tire, even in the rain. It ran the same last night with one plug wire pulled off it. It does pull cleanly to 5600 or wherever it shifts at at WOT, but the tip in, just sucks.

I understand 4L80's have a taller first gear, I understand I only have 3.73's, I understand it's not a race car, I understand it's just a small block in a 3.4 ton. I'm not asking for flames out of the tail pipes and all that Fast n Furious BS, I'm just asking for some off the line, which, IMO, it should have something there.

Thing's I have done so far,

New shift solenoids and wire harness inside the trans

New Autolite XP 605's gapped to .055

New Jeg's 8.5mm MSD copy wires

New air filter

Gutted the cats

None of this has made a difference in the throttle response or low end the truck has. It has 58 PSI of fuel pressure, it is not popping any codes other than for the missing cats now. I do not know if it has an upgraded spider, the previous owner say's he never did anything with the injectors, and was truthful about everything else. He owned it for 10 years, so I'm going to say it probably has the stock poppets, even though it really looks like the intake has been off it before.

So, if anyone has any ideas, I'm all ear's. I just ordered a new distributor today, I'll do the ICM and coil after that, then I guess I'm onto the spider.

 

[65nightmare]

My buddy had the identical truck and problem and it ended up being the cap was crack. We couldn't figure it out until we pressure washed under the hood (because it was a plow truck) and it wouldn't start then 2 days later it fired right up. So we changed the cap and rotor and low and behold you didnt need the snow plow on to do burnouts.

 

[Jrgunn5150]

My buddy had the identical truck and problem and it ended up being the cap was crack. We couldn't figure it out until we pressure washed under the hood (because it was a plow truck) and it wouldn't start then 2 days later it fired right up.

Twice I've washed under the hood of this truck, and not spraying the distributor like a fool, and twice it failed to start for a bit afterwards. I did have the cap off today, and it didn't have anything obviously wrong with it, but you could be on to something there. Maybe I'll spray it tomorrow and see.

 

[65nightmare]

Lol your going to spray it like a fool.
Im sure you know because your from up nort like me but plow trucks have constant water all over under the hood from powder snow coming up from underneath because the bottom valance is gone for the plow mount. So salt also gets up there and if you dont like corrosion frosting on everything you have to pressure wash it.

 

[Jrgunn5150]

Lol your going to spray it like a fool.
Im sure you know because your from up nort like me but plow trucks have constant water all over under the hood from powder snow coming up from underneath because the bottom valance is gone for the plow mount. So salt also gets up there and if you dont like corrosion frosting on everything you have to pressure wash it.

Yeah, I don't drive it to work or anything right now, so it's worth trying to find out for sure what the issue is. My new distributor does come with a cap also.

 

[65nightmare]

Yeah, I don't drive it to work or anything right now, so it's worth trying to find out for sure what the issue is. My new distributor does come with a cap also.

I was just joking but the new cap on the dis is a +

 

[65nightmare]

I just read your other thread and is the spider still leaking because (this is just food for thought) water and petroleum are attracted even though they dont mix they do stick to one on other there may be water getting in the leak.

 

[beardeddummy]

Coil? Ignition control module

 

[Big D]

Id say do a simple leak down test before throwing anymore money at it. also Id make sure the timing is correct as well when you put that new distributor in.

Does the fuel Pressure hold or does it leak down?

easy way to see if you have stock injection is yank that throttle body and peak inside with Mechanics mirror, you can also see if theres leaks.

I thought I read somewhere about a tech service bulletin about vortec engines using iridium plugs to set the gap at .040... Cant find it right now though of course.

 

[Jrgunn5150]

Id say do a simple leak down test before throwing anymore money at it. also Id make sure the timing is correct as well when you put that new distributor in.

Does the fuel Pressure hold or does it leak down?

easy way to see if you have stock injection is yank that throttle body and peak inside with Mechanics mirror, you can also see if theres leaks.

I thought I read somewhere about a tech service bulletin about vortec engines using iridium plugs to set the gap at .040... Cant find it right now though of course.

Damn, that's a good idea, idk why I didn't think of that lol.

Since I worked until five am, and have to be back in an hour, it'll have to wait until tomorrow, but I'll pull that TB then and take a peak