Vehicle Pulls Hard Stumbles Then Pulls Hard Again.

[OldCrLvr]

Ok, here is the situation: The vehicle pulls strong then sputters a bit at about 3000RPM. After a second or two it decides it wants to pull hard again to 7000RPM. We have played with this thing for a couple weeks now. The vehicle was purchased as an untouched all stock 65 El Camino 283/Powerglide car. We carefully removed everything that wasn't necessary to drive (it's a retro 60's super stocker now) and installed an all new drive train. It does have the stock 10 bolt 3.08 open rear. So we have nothing to compare it to from before.

 

 

The engine is a mild 30 over 327. It has stock 4 valve relief pistons, Comp XE262S cam and an otherwise stock bottom end. The heads are port matched double humps with 1.94/1.50 valves and K Motion 1.25" springs with Summit roller rockers. The intake is an old 60's Edelbrock with a 1" spacer between it and a 600 Holley vacuum secondary. The ignition is the cars original Delco distributor with a Pertronix kit and matching coil. The exhaust is a set of Hedman Shortie headers with about 3' of 3" pipe to Summit 16" glass packs. There is then another foot or so of pipe with turn downs.

 

 

The transmission is a TH350 with a 2600RPM converter.

 

 

Now for the details. We have been able to make it run the best with minimal hesitation with: The carbs secondary spring has the short yellow one and #66 jets. The mechanical advance is a Mr. Gasket set (926G) which is supposed to have the advance in by 2000-2800rpm. We currently only have a way to check timing at initial. We found it to be best at about 10 degrees after. Which is also what the Mr Gasket destructions said to start with when using their advance kit. It did do the hesitation worse with the stock springs and weights.

 

 

Does anyone have any ideas? We were thinking it sounded like timing. But have so far ran out of ideas.

[angelic0-]

Sounds like a nice truck... throw in some pics of the truck on the outside...

 

Have you checked the connections on your blaster coil?

 

What ignition system do you have ?

[Stevens03]

I'd start looking at the ignition from what you've said. Maybe a nice msd 6a to boost the spark would help.

[Mike G]

Is the 3000 about when the secondaries start to open? How new is the carb? Have you tried running it without the spacer below the carb?

[OldCrLvr]

Is the 3000 about when the secondaries start to open? How new is the carb? Have you tried running it without the spacer below the carb?

Acording to the Holley spring kit, this spring is supposed to kick in around 2600 per the box.

 

It's hard to say when the secondaries are coming on. The carb is a couple years old. It was running fine on my fathers Elk and we pulled it off to put a bigger one on. I did pull the bowls and checked the float level.

 

No we haven't tried running it without th spacer. I personally haven't had any issues with spacers. I wouldn't think it would cause a bog. Do you think it is a possable issue?

 

Now, what I was just thinking is that the carb has a 6.5 powervalve. The vacuum is only 8-10. Could this be a possable issue?

[OldCrLvr]

Sounds like a nice truck... throw in some pics of the truck on the outside...

 

Have you checked the connections on your blaster coil?

 

What ignition system do you have ?

 

I will see if I can get some pictures up. They may be too large to upload.

 

The Coil seems to be fine and dandy.

 

the ignition system is the 1965 Delco distrubutor with pertronix electronic ignition kit, and Mr Gasket (part number 962G) weight/spring kit. It has the matching Pertronix kit.

[OldCrLvr]

This is a picture of the cars good side. This was after we towed it home. It looks quite a bit different now. But I don't have any current external pictures.

[OldCrLvr]

Heres another picture. I was wrong on the last caption. These pictures are of the bad side.