Got a Bogging Issue

[Zonaman]

I’ve got an engine bogging issue. It only occurs when I’m on this one stretch of highway always at about the same place. I’m hauling my boat to the lake (700R4 not in overdrive). I’ll do about 20 minutes at 65 on the freeway, exit and do I’m doing a few miles of surface street driving with a few stop lights. Then I’ll get on this stretch where the speed limit goes from 45 to 50 and it’ll bog down a few times on acceleration. Then it’s fine. Only does it on the way up- a gradual incline the whole way in. This is Central Arizona so it’s usually around 100 and the engines pretty warm but not overheating. I’ve got HEI and an Edelbrock 1406. Any theories who the "Boggie-Man is? Thanks.

[tutone]

I just chased a similar ghost. Tried everything.Ended upswapping another 1405 Edelbrock from my car and problem solved. Mine would bog and surge at 55 pretty much every time. The guys on the forum were very helpful in suggestions too. Truck runs better than ever.

[Zonaman]

That 1406 has about 65k miles's on it.

[68 P.O.S.]

At 65K it wouldn't be a bad idea to throw a rebuild kit at it...a calibration kit too.

[tutone]

Originally Posted by Zonaman

That 1406 has about 65k miles's on it.

Maybe so. Mine had far less than that. The crappy gasoline that they sell will eat away at the rubber parts in any carb. There are a ton of things to try, timing, vacuum leaks, ignition parts, plugs, wires, whatever, but I'm just saying, I wish I had started with the carb.

[Zonaman]

Been decades since I've rebuilt a carburetor. But it wouldn't hurt to do it. Either that or maybe put that Sniper EFI on it😉

[LNP]

Could be a weak fuel pump brought out by the up grade. Or a clogging fuel filter

[Zonaman]

Originally Posted by LNP

Could be a weak fuel pump brought out by the up grade. Or a clogging fuel filter

Fuel pump is new, but I ought to replace that filter. Might be cheaper than an EFI unit

[RichardJ]

>>Only does it on the way up- a gradual inline the whole way in.<<

Ok, leave the rest of the story out and say exactly what it is or isn't doing.

"Bogging" generally means you apply more throttle and the engine falls on its face and even slows.
Are you trying to accelerate and the engine is flat and won't accelerate?
You said 45 & 50 posted speeds. Do you know what the rpm's are, what gear the trans is in.

[Zonaman]

Originally Posted by RichardJ

>>Only does it on the way up- a gradual inline (incline-as in up hill) the whole way in.<<

Ok, leave the rest of the story out and say exactly what it is or isn't doing.

"Bogging" generally means you apply more throttle and the engine falls on its face and even slows. Yup, that's what it means

Are you trying to accelerate and the engine is flat and won't accelerate? Yup

You said 45 & 50 posted speeds. Do you know what the rpm's are, after the shift approaching 1900 what gear the trans is in. 3rd

That's pretty much it. Once again, it only does this somewhere along a 10 mile stretch of the road, maybe once or twice. It may do it coming off a stop light in 2nd also around 1900 rpm but usually when I'm in 3rd. Naturally the rpms drop off when it slows.

[body bolt]

With very warm temperatures, I had a very similar issue with my '91 Mercedes 300TE on the gradual grade on I-40 between Needles and Kingman. The thing would cough and spit so that I'd pull off and use the frontage road. I could keep going as long as I wasn't greedy with the pedal. As I climbed and got to cooler temps just outside Kingman, it would clear up. When this would occur I could hear 'the' fuel pump cavitating. The 'the' is in quotes as it turned out one of the two pumps wasn't working at all. Mercedes had two identical pumps in series as a remedy for this issue.

[tdangle]

Sounds like you are going lean on that stretch, especially with the high temps. I would recommend you get a AFR gauge and then you can see exactly what it is doing. Next step would be a calibration kit for your carb. Edelbrock makes it very easy to calibrate your carb to fit your engine. also are you running some sort of heat isolator for the carb mounting?

[garyd1961]

Try the simple stuff first fuel filter, air filter, spark plugs, check timing, upgrade the gas octane.

[HotWheelsFan]

I agree, sounds like a lean condition symptom.

Is this a problem that has always been there, or a new condition?

If it's a new problem - Carb overhaul may solve the issue.
If old - May need different jet, power valve spring to help.

Of course fuel delivery to the carb must be good and no timing issues present.


Bob

[Zonaman]

This is a new condition. Certainly won't hurt to replace the filter and rebuild the carb It may take a while, but I'll let you know when it all shakes out. Meanwhile, any other theories and suggestions appreciated. Thanks.

[Getter-Done]

Defiantly sounds like a carburetor needs attention.
Have you check to see if your Mechanical Advance Curve Weights are stuck shut?
If they are that could be adding to the issue.

[fdbdw]

Check carb floats and adjust as necessary

[Palf70Step]

As mentioned, change fuel filter. Before I go into a carb I do what has become know as the "Italian Tune-up" Get it running and slowly poor Seafoam or Barryman's B12 down the carb while keeping it running. That normally solves some small issues on my stuff without a rebuild. I try and run the SeaFoam or Barryman's B12 stuff every other tank.