Airstream 89 345LE GM454 Issue

[swebster]

Tom,
Good point. The mechanical pump could be the issue in this case. Also I just recently had an ignition module go all wonkey on me. Worked, didn't work, worked.

Replaces with NAPA Heavy Duty Lifetime Warrantee verison for $30. Well worth it. Also solved my intermittant no start issues I've had for almost six months.

[StingrayL82]

Originally Posted by ArStrm345LE

2007.08.22 UPDATE: I just got off the phone with the Mechanic and he said they had just re-timed the engine to 4 degrees before TDC. I respectfully mentioned to him that it was my understanding that the proper timing for this motor/moho was 8deg before TDC. He said they knew what they were doing as they have the proper documentation and they are an RV/auto repair shop. Are they correct? Can anyone possibly give me an intelligent response if the timing is indeed 8 before using the timing marks on the bottom of the engine using the 8th cylinder?

P.S. I couldn't seem to find the edit button for my above post to append this one. I apologise in advance for the double posting.

They are indeed correct. The proper timing for a 454 RV motor is 4*BTDC. If you were running a high performance 454 with 10.5:1 compression, you would set your timing at around 10*BTDC. If you find that your motorhome is sluggish, you might want to ask the mechanic to take a look at the timing chain. If the chain isn't as tight as it should be, consider a double roller timing chain. As for the motor running at bit warm (my L-82 350 Vette ran at 210 stock, and that was normal), have the mechanic take a look at the fan clutch. Fan clutches that work make a world of difference. I would also make sure that I had a 4 core radiator. Hope that helps.

Frederic

[txraz]

I have an '85 345 classic that I'm intemately familiar with having rebuilt the engine myself along with a multitude of other mechanicals. I too suffered from the fuel flow problem and had always replaced the mechanical pump when the frustration grew. After 15 years, I finally figured out my demons. The electric pump in the rear near the fuel tank is a very weak push pump which means it cannot pull fuel from the tank. On my rig the fuel pumpl was mounted about 1/2 down from the top of the fuel tank. That meant that for the first 1/2 tank of gas, gravety works as designed and feed the pump. However once the tank is lower than the fuel pump the small electric pump simply losses its effectiveness and when a grade is encountered the fuel flow is almost shut down. To fix the problem I mounted a high quality race pump as low as possible on the frame near the bottom of the tank and surely below the fuel pick up. I've run three tanks through it since the modification and feel confident I could climb everest without a chug.

Hope it helps.