Ramjet 350 Mefi 4 Behavior

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buffy
Posts: 113
Joined: Thu Aug 23, 2007 5:24 pm
Location: Longview, Texas

Ramjet 350 Mefi 4 Behavior

Post by buffy »

Hi Folks: Been awhile. I'm jacking around with my dad's '78 Blazer running a Ramjet 350. On cold startup, when I shift it into reverse it will stumble and die. Shift back to park and repeat, all is good and on my way. Any ideas on what's happening? This happens every time on cold start.

After it's fully warm, I get a few shakes at stop lights that fell like misses? Any idea of the garbage the computer is seeing.

stroker97k1500
Posts: 2702
Joined: Thu Apr 12, 2007 6:13 pm
Location: Macon Ga., 94Toyota truck with LSX stuff

Post by stroker97k1500 »

What is your fuel pressure?

orange ss
Posts: 218
Joined: Thu Aug 30, 2007 1:12 pm
Location: Emory, Tx

Post by orange ss »

IAC sticking?

Hog
Posts: 5036
Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

Post by Hog »

On a stock Vortec 350 truck, there is an input into the PCM which momentarily decreases idle rpm when the trans is shifted into drive/2nd/1st and into reverse.
On the MEFI 4 ECM is there an input from the shifter?

This sounds merely as the result of the load of the trans being applied on the engine. Sounds like the IAC cant keep up.

The stock Ramjet 350 calibrations are VERY rich so far as WOT or Power Enrichment tuning. Big gains are to be had by getting these ECM's retuned, or by swapping to 0411 PCMs and retuning.

311rwhp is damn good from a stock Ramjet 350. Controlled by 0411 with a dyno tune.

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peace
Hog

buffy
Posts: 113
Joined: Thu Aug 23, 2007 5:24 pm
Location: Longview, Texas

Post by buffy »

So glad to hear y'alls input. All the odd behavior centers around idle. Can the MEFI 4 be tuned effectively. There's a guy in town that focuses on dyno tunes. Can't think what he uses to flash them. I don't think there's any shifter input from the TH350. Just seems like it struggles with idle conditions.

stroker97k1500
Posts: 2702
Joined: Thu Apr 12, 2007 6:13 pm
Location: Macon Ga., 94Toyota truck with LSX stuff

Post by stroker97k1500 »


buffy
Posts: 113
Joined: Thu Aug 23, 2007 5:24 pm
Location: Longview, Texas

Post by buffy »

Thanks Stroker

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