help me please engine problems

[jeb conde]

hi i have a ram jet 350 w/ a th350 trans when i gas it stalls out jerks and sometimes backfires what sounds like through the air filter any help will be a god sent please get back to me soon anyone if this continues i may go completely crazy

p.s. the engine is new less than 50 miles on it

[pushrod243]

Hey Jeb

Welcome to the wonderful world of the ramjet! As you have probably already discovered you dealer is of no assitance. Hell so far the GM engineers ive spoke with dont even know a lot about the Ramjet. I have a 502 but the ecm is the same. If its fairly new you should have a mefi4 system. Have you checked it for codes? Mine had 2 codes i resovled one by replacing a bad relay supplied by chevy with the motor. And the other was an interference problem which may be causing the symptoms your car has. The 5 volt reference for the tps was out of range. I had wire tied the harness real neatly on the manifold. Once i removed the wire tie and moved the wires away from the ful rail my 5 volt reference became steady and my codes would reset. If you have no codes another problem that i am told gm is working on is the ISC is slow to react. GMs working on a solution but you will probably fix it yourself before the get a fix for it.

Theres not a lot of technical help out there for the ramjet. Mine has 1800 miles and still wont rev over 4000 rpm. Ive struggled with my dealer they have not been able to give me much help. They decided the codes meant it had a bad ecm. They gave me a new computer and told me that it had to be ran 5 hours until it would rev up. It seems to start and idle better with the new ecm but still cut out at 4000.

The most headway i made with it was with help from a tech that applied general fuel injection trouble shooting principles to my car. With his help i was able to clear all the codes but still no rev up.

I got some bum info from a couple reputable sources so im leary anymore. Its a shame my dealer doesnt even have a scanner for the ramjets. I bought my own it should be here tomm so ill update you if i find out whats up.

Good Luck John

[jeb conde]

john your right im sick of dealers even speed shops selling products and not knowing anything about them or where to get them serviced i bought the ram jet because i thought better mileage better response better cold start up less trouble than tweeking a carb set up every other day but now im starting to reget the purchace and wish i would have bought the carbed 385 fast burn im almost at the point where im gonna sell the car and get a newer car maybe 2003 cobra but i really enjoy the lines of my car(69 chevelle) but wacthing it set in my garage is making me sick ive sold my 97 trans am to get this car going but noone here in houston is very helpful i get alot of the "we only work on ls1's" or "we only work on 4.6's"so if i dont get this car running soon i'll be rollin in a 4.6 thanks for the help dont mean to complain so much but im at the end of this
to gm if you put a crate motor out make sure atleast 1 of your mechanics knows how to work on them