1990 240sx missing, backfiring, no power!

[rschwalbe]

1990 240SX when I step on the gas it feels like I am short a couple sylanders, I get misfires and backfires and have no power what-so-ever. I have replaced plugs, plug wires, distributor cap and rotor. I then took it to my mechanic who thought it sounded like a MAF, AIV, or EGR valve problem and he tested all that and they weren't the problem so he recommended I take it to Nissan. Nissan states that since my mechanic drilled a hole in the EGR valve they won't diagnose any further until the EGR is replaced!!

I need to know if anyone has any ideas and have an urgent need for this as I am supposed to be leaving next Friday for a new job and need to drive this thing 800 miles to get there!

Any ideas at all would be greatly appreciated as quickly as possible! My mechanic also cleaned all of the electronic connectors of the green deposits to eliminate that!!

Thanks!

[rschwalbe]

P.S.

Also, no codes from the ECU and he also tested my fuel system!

[Touchdown038]

Why did your mechanic drill a hole in the EGR valve?

Get a timing light and check timing, also check for spark and do a compression test.

[rschwalbe]

He drilled a hole because the EGR valve was stuck open--he did the timing and compression test.

[NISTECH]

try wiggling the harness along the valve cover while its running and see if it effects the idle... may have a broken ground in the harness. just shift it forward and back a little. it wont take much to effect the idle quality.

[rschwalbe]

Mechanic checked all that already as did I.

[NISTECH]

the back fire you hear where is it coming from the intake or the exhuast?

[rschwalbe]

exhuast

[NISTECH]

do a leak down test on your injectors,see if one or more are not holding back fuel. also check your coolant temp sensor connectoion make sure its not corroded. it sounds like your building up fuel in the exhuast. also hook up a vaccum gauge place it so you can see it when accelerating at steady speeds does the vaccum return to within 5in of idle? if it is much lower perhaps you have a restricted exhuast system?