84 engine miss

Reply Subscribe

Thread Tools

Search this Thread

Jun 30, 2003 | 11:13 PM

sumoboy

Thread Starter

Racer

Joined: Feb 2003

Posts: 415

Likes: 0

From: Joppa Md

84 engine miss

My brother in law has a 84 X-fire and he said that after about 5min of driving the engine seems to be running off 7cyl.He comes to a light and stops and it just starts missing. It stays that way till he shuts it down for awhile. If he keeps running it never clears up. I haven't looked at it yet but any answers or clues? :confused:

Jul 2, 2003 | 10:17 AM

drpepperkid

Instructor

Joined: Apr 2003

Posts: 116

Likes: 0

From: Kinston NC

Re: 84 engine miss (sumoboy)

I've got the same exact problem. I haven't figured it out, but I'm not going to either, because I'm deleting most of the emissions crap and switching from cross fire to carb along with a comp cam and a few other goodies. As for the miss, like I said I don't know, but I'd imagine it's one of the following
(1)leaking (loose) intake/TB's, (2)idle air control valve or other sensor bad, (3) or its bad plug wires. Anyway, I wish you and your brother in law the best of luck with it.

Jul 2, 2003 | 11:31 AM

Saisling

Burning Brakes

Joined: Apr 2003

Posts: 783

Likes: 2

From: Wake Forest, NC

St. Jude Donor '05

Re: 84 engine miss (sumoboy)

Start witht he easy stuff... How many miles has it been since the car has had a good tune-up? I'd start with plugs and wires/cap and rotor if it needs them and see if it gets better. How does it start? Any trouble there? If it is hard starting, hesitating on acceleration and missing, those are all signs of the fuel pump on it's way out...

Jul 2, 2003 | 01:30 PM

GiDvEtTe84

Drifting

Joined: Apr 2000

Posts: 1,915

Likes: 0

From: Maurice, LA

Re: 84 engine miss

Could be ignition:
Wires, plugs, cap, rotor, coil, module......

Could be fuel:
Pump, pump screen, filter..........

Check out http://www.crossfire.webhop.net

Jul 2, 2003 | 09:26 PM

sumoboy

Thread Starter

Racer

Joined: Feb 2003

Posts: 415

Likes: 0

From: Joppa Md

Re: 84 engine miss (Saisling)

I was over there yesterday to work on the A/C and it starts and runs fine then about 5 min it just sat there and the miss started. I noticed the flaps on the air cleaner housing were shut so I held them both open and it started tro smooth out gradually. I unhooked the vacuum lines to it from the sensor and it seemed fine. He's going to drive it around tomorrow and let me know if that might have been the problem. I told him it might have been starving for air. :thumbs:

Jul 2, 2003 | 10:01 PM

Netnarc2

Racer

Joined: Feb 2002

Posts: 424

Likes: 0

From: Anaheim Ca

Re: 84 engine miss (sumoboy)

Just an idea. Check the distributor cap. Maybe it's got a crack in it and when the engine is cold, the distributor cap is cold. When the engine heats up, the ditributor cap also heats up, which might open the crack a little, causing the missfire. They still have rotors in the '84 distributor? Crack widens, rotor misses contact?

[Modified by Netnarc2, 3:02 AM 7/3/2003]

Jul 2, 2003 | 10:31 PM

jefft84

Racer

Joined: Jul 2002

Posts: 412

Likes: 0

From: corvallis or

Re: 84 engine miss (sumoboy)

With in 3-5 minutes the computer goes into closed loop and the computer needs input from the oxygen sensor to correct fuel mixture. If the sensor is reading out of range your computer will make the car run rich or lean, from your flap discovery it seems to be running rich.

Jul 3, 2003 | 06:33 PM

american-muscle

Intermediate

Joined: Jun 2003

Posts: 28

Likes: 0

From: Cary NC

Re: 84 engine miss

Hey, my car is having the same problem with the hesitation and the miss fireing. I was wounding when this happened did ur check engine light come on?? i have so far done plugs wires and fuel filter