Hello All,
Just looking for some direction.
My son has a 95 Z24 with a Quad 4. I'm battling an "underload" miss and thought maybe someone else out there has experienced the same thing and can give me some info. I replaced the O2 sensor last winter so I'm pretty sure that is fine. He changed the plugs a few days ago and I plan on putting a new set of wires on it tonight. I figured it wouldn't hurt to try a simple tune up first to see if we can't solve it that way. Are there any other sensors that could be causing this proble? It's just odd because it only does it under load or heavy acceleration. Sitting in park you can tach the engine up to about 4500 without any miss. Once you get to 4500 it starts to miss and the tach bounce.
I can take it in and have it scoped but I thought I'd give it one more shot to solve tonight.
Any suggestions?
Thanks
Scott
You don't have wire, you have boots. Change them and you may see a difference.
Gilles
2.3 Ho
maybe you have an ingnition module breaking down when its hot and under load....just a thought......check the coil resistance also.....
I would still change the boots first. They are cheap and it's always good to change them. I've had so many problem with those boots. Hesitation, sputtering, lack of power, not being able to rev over 2500rpm, ...
Gilles
2.3 Ho
Is the check engine light coming on?
Some things to consider:
Fuel filter. When has it been changed last?
Vacuum leaks (especially that hose going into throttlebody from MAP sensor)
USE AC DELCO PLATINUMS. If Bosch were used, take them out. The car will run poorly after a few weeks.
Not nearly enough info, but if I had to guess, it could be fuel delivery problem, secondly, maybe a coil.
knock sensor possibly I know a friend with a 95 that had the same problem a real loss in top end power replaced the knock sensor and it was fine again
1989 Turbo Trans Am #82, 2007 Cobalt SS G85
Thanks for the info guys.
I changed the boots this weekend and it instantly ran better however, he took it on a short trip Saturday and after about 45 minutes of highway driving it started acting up again under load. I'm thinking at this point it's probably the coil pack or ignition module. I'm leaning towards the coil at this point thinking it's breaking down once it heats up.
The fuel filter has recently been changed. I tried to rule out fuel delivery early on.
Thanks again for the info, thought we had it with the boots but I guess we'll have to dig a little deeper.
Scott
Don't buy a new IDI nor coil. Go in a junk yard and buy a complete IDI cover with all the goodies(coil, boots, coil housing, ignition module)
Gilles
2.3 Ho
That's exactly what I did. I called the local bone yard this morning and picked one up that only had 24K miles on it for $70.00. I thought that was fair enough.
Scott
