New to the site! Need some help with my newest toy. 88 Gt 5 spd Flat throttle response any gear, new plugs and motorsports wires cleaned IAC with carb cleaner though probably should have let it soak. Car was sitting for quite a while 2 plus years I changed fuel pump, filter and strainer added fuel injection cleaner and drygas and fresh premium It seems to rev OK without a load on it ie: neutral but will pop occasiionally on the road it wants to bog severely if pedal is over 1/2 way or motor is not allowed to rev slowly under lite throttle. Couldl use some suggestion Help! Sorry about the long first post
It's really hard to diagnos stuff like this because there are so many variables that could be the problem.
First thing i'd check is the cap/rotor if you haven't already.
I just want to make sure i understand. Does it rev up to redline if you rev it slowly? or does it seem to bog at a certain place you put the throttle at?
The reason i ask is because if it is always bogging when you put the throttle pedal to a certain place you may want to look at the TPS (throttle position sensor). We have a second under "Maintenance" that shows how to check your tps voltage. You'd want to do that test and while you are at it see if the voltage climbs steadily to around 5v while you open the throttle.
Here are a couple of other things you might want to look into.....(i'm just thinking out loud).... When i got my car it had a bad coil in it and would do exactly what you are experiencing. The car would seem to rev ok and have good power but at 3500/4000 rpms it would fall flat on its face and act almost like there was a rev limiter there, popping and bogging. I happened to have another coil laying around, swapped it and that fixed the problem.
Another thing. Do you know if your car has ever been converted to mass air? 88's (except CA cars i think) were originally speed density equipped, but if its been converted over to mass air (pretty common) then you'd definately want to look into cleaning the wires on the MAF. (Mass Air Flow meter)
If you need anymore help with anything i've just said (i know some of it was quickly babbled...LOL) dont hesitate to ask.
Sounds good except that i believe the iac being the problem is highly unlikely. That (the iac) is really just a small motor with a valve attached to it that controls how much air enters the engine while at idle so it should hurt upper rpm performance even if it completely stopped working.
Good luck finding the problem, and let us know when you do.
I had the same prob. with my '88 speed density LX. Way lean at part throttle, O.K. wide open.
My prob. was a leaky fuel injector that fooled the oxygen sensor into thinking it was running too rich, so the computer pulled all the fuel out. At W.O.T the oxygen sensors are ignored, and a standard fuel and timing map is used that allowed my car to to rip.
regards, 88 RX
****, see thats why i usually say that you never know what the problem is because it could be so many thinks on a fuel injected car. Sometimes the problem is so simple, other times its impossible to find.