84 Turbo hot air driveabiltiy

[sosuzguy]

Howdy
Well I found out yea I had a rounded out lobe on the cam shaft and spun #1 connecting rod bearing and stacked a thrust bearing. Got it all rebuilt and put back in the car. Everything works okay but two things. Right after taking off from cold start when you stop at light it idles real bad till warmed up or you give it more throttle. --- Second thing is while crusing highway speeds it feels like it's lightly surging some or a light cut out. Any ideas? I'm thinking the idle needs to be turned up for the idle prob as once it's warmed up no idling problem at all. Thanks

 

[Johngregston26]

I HAD AN ISSUE SIMILAR TO THAT...DOES IT THROW AN SES LIGHT??..MAY BE LOOSE HOTWIRE TOUCHING SOMEWHERE..IT ACTUALLY STARTED CUTTING OUT BAD BEFORE I FOUND IT sorry for the caps...i see u are close to garland id like to pick your brain ive had an 85 for a month now reading my tail off wanna see someone elses ideas and knowledge

 

[sosuzguy]

I've looked all over the engine compartment, can't see anything not plugged in. I'll send you a PM with my cell number to call.

Anyone else? I'm still having problems. Thanks

 

[turbonut85]

Check your plug wires and plugs. Make sure the grounds for the main engine harness are tight...(under the A/C compressor) Got a scantool??

 

[sosuzguy]

Plugs and wires are all good and grounds. No scan tool, I didn't think they would work on an 84 hot air. I do have an OTC 2000 scanner but the info the 84/85 ECMS send is very limited. I'd love to upgrade this ECM to an 86/87 so it would be easier to diagnose.

 

[BRAD_PADGETT]

Howdy
Well I found out yea I had a rounded out lobe on the cam shaft and spun #1 connecting rod bearing and stacked a thrust bearing. Got it all rebuilt and put back in the car. Everything works okay but two things. Right after taking off from cold start when you stop at light it idles real bad till warmed up or you give it more throttle. --- Second thing is while crusing highway speeds it feels like it's lightly surging some or a light cut out. Any ideas? I'm thinking the idle needs to be turned up for the idle prob as once it's warmed up no idling problem at all. Thanks

The idle cannot be adjusted since it is controlled by the ECM. The best way is to upgrade the ECM, MAF, and ignition to the 86/87 setup. Bad idle means alot of things. These upgrades are not cheap either so do your homework. Brad

 

[sosuzguy]

Yes the BASE idle can be adjusted on these cars by disconnecting the IAC while the plunger is extended and opening the trottle plate a bit more. I've done my homework and also have to add a air temp sensor to switch it over. As it stands nothing checks out as being faulty. I've been messing with this car and so has 3 other reputible mechanics who know these cars in the Dallas area. The way I see it the only way to find out exactly what componet is not working properly is to upgrade so the data stream has more info to look at and find what's not working correctly.

 

[BRAD_PADGETT]

Yes the BASE idle can be adjusted on these cars by disconnecting the IAC while the plunger is extended and opening the trottle plate a bit more. I've done my homework and also have to add a air temp sensor to switch it over. As it stands nothing checks out as being faulty. I've been messing with this car and so has 3 other reputible mechanics who know these cars in the Dallas area. The way I see it the only way to find out exactly what componet is not working properly is to upgrade so the data stream has more info to look at and find what's not working correctly.

Like I said-The idle is controlled by the computer. The IDLE air contol valve is only one of many computer inputs. It by itself does not control idle. My suggestion is upgrade and do more homework than your reputable mechanics. Brad

 

[fmster]

I would check for a vacum leak and spray clean the IAC and the throtle body part.

 

[turbonut85]

I agree with Brad. Research some more on this before you start "adjusting" things...You do not have to add the IAT sensor...merely have it turned off on the chip...that's assuming you will be getting a new chip burned for your setup...don't try to use the stock 84-85 chip or a stock 86-87 chip, as they won't be the ideal settings for the car.

 

[sosuzguy]

I would check for a vacum leak and spray clean the IAC and the throtle body part.

Thanks - no vacuum leaks and IAC passeng ways and throttle body are clean!

 

[youngstr]

If you have a Scanmaster, check the voltage on the TPS as you move the accelerator around and especially when you hit that area in the pedal where you cruise.... you're looking for a voltage dropoff or dead spot in the TPS, had this happen before like it wore in one spot from cruising highway miles. You can also check this with a multi meter at the TPS sensor, you'll need a helper to do it that way. As far as the idle, if you changed anything on that rebuild from stock spec the warmup data is gonna not work as well. I would suggest as someone else did, that a different chip might be the solution, as opposed to just adjusting the idle screw, reason I say this is , adusting the idle up for when its cold will mean after its warmed up you're gonna idle even faster, because once it warms up the screw doesn't adjust ....where as the computer would adjust, so I'd say try a different chip and if you have the extra scratch layin around go for the 87 ingition and ecm upgrade, did that on mine and it runs smoother.

 

[novaderrik]

sounds an awful lot like a vacuum leak to me.. there's about a thousand places that can leak on these cars, so look everything over.. it might be as simple as retorquing the intake manifold bolts.