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Old 10-11-2004, 05:34 PM   #1
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Default Loss of power, wierd idle issues and more!

Some of these questions may have been asked before but I figured I would put them all in one post anyway.

1987 SFI

Now about 1 year ago the car had very good power and idled fine. One Idaho winter later I am stuck with a few issues. Last February we got an 18" snow storm in a short period of time, a record amount of snow for this area and along with that there were a lot of ice pot holes. At one point the car bottomed out on the Cat and I had it replaced with a high flow as it was completely smashed.

Right after I had the cat put on this car flew (for a 1.5 ton car) Then it lost a lot of power. I pretty much let it slide as it still ran and drove fine, but it was no longer fun to drive. This was at the same time I aquired the 89 bonnie and it blew me away with how much that extra 10hp did


I very recently replaced as preventive maintenance only:
Spark Plugs
Spark Plug
Water Pump
Radiator
Oxygen Sensor
PCV Valve
Every vacuum hose at the throttle body and pcv
I cleaned the throttle body RELIGIOUSLY and put in a brand new MAF sensor 2 days ago.
Air filter replaced last week
Tested TPS voltage and it is around 0.4 at closed throttle after I adjusted it.

The engine now runs VERY smooth but did not gain any power.

Also when I step on it (WOT) at low speeds and then cut back it will flash a 32 which is an EGR related item. but when I step on it again, I am guesing reach 3200 the light goes off.

The main other problem is that when the car is cold it sometimes does not go up to high rpm and just idles at 800 rpm and dies like this morning when it was 32*

The final issue is the windows are pissing me off, I have used sicone, grease and WD-40 in the tracks and the main window motor track and they still slow back down in a few weeks.

I know nearly nothing of fuel injection cars and am stumped. So before I go out and buy a new iac,tps,egr,egr solenoid, and god knows what else, a few questions:

What are the main things that make these engines loose power without flashing a code?

What is the component that tells the PCM what rpm to run the engine at when it is cold or the part that warms it up?

How much power will you loose when there are emissions problems (excluding a bad cat) on these cars?

What do you use to lubricate your window tracks (outside edge) and that main in door window pusher track? Grease? WD-40? Silicone?
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Old 10-11-2004, 05:45 PM   #2
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The cold.. that is the crank sensor, the cam sensor tells the ECU, the crank tells the ICM..


-justin
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Old 10-11-2004, 06:01 PM   #3
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what keeps an engine from making all the power. Well, it could be the engine is out of tune. Coil could be bad, ICM could be bad, many things.. out of tune, clogged air filter, the list goes on.


-justin
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Old 10-11-2004, 07:18 PM   #4
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Ran great for two days almost sounds like a block learn (air/fuel map) that is rong. Try this. Disconnect the battery, wait 30 second- 1 minute, reconnect. This will clear all learned values. See how it runs. If a major improvement then would be time for a recording scan tool.

Another possibility is a munged up O2 sensor. Some go bad almost instantly. Can cause an engine to drop out of closed loop but error code will generally be 43 or 44 (OTOH I had one sensor that would quit above 70 mph. No error code. Only caught with a scan tool.

Bad cold idle I would look for a gunked up Idle Air Controller that is sticking. May get better when warmed up and gunl softens.
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Old 10-12-2004, 01:31 AM   #5
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Quote:
Originally Posted by opensourceguy
what keeps an engine from making all the power. Well, it could be the engine is out of tune. Coil could be bad, ICM could be bad, many things.. out of tune, clogged air filter, the list goes on.

-justin
Quote:
I very recently replaced:
Spark Plugs
Spark Plug
Water Pump
Radiator
Oxygen Sensor
PCV Valve
Every vacuum hose at the throttle body and pcv
I cleaned the throttle body RELIGIOUSLY and put in a brand new MAF sensor 2 days ago.
Air filter replaced last week
Tested TPS voltage and it is around 0.4 at closed throttle after I adjusted it.
You mentioned the coils could be bad. I replaced the coil pack about 6 months ago with a NAPA one.

What is an ICM?



Quote:
Ran great for two days almost sounds like a block learn (air/fuel map) that is rong. Try this. Disconnect the battery, wait 30 second- 1 minute, reconnect. This will clear all learned values. See how it runs. If a major improvement then would be time for a recording scan tool.
Yes I have done this multiple times just to clear the codes to see if it was in a limp home mode or something.

Also when you say scan tool are you refering to a Auto-Xray type setup?

I do know it is givnig a 32 when you punch the gas (decently) and then let off and the code will pop up, Sometimes if you hit the gas it will go back out. And yes I have checked it many times at it just says 32.

I have 2 suspected items based on what I have read in the chiltons/hayes/here/other forums:

- TPS not giving a good voltage at wot
- somehow screwed up EGR Solenoid or Valve

I should also mention the car is still getting 25mpg on the highway instead of 29/30 as it got before which is why I did most of the above items, but it made no difference whatso ever on mpg'*.

thanks for all the help so far

- Hans
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Old 10-12-2004, 08:51 AM   #6
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I know you replaced the coils, I was just shooting out suggestions. The ICM is what sits under the coils, but above the mounting bracket. These can fail, and so can the coil pack.. the magnavox ignition system is not very good.. at all.

What TPS voltage are you seeing at WOT? you should be seeing 4.35 volts [correct me if I am wrong here guys].

Scan tool... well since we have the good ol' days of OBD 1 systems, this doesn't mean stuff for the OBD2.. this is a little different. But when I hear scan tool for our cars, I think of the homemade one.. but Padgett has a different one I believe.


-justin
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Old 10-12-2004, 10:09 AM   #7
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TPS should be over 4.2v at WOT. Should also be .38v-.42v at idle though the computer seems to "learn" where is is.

As to scan tools, the most cost effective I've found is the OTC 2000, can usually find with right cable (GM) and cartridge (GM or Pathfinder 3in1 of the right year - I have a 1989 cartrige that works well in our '90 if you lie to the configuration, the code "C" datastream seems the same from 1989-on. Not sure about 1987-88. These can be found in good shape for $25-$50 (1993 3in1 cartridge is the most valuable and the last update available). There is a PC/Cable connection that is rarely found but details on how to build one are on. The OTC 2000 was replaced by the 4000 and is now considered obsolete by the trade hence the low prices.

For the ability to record frames with a PC or notebook for study later, the current price if you want to buy a package is either $80 if you put up with begware or $110 for a fully registered package. What you need is the ALDU1 and CABL1 from Craig Moates ( www.moates.net ) that plugs into a USB port and the TunerProRT software from Mark Mansur ( http://www.supportfitness.com/mark/tunerpro/ ). You also need the 1228253_v03 definition file (on Craig'* site) for the "C" 3800. This requires some configuration.

The next step up is the Rinda DIACOM Software and cable which connects to a parallel port. Site is www.rinda.com but am not certain how long this will be avaiable as development stopped when OBDII came out.
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