I am having serious problems with the car at idle in drive (a bit rough, and it almost stalls, and occasionally does), and a lack of power at WOT. At idle in drive, it will start to idle rough after you come to a stop, and sit for about 8 - 10 seconds. It has better acceleration when you give it 1/4 to 1/2 throttle, than at WOT, and in addition, the valves make noise around 3k RPM, and randomly after that, and consistent noise when trans shifts. It also pops on deceleration, and lets out way too much fuel at WOT. Everything appears to be in order, and I have heard tales of woe with the "old ECM". It seems like a have a fuel problem, but I need to get to the bottom of what is causing it. Any help would be greatly appreciated.

 

carbed I take it? I had this issue (sort of) on my '87 computer controlled carb. and replaced the ignition module, which helped, but could never pinpoint the problem. Is this all the time or only after it is warm?

 

This is a Tuned Port Injection model, and it only idles rough in open loop. It is one of probably only a handful like it.

 

Couple more questions...for others to help here too as I have a limited amount of ideas on this. Has the car just started doing this or has it been this way since you bought it? Gradually getting worse? I would check the timing, TPS, and IAC counts to start. If you have a multimeter and timing light, shouldnt take too long. That way the basic stuff is out of the way.

 

hey there fellow 85 tpi owner here. i would definatley check out what was stated earlier with the tps, timing, fuel pressure and iac. mine ran rough like this when i first came into ownership of the car-tune up fixed it though. i would suggest cleaning the iac passages and the iac itself, its very easy and improved idle quite a bit on my car. if you dont know how to do any of this stuff just do a search, tons of info, and all of it is very easy to do.
...however, i have noticed that 85 tpi's due tend to idle a little on the rough side. i figure this is due to the stoopid ecm and the l-98 cam they got. however this assumes you engine and ecm are original.

 

Tell us more . . .

 

mine is doing almost the same thing but i think it's a fuel issue like fuel filter... i am also an 85 tpi owner...

 

As of tonight, I no longer receive ANY trouble codes, and it idles like a dream, no real off line power, BUT if you ease into it, the car cruises like a dream. I ripped around the block a few times tonight, (late,late,late show, no traffic on the old country "back roads"). I think I finally lost the old PROM, it seems like the car is running on "default", and I think I might blow $75 on a new stock one, it looks like the old one was as old as the car. Anyone care to cast a dissenting opinion?

 

The IAC is brand new, and so are most of the other sensors, except the knock sensor, the only one that hasn't been replaced in addition to that is the fan switch on the right side of the block. The MAF checks out on the multi-meter and scan tool as functional, fortunately or unfortunately. I will double check the fuel pressure this weekend, but for reference, it has a brand new filter and pump inside of 20,000 miles. NO mention of the regulator from the previous owner...
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Greg, if yours isn't black with a webbed headrest interior, and the leftover anniversary rims, you're not one of the few...

 

Well, if the sensors are new, the only one you still need to check is the TPS. It can be moved and therefore needs to be set at a certain voltage at closed vs WOT...voltage readings then tells the computer what to do in regards to fuel delivery, timing, etc.

 

TPS and minimum idle air are set properly, ignition on IAC disconnected, the whole 9...

 

were is the timing set at and what did you disconnect to set it. also do a check on your coil and your ignition module.

 

- I guess I should point out something. It looks like you were implying there was something different about your TPI. Of what relevance to your problems are appearance items? It looked like some perceived rarity about your car was at issue.

Lost the PROM, huh? Yea, that's a big problem. You're supposed to grease them every 3K miles.

 

for reference, the TPS, IAC, are functioning properly. Minimum idle air is set, and timing is at 6 degrees BTDC. I don't even get a code 12 anymore, but the scan tool reads all input, and the car runs as priorly mentioned. This would mean that the MEMCAL is functional, but I have no CPU or learning function. I am going to order a stock chip, and see how it does, it needs to go in for emissions inspection anyway... PS, Greg, I didn't realize you couldn't tell the fuel setup, the specs to know what is under the hood are right in the BIO. Code "F"