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85 Engine project: The break-in phase

maxrevs85

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Dec 17, 2001
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709
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Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
Thanks Chris, definitly food for thought .
My scanner did tell me my tps was too low. The biggest problem is the 85 computor. I believe its very limited on info and is very slow . I havent driven it with the scanner attached yet . Tomorrow I hope to get some info with it. The co-pilot is ready to go. :)

Ken, the new title is perfect.

:upthumbs
 

maxrevs85

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Dec 17, 2001
Messages
709
Location
Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
Update on the continuing tuning phase. Still having a high idle problem . NO vacumm leaks!! 25 hg vac @1500 rpm. talked with Jim at TPIS again . Told him that when setting base timing and advancing , the idle will go up with the amount of advance added. If i set it at 6* advanced ,and then reset and reconnect the EST the idle climbs to 1800 and shows about 38* advance. I dial the initial timing back to 2* retarded and 850 rpm and EST brought it to 31* total advance @ 1400 rpm . At this time I'm driving the car with the EST disconnected and the stock chip installed . Sent the other chip back for some adjustments. The car is good to cruise but not real responsive . At least I can drive it though. :)
On positive note though , when everything was hooked up properly and even with the high idle and 34* advanced , she is bad a** fast and kinda scarey. MAN WHAT FUN. you gotta have a grip on her in 1st and 2nd, :eek
 

maxrevs85

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Messages
709
Location
Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
I thought I'd mention some findings on some of my concerns when putting this project together.
One concern was if I was going to have a problem with the stock cooling system. The system is the heavy duty option and the radiator is in excellent condition , I'm thinking its been replaced by the previous owner or just very maintained. Ok, I'm using a 180 degree thermostat and my prom is programed to turn the fans on at 205, which it does . The temps here have been in the high 80's and mid 90's and very humid. While cruising at the 55 to 70 mph the temp is at about 183 to 187 and around town with a little hotdogging thrown in , it has'nt gone above 208. I really believe that the 180 thermo is the way to go and that the 160 is not.
Another concern was that the poly bushings might produce a harsh ride on an already stiff platform.To the contrary. They have improved the stability AND traction to where it feels much more prodictable and consiquently a better ride. I replaced the shocks with the Bilstiens from Mid Amer as a set that were said to be the replacements for stock . I'm quite satisfied with the results. Better tires would be another improvement also . The steering rack is new too and is the 2 turns lock to lock unit. Love it
More feedback to come as the results come in :)
 

maxrevs85

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Joined
Dec 17, 2001
Messages
709
Location
Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
Chris, you are correct about the rich fuel condition . I can live with the smell .Perfomance mods always bring on the race car odors and i love it. My fuel pressure is at about 42 psi at this time and the TPS is .62. When i get the other bugs out of it I will be doing what you mensioned with the tuning process.
Ken , the way my car runs and I said it is a little scarey, I cant imagine tacking on another 100 HP. Oh wait , I could imagine it . Never enough. Man you are going be Geeked !! What a ride. :L
 

Ken

Gone but not forgotten
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8,236
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Hermosa Beach, CA
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1987 Z51 Silver Coupe
maxrevs85 said:
One concern was if I was going to have a problem with the stock cooling system.

One thing I have been able to tell about mine Dave, is the fact that it runs as cool as any car I've ever had now that I replaced my radiator with a Be Cool unit and a 180° thermostat, and it runs right in the high nineties even when sitting for lengthy traffic delays. It keeps cool even when I'm sitting there in traffic while in the "limp home" mode. That's at least one thing I got right with this project at least. :L

_ken :w
 

maxrevs85

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Messages
709
Location
Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
Time again for another segment of "I LOVE MY CORVETTE".......
Yesterday I went for my first away from home more than ten miles trip. Everthing was going well . I set the cruise at 78 mph at about 2100 rpm and was rolling merrily along . Well I decided I needed to step it up alittle so I CANNED IT. Went to 120 in a heartbeat. I didnt want a ticket so I drop her back down to cruise speed and check out the gages and I noticed the temp gage was moving upwards and at a fast rate. I thought oh no I hurt it .After pulling over and shutting it down i popped the hood and saw the belt was totaly shredded. I thought that was odd being a new belt. On further investigation . I saw the tension pulley had spit all it bearings out and was looking bad. I was about 30 miles from home . A friend of mine was with me also. So, I called home for the number of the parts store in my town to get the parts and have the wife deliver them .This was about noon. They had the belt but no pulley and it wouldnt be available till 2:00. Ok, so , I was only a few miles from another town so I ask them if they could call the car quest store for me. They said it wasnt in their district. I said well give me the number, UHH, I dont have it came the reply.....now I'm getting :mad ...I call info and get the number at the store up the road . I"m on the freeway BTW. They have the parts and kiddingly I said "Do you deliver"? They said where are you ? I told them and they came out with the parts and the needed tools . They got a tip ,the car got fixed and I was on my way. Just so happens they said ,these parts are for a Vette , we gotta help them. :) But anyways , the car ran great it handeled beautifully, and I loved the trip. It was only about 200 mile round trip. The parts store in my town I do abunch of businees with for years and know all the people . I'm not too happy with them.
 

maxrevs85

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Dec 17, 2001
Messages
709
Location
Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
Its been awhile since posting on my engine project or breakin phase. As time has elapsed and more miles were put on I noticed I was getting a little lifter noise and when hot they got even noisier. I thought maybe I was having an oiling problem . I then noticed the oil was smelling pretty fuel rich. After changing oil it quieted down . I readjusted the roller rockers and that helped too. I started noticing a little more fuel rich smell also. I made adjustments to fuel pressure and to the throttle body Which seemed to help. I was still having some high idle woes too. So, I decided to change to my stock 48mm TB and this helped. But, evrything went to hell after that . A couple days later setting in traffic on the way to work I was surrounded with smoke and a rough running car . I limped the last mile to work and shut it down. After work I reset the putor and started it up and the same smoke. Fuel and oil was running out of the exhaust. I had it flat bedded home, drained the fuel , I mean oil. I either had a fuel reg diaphram go or a stuck injector. I'm sure its a stuck injector. The problem is that now I'm going to have to pull the motor and have the block honed and install new rings and bearings. I talked to Tpis and I'm sending my injectors to them to check out. They are Accels, 24lb. I might end up swaping them out for the bosch. Also I believe I'm going to go to the 52mm TB. They have increased the cfm's as of late. So, the engine breakin goes back to the build stage once again. I tell ya , I was almost ready to put my still in the box ,new 830 cfm holly 4150 on and say the hell with the TPI. But I'm not ready to throw in the towel yet. When i get it together again I think I'll take to Florida where the Killer vettes are built,get it tuned right. :L
 

Ken

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Messages
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1987 Z51 Silver Coupe
maxrevs85 said:
But I'm not ready to throw in the towel yet. When i get it together again I think I'll take to Florida where the Killer vettes are built,get it tuned right.

You certainly couldn't go to a better person Dave! My hat is off to Chris for all his help when I was there. :upthumbs

_ken :w
 

maxrevs85

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Joined
Dec 17, 2001
Messages
709
Location
Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
I have to agree on that point.
So whats going on with your project ? Where are you at with it and whats next? My putor has been in repair for a week . Just got it back. Not that anyone missed me.:D
 

69MyWay

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Jul 3, 2001
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4,364
Location
Auburndale, Florida
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1969 Killer Shark
maxrevs85 said:
I think I'll take to Florida where the Killer vettes are built,get it tuned right. :L

I wish I had that kind of skill and ability. Like you, I just keep plugging away, trial and error.

Wow! A serious bad injector or two! I guess the first clue was the out of control idle, then the fuel stink, then the...well, flatbed ride home.

I have shade tree bench tested injectors before. I would think you could have either a bad injector or two, and or maybe a short in the wire harness that is allowing them all to open up at one time too long. That would be my two guesses.

Keep us posted on the progress.

I would think you don't really have to pull the engine back open for this. If it were me, I would take a chance on replacing the injectors, checking the wiring, and going back together with high quality oil. It does not sound like you ran it for any extended time after the huge cloud developed. Remember, that it only takes a small amount of oil on TOP of the piston to create a huge cloud of smoke. Chances are, it is not as bad as it seems.

Chris
 

maxrevs85

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Dec 17, 2001
Messages
709
Location
Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
The flat bed ride for sure. I do agree with what you are saying about not pulling the engine . But, I think its been going on longer then I originally thought . I was getting some smoking at WOT runs and it wasnt tire smoke . The heavy fuel situation was so bad it was running fuel and oil out of the tailpipes. The header to Y-pipe connector was leaking fuel an oil too. I guess piece of mind makes me want to pull it. We'll see.
On the 85's dont all the injectorsfire all the time? wouldnt think you would have the probem with new ones , Ken had the same deal with one of his.
Trial and error for sure. Too much error though.:(
 

69MyWay

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Auburndale, Florida
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1969 Killer Shark
maxrevs85 said:
The flat bed ride for sure. I do agree with what you are saying about not pulling the engine . But, I think its been going on longer then I originally thought . I was getting some smoking at WOT runs and it wasnt tire smoke . The heavy fuel situation was so bad it was running fuel and oil out of the tailpipes. The header to Y-pipe connector was leaking fuel an oil too. I guess piece of mind makes me want to pull it. We'll see.
On the 85's dont all the injectorsfire all the time? wouldnt think you would have the probem with new ones , Ken had the same deal with one of his.
Trial and error for sure. Too much error though.:(

I hear what you are saying. Your engine is new enough, and you have built it with performance in mind that I would not be shocked to know it is puffing smoke on WOT runs (until it is full broken in). The wet stuff in the PIPE is really bad, but, my thought is that you are looking more at a combo of moisture, fuel, and carbon material being washed out of the PIPE. If you were pumping straight oil out of there you would have a problem, no doubt. Maybe a quick compression test before you get too deep, and a quick reinstall of the stock injectors as well for a test of the overall engine components.


BTW, I destroyed the clutch in my 90. It is sitting up on jackstands in the garage as I wait for the new disc, and I contimplate some other mods (like 3.7 rear gears). So I am with you on the error part. It gets very old after a while. Just look how long it took me to get Killer road worther, and it STILL has a minor oil leak on the driver valve cover. It never ends, but we stay at it in the hopes of defeating the beast.
 

69MyWay

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1969 Killer Shark
One more thing....

Back in 96 I had a 383 in my 85 Vette. It was STRONG. One day on the way to work it started to idle funny (high). I went down the road about 2 miles and stopped at a light. The high idle became irratic, then I had to work the throttle to keep it running (in traffic). Here came the cloud. There was fuel/oil smoke everywhere out my tail pipes. I worked the throttle and brake to keep it running and limped it to the office. There in the parking lot I looked like a mosquito fogger.

Long story short, the MAF had failed and was doing so little by little. It went full on rich and was dumping huge amounts of fuel down the shooter. I was dripping on the tail pipes and stinking BAD. I took a company car to Napa on my lunch break, popped a new MAF, and made it home with zero defects. My oil smelled like fuel though, so I changed it out the next day. Never had another problem.

Any chance you have a hit and miss MAF?

Oh, it did not set a code right away either, and when it did set, it set several codes at once due to the overall terrible mixture situation of the engine in general.
 

maxrevs85

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Messages
709
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Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
You've hit on some good points Chris. The mosquito fog you mensioned is exactly what it was . Couldnt see around the car at all:L The MAF thing makes me wonder. When I left home for work that morn, 20mile trek, I got down the road a ways and it started to miss like a fouled plug or an injector skipping. Then it would be fine . When I came to a lite it would start again. It got increasingly worse. Somthing was causing it to poor fuel in. I think aninjector was flooding a cylinder. But then again as you said it could be the MAF failing. I will take your suggest and put the old injectors in and new oil. Ive been wanting to start it again anyway. Boy is it going to smoke for a bit :eek....hey, thats too bad about your clutch deal.....like they say " if ya wanna play ,ya gotta pay" .......But of coarse up here it was time to put it away for the winter anyway .
Btw ,to top it off , Tpis doesnt have the software for the 85's right now . They had some probs and lost the program. Sooo, I'm out of luck untill they get it .( for the proms that is).
My other considered project is , at this time anyway, is to do the analog gage deal. This car is slated to be a hot rod , handeling and performance. Coilovers are another strong consideration too.
And the 6 speed...and the black GS wheels and ..........
 

MoeJr

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Jun 7, 2002
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797
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Londonderry NH USA
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Vetteless
Bein in the auto repair field I have seen alot of the mAF's on 5.0&5.7L TPI Motors go bad. Funny thing is usually when they go bad you can unplug them and the car will actually idle better and make the car mobile enuff to get it fixed. Remember this scenario well with an 87 Iroc.
 

maxrevs85

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Dec 17, 2001
Messages
709
Location
Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
Hello Moe Jr, I have had my MAF unplugged while doing alittle test and it will idle good . Just dont try to excellerate:L.....I guess thats like the limp mode. It's been a struggle ,but as I said before . Not ready to throw in the towel yet.
 

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