Vaughjw

We need help I traded my 1994 for a 1989 Iroc-Z the PO told me it had been sitting for a long time but it ran, it seemed a bit sluggish but ran smooth until I took my wife for a ride in it one evening. The car seemed to start off strong but then it felt like it fell on its face as the rpm increased.

According to PO engine is a 400 sbc low miles since rebuilt transmission is rebuilt.


We were driving down a country road and I was holding it in second at about 40mph when I felt it get sick then I heard a hissing noise lost all power and fire came out from under the hood and came over in my open t-tops, I stopped in the middle of the road(brush fires)shut the ignition off and jumped out and started trying to get the fire out my heater hosed ruptured and I was able to beat the fire out with my shirt.

We towed her home and she sat for about a year....I can't stand to see the car just sit in the shop so I have started trying to figure out what to do with her. Engine still turns over but does not crank. Im still not sure what caused it to burn but the fire was localized next to the fire wall in between the head and HVAC box, when I was beating the fire out it appeared as if the coil was on fire and dripping fire down the back of the motor.

The HVAC box is fried. (you can see the condenser) Blower motor still works windshield wipers still work. Lights still work.

My Plans:

I thought about pulling the injection off of the car and going with the basics......Carb, intake manifold, HEI, TCC lock up control and fuel pressure regulator. (am i forgeting anything?)

Or fix the old system new harness (who makes one?) new coil, gaskets and ect. Will A Firebird/TA 350 TPI harness work?

Or use a stand alone system for the TPI with TCC control.(which one is the best, and should I swap to SD when I do this)

Any advice is appreciated I need to get it going again and I do have a budget. I don't know what computer I have or even where it is for that matter (im a corvette guy)

I love this body style, this was the car I dreamed about owning when I was a little boy.

Thanks,

John Vaught

84redta

iTrader: (34)

I had a similar fire in the same location on mine. I caught mine, so nothing but vacuum lines were affected, but mine was from a back fire out of the passenger exhaust manifold that was loose at the coupler. Just a thought.

305/350 tpi harness should work, may be different pins at the ECU, but that's an easy fix, not sure though. Noone makes a new harness, you will have to find a used one for your year/app, but some years do cross, but I think '89 was a stand alone because of no 9th injector.

The rest of the options are you up to you if you want carb, or a stand alone harness, they each have their pros and cons to each.

Vaughjw

I will check that coupler, but my fire was fueled by something i'm not certain what it was but it melted the coil and HVAC box.

So a 1989 formula firebird TPI 350 harness might work?

84redta

iTrader: (34)

can't see why it wouldn't.

Vaughjw

Cool I saw one for sale I will look into it.

hellz_wings

iTrader: (2)

The ECM is under the passenger side glove box compartment. It's not really a glove box, but rather under the dash you have a plastic cover that you can take off by unscrewing like 2 or 3 screws, and then you can see it, and unscrew another 2-3 screws (can't remember exactly how many) and you will be able to pull it out.. I pull it out when tuning the car.

Vaughjw

Coool Beans,

I will get the numbers off of it tomorrow. I don't know what all has been done to this car so I better check it.

camaroinoh

Check the fuel lines a pinhole would spray that way and not noticable sense car was off just a thought. I would carb it but thats me

SBCA96

That really sucks. Good to hear you are trying to resurrect it.

Tom

Vaughjw

Hey,

I looked at the computer and it says:

GM Yada Yada
16198259
made in usa
blue harness plug

Chip says:

ADS Super Chip
1987 ADS
important:
arrows must point towards
wiring harness

I am tempted to carb it but I feel like I need to beat it first and get everything working. The PO removed a bunch of EGR crap but the air pump is still there but its not hooked to anything.

My dad always had a high rise manifold, four barrel, good heads, cam and headers and none of his engines were slow. That system is simple enough that when there is a problem its easy to diagnose.

I will look for pin holes if i ever get this thing to turn the fuel pump on again.

SBCA96

I have heard the GM Yada Yada computers give an extra 20 hp.

Seriously though... A properly working EFI engine will run better/faster/mpg/etc than
a carbed motor any day of the week. The hard part with these Bosch systems is to
get them to actually work properly.

At least by 89 they had dumped the MAF in favor of Speed Density. That is half of
the battle right there. You sneeze on a Bosch MAF and you need a new one.

Tom

Vaughjw

No I have MAF it's an 89 and that was a worry I had about buying new stuff to get it going again:

I could get an SD computer and harness and convert it right now or I can just get a replacement harness and use my 1989 computer and run MAF again.

Thats the reason I am on here hoping somebody can talk to me about it and recommend a course of action. I have a turbo in the garage and I wondered if there was any advantage to SD Speed Density as far as boost is concerned. But at this time I'm just trying to get the damage fixed from the fire but I don't want to fix the MAF system and then have to change to SD later, I would rather do it now and not waist money if I need to switch.

Vaughjw

No one has an opinion? Suggestions?

I found a place that sells a Speed Density computer and harness for around 400.00.

Or I could buy a used harness and stay with my MAF. (keep in mind I had a fire my MAF might be toast.

Thanks,

Vaughjw

So far I just have one vote on here and that was for a carb.

I will try to pull some stuff apart this weekend to see if I can see the extent of the damage.

Thanks,

Vaughjw

Ok I took the outer shielding (convoluted tubing) off of my harness and it's not nearly as bad as I thought:

The coil drop from the harness is burnt up, as is the harness that goes to the distributor from the coil.

There is also a big flat plug thats right behind the coil it has three wires going into it and two coming out and they go back to the firewall by the heater hoses and eventually go inside the cabin. I'm having trouble figuring out which leg of the harness this is and what the function of those wires is.

If some one knows what those are please let me know.

Vaughjw

Also I have a picture of the damage but I dont know how to post it.


Thanks,

ASE doc

Put the picture on your computer whether you have to scan it or if it's digital. Then select "go advanced" after you select reply. Lower down the page you will find the "Manage Attachments" button. Selecting this will allow you to browse your computer to find and post the picture

Vaughjw

There are a few wires that come out of the main harness and drop down below the heater core connections and go inside the car.

Three wire go in a flat plug and two come out.

Vaughjw

Sorry the pics are blurry i will try to get better pictures tomorrow.

AaronIROCZ

iTrader: (5)

The harness are different from a pontiac and a chevrolet. They have different connectors and pin outs under the dash. I did this on my 87 TA, I had a harness out of a 87 IROCZ and the ta had a extra connector under the dash where the camaro harness didn't. I had to swap alot of wires around but I did get it all to work. Just so you know.

Vaughjw

Oh man I'm glad to said that I was looking at a 1989 pontiac harness on flea-bay. I'm glad I didn't buy it.

All my damage is localized to the passenger side firewall behind the head.

Vaughjw

Pics with the flash on

Vaughjw

I hope these pictures help ya'll understand what I'm looking at.


Thanks,

John Vaught


ps i'm going to take a picture with my DSLR but it will be way to big to post online, but I could email it if anybody wants a better look.

ASE doc

I recognize that three pin connector. I will look at my diagrams in the AM and post what it goes to. That appears to be the source of your short circuit.

Vaughjw

Thanks,

I'm sort of stuck I ordered a shop manual but I don't have it yet.

The big flat plug has three wires coming from the main harness that go into it and two wires come out the other side and join in the harness that loops over the heater box and eventually enters the cabin through a hole under the heater core hose connections on the fire wall.

I think the wires have something to do with ignition power, fan power or possibly both. The reason I say this is that when I was cleaning the harnesses I had just pushed the car under the car port and the ignition was on so when I washed this area and the passenger side fan came on.

Also it appears as if Freon leaked out onto the exhaust manifold and fueled the fire. I have never seen that happen before. The majority of the damage is localized to the heater box. So either fuel, oil or coil dielectric sprayed on it and then caught fire.

ASE doc

I think you may be right about the wires being power to the fan. Im looking at my diagrams right now to verify.

ASE doc

The connector Im coming up with is C105. The book shows it as a two pin connector in one place than as a four pin in another place. It may only have three circuits used though. Your photo definitely looks like this connector. All that I can find going to this connector are grounds for the blower motor. I'll keep looking.

EDIT: Looked back over your photos. That has got to be the connector. I am wondering how a connector that only carries ground circuits got smoked. Unless your blower motor overloaded, but then it should have blown the fuse. Trace the wires from that connector and be sure of where they go.

Vaughjw

I think it is C105 but its not the cause of the fire just the worst victim of it. It was not shielded by convoluted tubing like the other harnesses were.

Vaughjw

[pc]

ASE doc

Yes, that was my thinkiing after I last posted. So, the question remains, what started the fire. I think someone mentioned pressurizing the fuel system to look for leaks. Exhaust manifold temps can get fairly high and any fuel or even oil can flame up. At least your wiring repairs shouldn't be too bad.

Vaughjw

LOL,

Yeah I pretty good at fixing wiring after all these years, the technical term for what I do is an Avionics Technician. I am still not sure what started the fire but we will look for leaks if we can ever get it running again. The only thing back there is the fuel pressure regulator and two injectors.

I'm going to need to totally refit all the vacuum lines most of them melted.

Is it possible for fuel to flow out the vacuum line that goes to the fuel pressure regulator?

ASE doc

Oh yes. Rupture of the regulator diaphram is a common failure. I've never seen it cause a fire, but it is definitely possible. Anything that runs off the back of the intake manifold tends to end up on the exhaust.

Vaughjw

Ok I will check it out if I ever get this thing running again.

DrewsCam

iTrader: (2)

Personally having had a camaro go up in flames let me start by saying i feel for ya... That being said i wouldn't worry right now about getting her running again what I would worry about is what fire does to metal... You can spend all this time getting it to run only to have that burnt metal rust away. If it were my car i wouldn't mess around with what you got going now until i had too. This is what I would do ...

1- pull the motor with the tranny
2- clean up the engine bay where the fire was with soda blast
3- paint entire engine bay
4- Replace all components damaged by the fire on the firewall and surrounding area ie- cowl screen, ground wire, Evaporator, ac lines, condenser, etc...
5- remove intake, valve covers, and transmission to clean them up and check for head damage or valve damage
6- Reinstall motor and tranny after ensuring they are both good and working order. (This point you should know the fire happened)
7- Repair wiring and drive her...

88gunmetalgta

iTrader: (1)

I've had transmission fluid burp up through the dipstick tube and catch fire in that area. It was on a car that had overheating problems, so when i shut it down when it was running hot, it would get a bunch of transmission fluid dumped on my headers. Burned with a thick white smoke.

Vaughjw

That could have been the cause as well.

Vaughjw

My parts came in but the weather has been bad so I haven't been working on the car I will get on it soon.

85whtz28

Where is this car at now? Is it running again? I had this recently happen to me. Mostly back together, waiting on new ecm to come in. Went ahead and did the 1227165 swap.

Vaughjw

Well it is still in the shop, I was going to fix it but I decided to do an LSX swap so I'm still collecting parts for it.

Its on the back burner my work has slowed down considerably.