I've been having engine stumbling issues and have tried a few simple steps to remedy with no luck so far. Usually at or near freeway speeds. Very recently I had the same problem that forced me to the side of the road. I popped the lid to have a look. I didn't notice anything unusual aside from the usual high heat rising from the engine bay. I had it open for only a couple of minutes but when I got back on the road the problem was gone. Has me wondering if my problem is being created by high temps in the engine bay (It gets pretty hot here in Sacramento too) and if it cooled that quickly. The PO moved the coil to the trunk side of the compartment due to concerns about heat.
So, to the point, I've read lots of pros and cons of using wrap to reduce the heat. Lots of contrary opinions but the consensus seem to be that the pipes won't be damaged if they are stainless steel. Now, I'm not wanting to start a whole new controversy on this. I just want to know if it is possible to tell if they are stainless from the pic. I understand the stock Fiero set up is stainless but since the car had a swap in the past (Camaro 3.4L) I'm not sure if the stainless is still installed. This was a recent pic of the o2 sensor location that I had handy but I am happy to post additional pics if needed.
------------------ My rides... 1988 GT with a 3.4L V6 automatic 2006 Harley Sportster 'cause I love the twisties on two wheels or four.
You cannot tell from a picture. An easy test is the magnet test. Take a pick-up magnet and get a baseline value for the pull of the magnet on some known steel (the chassis of the car). Then stick the magnet on the exhaust and see if it sticks. If it does not stick at all, it is 300 series stainless (the best for exhaust). If it is weakly magnetic - the magnet sticks, but does not stick as strongly as it does to the frame then it is likely 409 stainless. If the magnet seems to stick to the exhaust just as well as it does to the frame then it is a safe bet that the exhaust is some form of mild steel.
Don't know. I just assumed that was the normal look. I'm not too familiar with the under the hood stuff yet. The Y pipe is black, but I'm pretty sure the headers are some version of stainless. Taking lateFormula's advice I tried the magnet test. The Y pipe is probably just steel. The manifold is definitely not 300 stainless since the magnet sticks but it's hard to tell the difference. Looks like shiny stainless in some areas so maybe it's 409 stainless. As usual I find myself in the gray area. Wrap or not to wrap? I had planned to wrap just the Y pipe. I probably won't wrap the headers since I can only easily get to one side and I don't know what might happen if the other side runs hotter.
A magnet will not tell you, not all stainless is non-magnetic, the type used in rifle barrels is magnetic along with lots that is used in tubing and tools. Also, even stainless can rust some, so that will not tell you either. Larry
A magnet will not tell you, not all stainless is non-magnetic, the type used in rifle barrels is magnetic along with lots that is used in tubing and tools. Also, even stainless can rust some, so that will not tell you either. Larry
Uhh yes it will. There is a large number of stainless steel alloys, but there is really only three stainless alloys used for thin wall tubing that is used for exhaust systems for automotive use: 409, 304 and 321. A magnet will not stick to 304 or 321, but will stick mildly to 409. It is not difficult to determine if your tubing is some form of mild steel vs 409 stainless with a magnet. A magnet will not adhere to 409 with anywhere near the grip it will take to any mild steel or carbon steel.
Yes, the magnetism of a stainless steel depends upon the mix of alloying metals. Also the resistance to oxidation or corrosion is a result of the alloy composition which is why some stainless steel will never show oxidation/rust, while other grades will get light surface rust over time.
[This message has been edited by lateFormula (edited 06-27-2014).]
IMO it wouldnt be worth it to wrap it. Are you haveing heat problems running hot or melting stuff?
I am having recurring issues with stumbling which only seems to happen after running for about ten minutes at high speed or under load. Seems fine around town or short trips. When it starts I can continue driving but at very reduced speed. The problem persists until I shut it off for a while. I have run through some injector cleaner, run some Seafoam, replaced the O2 sensor and the gas cap. Just trying the quick and easy solutions hoping to get lucky but not so far.
Beginning to think it's a heat related issue due to the circumstances described. Thought I might give the heat wrap a try...
1st thing that comes to mind is fuel filter. Id try replacing that.
That's on my list. Just haven't done it yet since I have to jack it up to get under there. I did just purchase some jack stands and a nice low profile floor jack with a 20" lift capability at Harbor Freight so I guess I don't have any more excuses.
Oh wait, yes I do. It's supposed to be 109 degrees here today.
That's on my list. Just haven't done it yet since I have to jack it up to get under there. I did just purchase some jack stands and a nice low profile floor jack with a 20" lift capability at Harbor Freight so I guess I don't have any more excuses.
Oh wait, yes I do. It's supposed to be 109 degrees here today.
Could do it at night but need a good light.
If theres any rust, spray it down with a rust penetrant like PB blaster and let it soak til you can get to it.
If theres any rust, spray it down with a rust penetrant like PB blaster and let it soak til you can get to it.
My fuel filter was so badly seized to the lines that I actually had to replace both lines. I did everything except use a propane torch on the fittings....not a good idea on fuel lines, lol.
Originally posted by Rsvl-Rider: I am having recurring issues with stumbling which only seems to happen after running for about ten minutes at high speed or under load. Seems fine around town or short trips. When it starts I can continue driving but at very reduced speed. The problem persists until I shut it off for a while. I have run through some injector cleaner, run some Seafoam, replaced the O2 sensor and the gas cap. Just trying the quick and easy solutions hoping to get lucky but not so far.
Beginning to think it's a heat related issue due to the circumstances described. Thought I might give the heat wrap a try...
They may be due to something else, but the symptoms you've described also sound much like the symptoms of a failing catalytic converter:
"...stumbling which only seems to happen after running for about ten minutes at high speed or under load."
"The problem persists until I shut it off for a while."
"When it starts I can continue driving but at very reduced speed."
IF you have a failing catalytic converter, the symptoms of that will become progressively worse, with, for example, the car's top speed capability deteriorating further and further over time --- eventually becoming so pathetically low that it can represent a serious threat to your safety on a freeway. And finally, the car's engine may end up just stalling and dying --- never to restart again --- until after the failing catalytic converter is replaced with a new catalytic converter.
Thanks guys. I hadn't considered that possibility. I might try the fuel filter and the ICM first just to eliminate the cheaper alternatives. I won't get a chance to get to it for a couple of weeks
I am happy to finally report that the problem was finally resolved after replacement of the ICM. Thanks to Old Lar and others! I replaced it with one from the Fiero Store on Sunday night. Wasn't able to give it a work out until today since the problem would only present after about 15 minutes of driving and my 3 mile commute is too short for that.
So today I finally got a chance to give her a run. I put over 60 hard miles on her. Warm day, rapid acceleration, and accelerating up hill. Generally having a good time. Anyway, I pushed it way past the point where It had failed several times before and she ran great!
I still think this may be a result of the component degradation caused by excessive heat in the engine bay, which was the original topic of this post. The heat whenever I open the lid always seems to surprise me even though the temp gauge seems to indicate a normal condition. Even the stuff in the trunk gets hot. The metal flashlight I carry in there was hot to the touch after my long run today. Maybe that's the nature of these cars but it still doesn't seem right to me...
Anyway I want to say thanks to all you guys that responded with suggestions. With one simple question here I always learn so much. Thanks!
Just something to think about. If your catalytic converter is old it probably isn't breathing right which can lead to high heat in the engine bay. The old cc's are notorious for plugging up and choking an engine. One reason some like to cut them out completely. How ever a good high flow cat will do the job and probably reduce your heat issues to boot. You will find more hp too. DD
Originally posted by Rsvl-Rider: I am happy to finally report that the problem was finally resolved after replacement of the ICM....
One thing I noticed is that you have no insulation on your crossover. The 88s normally come with a heavy insulated foil wrap, around the crossover. (The earlier V6s have tin shields.) When I removed that wrap from my Formula, I noticed that the underhood temps seemed to be very high. (Wasn't really paying attention to the temps while I still had the insulation in place.) Coincidentally, it was shortly after that that I started having ICM issues.
I believe that the Fiero Store sells a thermal coated (and ported) crossover. If that's not an option, there are these guys. Cost me like $200 to coat a set of Sprints and a crossover. And a brochure.
If it were me, I would probably wrap the crossover, and save my coins for a replacement, in case the original rusts through. I seem to remember that it's stainless, however. I don't think it will.
------------------ Raydar 88 Formula IMSA Fastback. 4.9, NVG T550 Praise the Lowered!
[This message has been edited by Raydar (edited 07-23-2014).]
One thing I noticed is that you have no insulation on your crossover. The 88s normally come with a heavy insulated foil wrap, around the crossover. (The earlier V6s have tin shields.) When I removed that wrap from my Formula, I noticed that the underhood temps seemed to be very high. (Wasn't really paying attention to the temps while I still had the insulation in place.) Coincidentally, it was shortly after that that I started having ICM issues.
I'm in California so I don't think there is much I can do about changing the cat. Would a "high flow cat" suggested by Diamond Dave be legal in California? Probably one of those 49 state things. I did do a tap test as has been suggested here and I didn't hear anything amiss. It actually looks pretty good and I am guessing it was replaced when the PO upgraded the exhaust system.
I wasn't aware that the crossover on the 88's were originally wrapped. Can someone please post a pic of what that looks like?
Looks like sort of a corrugated heat sleeve from before the EGR and under the air intake but I can't tell how far down it goes in that pic. Does it continue on down to the y-pipe, O2 sensor or beyond?
Here is a pic of mine. Looks like a flat horizontal piece of tin shielding placed just above the exhaust and below the distributor, EGR tube and throttle body, although it does seem to have some sort of woven heat fabric underneath. (the coil is in the trunk) The pipe itself is bare all the way down past the y-pipe.
It is an 88 even with the chrome plenum. It had a 3.4L installed by the PO. Seems like he made some changes to the heat shielding too.
[This message has been edited by Rsvl-Rider (edited 07-27-2014).]
Looks like sort of a corrugated heat sleeve from before the EGR and under the air intake but I can't tell how far down it goes in that pic. Does it continue on down to the y-pipe, O2 sensor or beyond?
This is a picture of a club member's cracked Y-pipe, but it shows the size of the sleeve nevertheless.
