Okay Ladies and Gents i have a problem i just moved to AZ and i have been slowly restoring my 88 iroc z do to the high temp out here i had to replace the water pump in the car and everything was fine but the other day i drove it 40 min out of town at about 105 out side and the car was starting to overheat. the temp gauge maxed out and the engine started to choke it self and back fire. both fans work and with the ac on they work at the same time now i waited tell the sun went down and came back for the car. it was 80 to 90 at 1100pm and i drove the car back home the temp gauge didnt reach 200 by the time i got home. i did notice that four things happend 1. the car is quite now it dosent seem to have the loud purr we are all know comes from a stock exhaust. 2 I lost horsepower she dosent launch off the line or even when you gun it at all. 3 when you stand next to the driver side to back of the car there is a high amount of exhaust fumes. 4 on my way home on the high way the check engine light came on and its a code 34 which i know is a MAF sensor as the engine is a 305 TPI and have been working the issue. if anybody can help that would be great

 

This is more in regard to the overheating, but what temp thermostat do you have? I just put a 164degree thermostat in mine, but it may be even more helpful in your situation due to driving in high heat.

As far as exhaust, i couldn't tell ya. I'm a novice myself, so in my case if it were suspect for me, i'd work from the front to back. obviously it sounds like there's no holes, since it's quieter than normal, but that would be my best suggestion. I suppose, due to climate i'd check your air fuel mixture too. climate could grately affect a cars perfomance and fuel/air mixture. it may explain some of the bogging and even the high exhaust fumes. though, you'd need to verify for dry heat what the air/fuel ratio should be. especially if you come from a northern state that has more drastic weather changes like the one i'm in, MN. i had a car i drove from here to colorado and was noticing bogging for a month or so after i returned and had it tuned up and they reset all the fuel mixture settings for me and it stopped. Just something to think about anyways.

 

Where in AZ are you? I'm in tucson, and since I've restored mine, it is under cover in the garage. These temps are hell on cars. Especially higer performance ones with aluminum heads. If you are still stock, check the following.

1. Make sure the water pump you installed is the correct one, there are two options depending on Vbelt vs. Serpentine. I believe an 88 was a serp. belt.
2. Make sure the air dam under the car is installed.
3. Make sure your radiatior and condensor are free and clear of obstruction. Flushing should be mandatory!
4. make sure you have a clean 50/50 coolant to DISTILLED water, especialy in AZ, where tap water is loaded with calcium, magnesium, and sodium that can and will precipitate out.
5. Air fuel ratio is probobly not a problem due to internal adjustment, but pull a plug anyway and see if you are too lean. I would say with our oxygenated fuels here and thinner air you will be rich rather than lean.
6. Install a stock type thermostat 180* I believe is close.

Now to the noises, there is a chance you could have cracked an exhaust manifold, or more likely you blew a lot of carbon out and could have clogged up your cat and the fumes you notice are coming out of a likely leak in the system. That could also help explain your power loss as well. Check for any coolant leaks to be sure you didn't crack the head or block. Check you oil as well for any water in the oil. If you want to drive that car in the heat here you will need to be certain your entire cooling system is completely dialed in, or you will get stranded.

 

Just my $.02, but I would also check for a blocked catalytic converter. If it is even partially blocked it could cause the engine to not breathe which could be contributing to your loss of power and the mass airflow code. Restricted exhaust also prevents the engine from removing heat which could explain the overheating condition.

 

See 1st sentence after step 6....

 

did you purge all the air from the coolant? it is possible some air was still trapped and caused it to run hot. best way to do it is jack the right front of the car up, start it up with the cap off, and watch for bubbling. with it running that hot, chances are it melted the cat (previously stated), which can cause a maf code (previously stated as well). the best way to check the cat is remove the o2 sensor and run it. if it has a lot of force blowing exhaust out of the o2 bung, its clogged. or you can cut the exhaust off after the cat and just hollow it out. will make it a bit louder and a bit more powerful as well

 

okay first of all thanks to everybody helping me out so far with everybody giving me tips i have done the following.
1. there are no leaks in the engine or engine bay to include water in the oil.
2.about five months ago i replaced the air damn when i found out the car first originally came with one and the guy i bought the car off shortened now since i was in upstate ny it doesnt get hot so i didnt notice it right away.
3. when i installed the new water pump i did a flush and since the radiator is less the a year old i didnt find any calcium build up or any debrie.
4. i used prediluted 50/50 antifreeze, now being out here should i mix my self or does it really mater?
5. i havent checked the air/ fuel ratio yet so when i get it back from the shop i will check that.
6. i have a stock 180 thermastat i do have a 164 spare i could put in but which is better for out here the stock or the 164.

i took it to the shop because i couldnt find any cracks or leaks in the exhaust lines they told me today that they couldnt find anything either and that my overheating problem is from my after market fans not pulling or pushing enough. i have a 13 inch fan set a primary and a 6 inch fan set to secondary the 13 inch fan is cfm rated at 1540 and im not sure about the 6 inch cuz a buddy gave it to me. and there mounted directly on the radiator. now im not 100 percent but i think the oem fans were pushes and there where rated cfm of 500 a piece anybody know if that is true and could that be a part of my problem? oh and i live in gilbert djs383

 

the fan ratings are ok. not the best for 110 with a/c on though, i would suggest dual 12" fans of at least 1000 each.

 

This sounds plausible since your issue seemed to happen suddenly. I had a car that had a plugged converter, and it cut the power waaayy down. Your exhaust becoming quieter?? Definitely sounds like a blockage in your exhaust. If not the converter, somewhere else.

 

okay after trying everybody's tips and ideas to know avail. the car runs a little better and the sound came back. when i took the car to the shop they said they couldnt find anything wrong with the exhaust but they said it may have something to do with the overheating which they followed with i should put the right fans in. which brings me to my next problem i bought darle dual 12 inch high output fans rated at 3000 cfm a fan. They work amazing but they are 40/60 amp fans and i am having a problem finding a alternator to run the fans and the a/c so if anybody can help with that or have ideas that would be great and i hope that this will solve my exhaust problem to if there are linked. i did the math and i need a alternator with a minimum of 160 amps and a single wire setup. thanks to all those that helped me diag the exhaust