1. Home
  2. Chevy Camaro and Pontiac Firebird
  3. 87 firebird questions...help

87 firebird questions...help

I have a 1987 firebird (which I factory bought back in 87), and it has just a little better than 90,000 Km.'s The problem I have is

# 1, it is somewhat not starting like it did when I bought it. Seems to start like a car with a carburator, it turns, and turns and turns and then finally, slowly starts. When I first got the car, it cranked maybe 2-3 times, then brrrrummm...it started nicely.

# 2, when the car is Warmed up, it runs great, in city or Hwy, but occasionally it will stall at stopsigns / stoplights. When this first happened I plugged a code reader in, and got a MAF sensor error. Being that the car is stored in winter (in my garage), I remove the battery every season, and, of course, the code is no longer there.

I tried cleaning the MAF sensor with brake cleaner, and blew it dry with my compressor (as recommended by a mechanic), but the car still stalls on occasion. Today, I was waiting for a train, and it was idling nicely, but when I pushed the gas to go once the train left. The car stalled on me.

ARE THESE two problems related to one another? What is this groups opinion of what may be wrong? It's been a LOOONG time that this problem has been there, I know that this particular car has a history of MAF sensor problems, and I don't want to replace a $ 150.00 MAF sensor, if it won't do any good. Will a new sensor have the "old" flaws repaired, or am I still getting the same piece of junk? PLEASE any advice will help. Don't hesitate to comment.

Reply to
Bert
Loading thread data ...

Doesn't anyone here know the answer to my question??!!

...Bert

Bert wrote:

Reply to
Bert

You didn't say what size engine it has, but it is almost 20 years old. It could just need a good tune up. If you haven't done it recently, you probably need to do a good (major) tune-up. New plugs (or clean the old ones very well and gap them) and wires, clean/replace the injectors, set the timing, check all your vacuum lines and replace as needed. Use some throttle body cleaner on it, replace your belts and hoses, etc. And maybe replace that pesky MAF sensor too.

Tom S

Reply to
Tom S

Sorry about that...it's a 2.8 V6 MPFI. I did a full tune up last year. From what I understand, they were known to have design flaws in their MAF sensors. Can you confirm this? If I change the MAF, will the after-market parts have these known flaws corrected, or am I just buying the same faulty junk that GM makes?

Reply to
Bert

Just went through much replace/repair on my 1985 Firebird 2.8 to get it through Texas emissions. 235Kmi and 4 years in storage. It took 4 tests ending with the shop chemically cleaning the intake and retarding the timing to pass; but it made it. Before I highlight the issues, the MAF was replaced back in '87 or '88, no problems since then. Two quick checks are:

1) With the car at operating temp (closed loop) tap on the MAF and listen for changes in idle, or: 2) Unplug the MAF and see if the symptoms go away. The engine should run in open loop mode which will be a little rich and sluggish. When my MAF went out, it would basically shut the engine down at speeds over 35 mph with no effect on idle or low RPM.

Back to the inspection saga ..... Car was running great at highway speeds, but idling rough, especially when warm and would stall at stoplights if over 30 seconds or so. Thinking this would not be a problem on the ASM2 (15 and 25 MPH on dyno) I run it through the test: #1 Failed NOx miserably all others good. Replaced EGR (new) and EGR solenoid (junk yard). Run a can of GM Top Engine Cleaner trough the intake; put highest octane gas I can find (93) with a healthy amount of alcohol in the tank and bring the car back as cool as practical. #2 NOx down to the floor (like 200 ppm) but HC is now about twice the standard (about 300 ppm). Thinking since NOx is no longer a problem, I just run out all the old fuel put in the lowest octane fuel I can find (87) and bring the car in as hot as practical. #3 HC drops about 20 ppm, but no significant change from #2 in anything. Now becomming annoyed I change the IAC (idle air control motor), the coolant temp sensor (could cause rich condition if computer thinks engine is cool), change the fuel filter (somewhat clogged, probably from all the alcohol and gas additives really cleaning out the tank); and put in some fresh oil. Idle is improved but will still a bit rough and ocassionally stalling at long lights. Take it in ..... #4 Virtually no change from #2 and #3. As it's the last day of my temporary registration, I succumb to leaving the car and letting them "adjust". Car passed, idles smoothly; but is really sluggish on acceleration. I didn't think changing base timing should have any effect on closed loop operation. I'm going to give it a few days relearn, but if it stays this sluggish, I'll probably try kicking the timing back up.

Good Hunting

Bert wrote:

Reply to
aeacus

I have the EXACT same problem with my Camaro.. same engine.. near same year... Spent 1200 on a full tuneup.. they replaced damn near everything except for the vaccume lines.. Which is what I am thinking is the problem... but same thing... slugggish and stalls if in gear and sitting for longer than like 30 seconds with a very rough idle.

Reply to
KITTvsKARR

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.