Sunbird Help Please

Hello All,

I have a 89 sunbird that has the strangest problem... Alittle history first.

Head gasket was just replaced... It ran for a while.. then just stopped one day. It'll crank over, but will blow gas out of the TB unit. I checked the timing to see if the belt jumped... and it's fine. So then I'm thinking its a sensor. Since I can get it to run at WOT... (barley). I replace the TPS.. that wasn't it.

It looks like its getting way too much gas... as it starts to puddle in the bottom of the intake. Just from cranking it over a bit. Replaced the injector, and it made no difference. tried a different ECM.. new and a used one from a running car.. again, no difference.

I even tried a different MAP, IAC, and IAT sensors.. again.. no differece.

Now for the Strange part... It will now run... badly.. but only with all of the sensors unplugged... MAP, IAC, IAT, TPS... it'll run, spitting gas a bit, but not bad. If I try to plug in the TPS, or IAC it'll chug then die.

I'm lost here. Is there anything that I could be missing. the compression is great.. 175-180 on all 4.

I'm almost wondering if it could be Ignition related... but am leary of just throwing any more money at it.

any suggestions

TIA

Jeff

Hi jeff I also have an 89 sunbird and have the exact same problem... hope we find out soon what it is ... and hopefully not the computer!

It's not the comuter for me at least.. I bought a new one.. salvaged another one out of a runner at the junk yard.. and neither made a difference :banghead: :banghead:

Man.. I thought I was a good Mechanic :loser: :loser: This one has me stumped.

My Husband too .... Thanks to you we won't replace all those parts you have listed you have saved us alot of money. We did replace the tps tho. My Brother had pulled on of the vacuum lines of and places his thumb over it and it ran for 15 minutes and damned if it will start again! GOOD LUCK

Hi Jeff it's me again. The difference between our cars is yours is fuel injected and mine carberator. I have been reading and came across this. Did you happen to check your cold start fuel injector valve?

Hi Jeff it's me again. The difference between our cars is yours is fuel injected and mine carberator. I have been reading and came across this. Did you happen to check your cold start fuel injector valve?

Cold start FI valve.... I havent heard of this before. Any further detail. the only valve on my Throttle body (except the butterfly in the ventrui) is the IAC... and that is working. I'm actually starting to think its electrical... as we have both done major engine work... And I have heard of ECM's with grounding problems causing Wacky symptoms. I plan on going over all the wireing to see if the all of the grounds are intact... then on to the power circuits. Don't have time for that till tomorrow though.

If I'm missing that valve youre talking about... let me know where to look.
Thanks

I found it at autozone.com under repair info ... parts and how to ... then under F for fuel. here is the site hope it works
http://www1.autozone.com/servlet/UiBroker?ForwardPage=az/cds/en_us/0900823d/80/04/b7/61/0900823d8004b761.jsp

it keeps adding that [url] before and after the site address so when you copy and paste don't copy that lol

Never mind I guess you can just click on it lol

AAAhhhhh... That looks like its for a MPFI system... TBI systems don't have that. All of my fuel lines just go to the regular injector. WHich sits above the Butterfly.

GOt a lead on something... Gonna try it tonight and see if it works :swear: :screwy:

How did you get a carburated model??? I thought the last year for those was 83. Do you have the OHC Brazilian engine?? (silver valve cover with OHC on it & dist comming off the driver side of it)

Thanks.

Did it work?

Did it work?


Wellll.... I had it running nice and smooth.. no backfireing... Had to retard the timing as far as it would go... but it worked..... :smokin: Then I just had to try pluging in the sensors... Well, as soon as the TPS hit it sarted its thing again... sputtering soo bad that before I could shut it off, it threw the timing belt :banghead: :banghead:

Its ok.. though, I think the previous owner was BSing me with his "It ran for two months" line. I think he just replaced it, couldn't get it started.. then decided to pass the buck.

Interesting note... While I was taking it apart to fix the belt (not done yet btw)... It was missing a intake manifold nut, the water pump bolts were loose(barely in at all), and the rear engine mount was real loose... :nono:

So, I've just decided to start right from square 1... Get the timing belt on, fix the intake nut (probably causing a Vac. leak), get everything tight, and cross my fingers.

ALthough, I'm not doing anything till after I get back from Vac. Aug. 9 :biggrin: :biggrin:

I sure hope you fare better than I have.

Hey have a great time on vaction!!! Can I ask what you had to do to stop the gas from spewing out? lol By the way mine is exactly like yours ... Hubby thought it had a carberator .. but my brother said it is a fuel injected carberator! lol So we are just about to tow it to a real mechanic!

I'm not exactly sure what I did to make it run good.. Aside from unplugging all the sensors... I still shot pulsed of air/fuel out the TB untill I backed off the timing.. then it ran soooooo nice... no popping and idled great. Plugged in the IAC.. the idle dropped but still smooth... Then the TPS.. and all he!! broke loose. I'll find out more after I get the Timing belt back on. While I was having the problem it seemed to run better with a Vac. leak.. I actually removed the IAC and it would run like that.. better than with it in the hole...lol.

I'm thinking that if I still have this problem after I get the Timing belt on, I'm going to make a regular carb fit on there.....lol. An old 1bbl off a dodge truck with a wooden adapter/spacer plate should work just fine :p (did I mention that I hate ECM controlled cars :rolleyes: )

I can't wait till Vac... The days don't go by fast enough :)

Did you run a diagnostic test? I was reading in the repair manual that there is an inline ECM fuse. If the car runs without the sensors wouldn't it be something like that? I don't have the repair manual here to tell you where it is .. but it was between the computer and something lol My Husband would highly agree with you on the Carb! lol

Did you run a diagnostic test? I was reading in the repair manual that there is an inline ECM fuse. If the car runs without the sensors wouldn't it be something like that? I don't have the repair manual here to tell you where it is .. but it was between the computer and something lol My Husband would highly agree with you on the Carb! lol

I have one of those "Haynes" manuels for it... The thing is, the injector fires.. the ECM has to have power to control that, plus the sensors are working (just not right) as it makes a difference in how the car runs when I do plug them in... This is baffeling. I really think that the former owner, jumped the belt a tooth (I don't think he had the tensioner adjusted right). I'm going to try the belt tomorrow.... IF I can get that dang Water Pump to move. :disappoin

Could never get it to run long enough to do a Diag. Test.... Without the sensors yes... but a Diag. test without sensors is pointless...lol.

If you take yours to a Mech. let me know what they find....

Hiya Jeff , Have you learned any more about the problem? Had ours towed to the mechanic on Monday, haven't heard anything yet!
Jane

No.... Gonna send it to the yard.

Refinanced house... bought new car. Don't need a beater for me anymore (Got wifes old car...hehe)

Gonna go to the Junk Yard soon.. anything you want off of it??? Yours for shipping

Since you have good compression, you can rule out a bent valve. I would look at the distributor, where it engages the end of the cam. When the bushings get loose in the distributor, it can cause it to become misaligned with the pick up in the distributor and make it die. When you disconnect the sensors, the ecm defaults to limp home mode and doesn't attempt to advance the timing, so it will run, although poorly. When the other sensors are hooked up, the ECM detects you giving it gas, attempts to advance the timing, and the pickup coil moves, causing the car to die..