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Hi, I have a 1987 Vette. It is running very rich, blows black smoke rich, and when it begins to warm up it starts to run rough and acts like its loading up. When you give it some Rpm's it gets a miss and when returned to idle it dies. Now after letting it sit and coming back to mess with it, it smells of raw gas and is hard to crank, when it eventually does it sputters badly and dies. Almost like a car that has flooded. I replaced the coil, cap and rotor with a kit from DUI. It also has a new egr valve and IAC, and temp sensors aside from the MAT, along with new injectors. The throttle body and intake have all been taken apart and cleaned and had new gaskets installed. The TPS and fuel pressure checks out good and there is no fuel in the vacuum line to the fuel regulator. It is now giving code 45, witch suggests the next thing on the list to check is the o2 sensor. The only things that aren't new is the MAF, MAT, ECM, o2 sensor and TPS, plugs are new-ish, I've cleaned them, but they probably have been through the ringer now.... Thats all I can think of off hand. Any suggestions on what could be going on? Thanks.
 

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Id adjust the TPS and IAC as a quick check, as its easily done and costs nothing, your running rich is obviously something related to a defective control sensor or defective part,
code 45 is a rich exhaust, you already know your running rich, fuel enters the cylinders from the injectors or a defective fuel pressure regulator, and the maf is the major control on fuel flow rates, test heat sensor.
Id start by verifying the injectors are not leaking, they may be new, but that does not mean they are functioning correctly,
Id test and if required replace the MAF and the relays behind the battery on the engine compartment firewall ,and the oxygen sensors as they are most likely trash at this point, you also did not mention the fuel pressure, if you turn on the key but not start the engine, the fuel pump should pressurize the fuel rail, to about 40 psi, it should remain pressurized for at least 6=7 minutes before slowly losing pressure, if it loses pressure the fuel is leaking at the injectors or fuel pressure regulator or the fuel pump, if its the fuel pump, it would not cause your issue, if you block off the fuel pressure return line and it still loses pressure you know its the injectors

http://garage.grumpysperformance.com/index.php?threads/i-want-some-suggestions-on-potential-problem-sources-1987-corvette.15596/#post-93275

 

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Discussion Starter #3
Id adjust the TPS and IAC as a quick check, as its easily done and costs nothing, your running rich is obviously something related to a defective control sensor or defective part,
code 45 is a rich exhaust, you already know your running rich, fuel enters the cylinders from the injectors or a defective fuel pressure regulator, and the maf is the major control on fuel flow rates, test heat sensor.
Id start by verifying the injectors are not leaking, they may be new, but that does not mean they are functioning correctly,
Id test and if required replace the MAF and the relays behind the battery on the engine compartment firewall ,and the oxygen sensors as they are most likely trash at this point, you also did not mention the fuel pressure, if you turn on the key but not start the engine, the fuel pump should pressurize the fuel rail, to about 40 psi, it should remain pressurized for at least 6=7 minutes before slowly losing pressure, if it loses pressure the fuel is leaking at the injectors or fuel pressure regulator or the fuel pump, if its the fuel pump, it would not cause your issue, if you block off the fuel pressure return line and it still loses pressure you know its the injectors

http://garage.grumpysperformance.com/index.php?threads/i-want-some-suggestions-on-potential-problem-sources-1987-corvette.15596/#post-93275
I rechecked the fuel pressure and it did not drop off. I rechecked the TPS also, it has previously been adjusted to the correct spec. Pulled the o2 sensor out, and as expected it was trashed, picked up a new Bosch unit. I will do the reset on the IAC next. Also got the relays out from behind the battery, are they suppose to be the same part number? I saw a thread on a Camaro forum that said they are suppose to be different. Thankyou for the links, they are alot of help.
 

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Glad I could help,
I built that whole web site to help the guys with less experience wade through the all too typical, delays, B.S. most repair shops provide,
and allow guys to learn, how to think logically, isolate and test,
and in the process learn how to do their own correct diagnoses and repair work without having to spend 50 plus years gaining personal experience the hard way.:thumbsup:

I got really tired of being lied to, stalled, and having crappy machine work passed off as "NORMAL" and having guys try to B.S. you so the billing could be pushed higher as I slowly gained experience and knowledge.
 

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Discussion Starter #5
Glad I could help,
I built that whole web site to help the guys with less experience wade through the all too typical, delays, B.S. most repair shops provide,
and allow guys to learn, how to think logically, isolate and test,
and in the process learn how to do their own correct diagnoses and repair work without having to spend 50 plus years gaining personal experience the hard way.:thumbsup:

I got really tired of being lied to, stalled, and having crappy machine work passed off as "NORMAL" and having guys try to B.S. you so the billing could be pushed higher as I slowly gained experience and knowledge.
Man, you ain't lying. Alot of shops just are not worth a damn, not to mention dealers these days. And the parts you get to... if they are not some overpriced, cheap china replacement... It's a chinese counterfeit in a brand name box. Just makes everything harder and take longer. Well, I got back to messing with the car. Went ahead and got a new Delphi MAF, MAF relay and burn off relay. Checked all the voltage to them and it checks out good. Also got new spark plugs. Cranked it up and it started doing the same thing, blowing black smoke, sounding like it's got a big cam in it and missing. So this lead me to look at the computer. I checked to see if it has ground and it does. I pulled it out and it has the service number # 1227165. I've read about these specifically being prone to failure, so it's suspected that this may be the problem. Now, do I send this thing off and have it gone through or go ahead and get a new one? Also, are there any grounds that go to the back of the cylinder heads? Thanks again for the help.
 

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The 85 had a seperate cold start inj,after that it was built into the ecm to richen the mix,there's a water temp sender in the right side head,check the connection there.Just a no cost thought.
Somewhere on grumpys site theres a procrdure the ecm goes thru on start up.
Theres ground wires bolted to the motor on the drivers side by the disy/oil presure switch.
I gota split for wowk,so im short on time.
 

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The 85 had a seperate cold start inj,after that it was built into the ecm to richen the mix,there's a water temp sender in the right side head,check the connection there.Just a no cost thought.
Somewhere on grumpys site theres a procrdure the ecm goes thru on start up.
Theres ground wires bolted to the motor on the drivers side by the disy/oil presure switch.
I gota split for wowk,so im short on time.
Think the 86 has one also.
 

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Hi, I have a 1987 Vette. It is running very rich, blows black smoke rich, and when it begins to warm up it starts to run rough and acts like its loading up. When you give it some Rpm's it gets a miss and when returned to idle it dies. Now after letting it sit and coming back to mess with it, it smells of raw gas and is hard to crank, when it eventually does it sputters badly and dies. Almost like a car that has flooded. I replaced the coil, cap and rotor with a kit from DUI. It also has a new egr valve and IAC, and temp sensors aside from the MAT, along with new injectors. The throttle body and intake have all been taken apart and cleaned and had new gaskets installed. The TPS and fuel pressure checks out good and there is no fuel in the vacuum line to the fuel regulator. It is now giving code 45, witch suggests the next thing on the list to check is the o2 sensor. The only things that aren't new is the MAF, MAT, ECM, o2 sensor and TPS, plugs are new-ish, I've cleaned them, but they probably have been through the ringer now.... Thats all I can think of off hand. Any suggestions on what could be going on? Thanks.
Well get ECM back yet? What is story ?
 

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Discussion Starter #11
Well get ECM back yet? What is story ?
No real difference, I think I may have found part of the problem or made it worse. Did a check on the voltage to all the pins to the ECM with it in and out, with and without the ignition on, and it all checked out good with a reference paper I found that i need to post. Checked the fuel pump at the ALDL and it runs, also has the proper voltage to the fuel pump relay on the orange wire and the green and white wire to the ECU, checked the injector resistance and it was good. It also hold 40 psi of fuel pressure. Ordered a new diaphragm and adjustable fuel pressure regulator but haven't installed it yet. Got a deal on a Hypertech Thermo Master EPROM and put it in and along with a new ECM. Well, now it will crank, and fire for a moment and then cut off. Hooked a noid light to the injector plugs and they are not getting a signal now... So no injector pulse. Currently still researching and checking things out.
 

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Discussion Starter #15
What eproms?
I figured that maybe the EPROM held the parameters of another car in its memory, (like key resistance for the VATS) since the Hypertech EPROM I got was used, I thought maybe that had something to do with it. But... I found the problem, after going to check the purple and white pulse wire at the base of the distributor, it turns out the clip is broke and it slid out of it. SO that was why it had no injector pulse. Need to fix that... After letting it run a bit to get it up to temp to mess with the timing and set the tps, it went back to running rich as a Rosie O'Donnell and chopping like it's got a cam in it. After that I decided to research the fuel injectors. The guy I bought the car from said they were Bosch, and they look like Bosch Green Giants (after research), witch are 42LB injectors, and that is way to much. The car is only suppose to have 22LB injectors. Stuck some clay on the back of one and got a number, they are indeed 42 LB injectors, but made as a knockoff by a China company called "Mostplus" part# M02A42. so I do believe THATS where the richness is coming from. I'm sure they probably leak aswell. On the plus side, the car doesn't die anymore.
 

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I'm fairly sure if you ask around you can find someone whos upgraded their old OEM,
injectors who will be only too glad to sell you a set of now un-used stock 22 lb injectors
 
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