Good afternoon. This past Friday my Fiero stranded me. It was running fine, then it started sputtering a bit on acceleration. I got it to my destination and turned off the car. About 2 hours passed and I went out and the car would start and idle then die as soon as the throttle was given. You could smell gas very strong. This says to me that it is flooding. In my research I have seen O2, MAP, and coolant temp sensor listed as causes. Now it will start and idle for a few seconds and die. Car is the 2.8 88 GT. Any help or suggestions would be appreciated. Tomorrow I will go out and jump the ALDL to see what trouble codes flash, if any. Also the EGR was deleted physically, just not sure if it was in the computer. It was running fine for a full week. As long as I have had this car... I will start figuring out hoe to test the MAP. I did try unplugging the O2 to see if the computer would revert to base code. That didnt have any effect. The PO says he put new injectors and fuel regulator on the car since it sat for 8 years. He did give me a box that has a brand new EGR and tube (braided from the fiero store) I am not sure if the Solenoid is still there or not, I need to figure out where it is supposed to be located. I read that the vacuum line to the MAP sensor can get clogged with carbon. I went to locate the lines and it seems they run under the intake and disappear. does it connect under the intake? Thanks in advance for any help!
------------------ "HICCUPP" 1988 2.8 GT Ocelot SS exhaust
Put a fuel pressure tester on there... to not only see what the fuel pressure is while the pump is running, but also to see how quickly it drops when power is cut from the pump.
Start the car then shut it off. Pull the vacuum line off of the fuel pressure regulator. If you smell gas in the vacuum line, it means the FPR diaphragm has a hole in it and needs to be replaced.
Check your timing if you can. If for some reason your distributor got loose and moved a lot, it can cause similar problems. I would take the cap off and make sure the rotor and everything on the inside is still in decent shape. I have seen rotors come apart but usually when that happens the engine won't fire at all.
Put a fuel pressure tester on there... to not only see what the fuel pressure is while the pump is running, but also to see how quickly it drops when power is cut from the pump.
Ok finally got around to this, I had birthdays and life...
Key at on position 24 PSI. Key in off position 22 PSI after a couple minutes. Cranking 30 PSI Car quit starting... holds 28 PSI after 10 min.
Also took off MAP and cleaned with MAP cleaner (pretty sure this is just an electronic connector cleaner that CRC has labeled MAP to charge more... no change, car did start and idle for about 30 seconds and did respond to throttle. No longer starting again. Car was cold and sitting for days before this attempt to start. now will crank and sputter with no start, still smell gas. Not sure if MAP cleaner was the ignition source on the start and run. I think maybe I am getting a cold spark, next I am checking the Ignition. Any other ideas would be welcome. The Factory service manual is not as through as I hoped it would be compared to newer cars...
Start the car then shut it off. Pull the vacuum line off of the fuel pressure regulator. If you smell gas in the vacuum line, it means the FPR diaphragm has a hole in it and needs to be replaced.
Check your timing if you can. If for some reason your distributor got loose and moved a lot, it can cause similar problems. I would take the cap off and make sure the rotor and everything on the inside is still in decent shape. I have seen rotors come apart but usually when that happens the engine won't fire at all.
I figure since I am holding fuel pressure for over 10 minutes there isnt a hole in the FPR diaphragm. I am will be checking ignition next. I feel like this maybe where the problem is. I think the start and run I had was due to the cleaner that I used in the MAP lines and I get a stutter after a long time cranking, so I am thinking maybe the engine is flooding due to miss timed / cold spark.
I figure since I am holding fuel pressure for over 10 minutes there isnt a hole in the FPR diaphragm. I am will be checking ignition next. I feel like this maybe where the problem is. I think the start and run I had was due to the cleaner that I used in the MAP lines and I get a stutter after a long time cranking, so I am thinking maybe the engine is flooding due to miss timed / cold spark.
I should have done this first... I have a code 33, 34 - MAP sensor issue.. I also have 42 EST Fault.
It did start again, ran for a few seconds and died again and will not restart.
The MAP codes may be from when I had the MAP unplugged to gain better access to the fuel pressure valve and cranking to get a pressure reading. Being unplugged should give those codes I would think. Also plugs look good except covered in gas from flooding. Wires are new, cap and rotor are new. Now the original owner has installed an MSD coil and it is wired in aftermarket not with a standard weather pack connector. Now all of these look to be wired well using spade wire connectors. I take it that the Ignition module is the black box under the cap that has 2 wire harnesses plugged into it? One of which is going to the coil the 2nd passes under the intake. How do I test the IM? From what I have read it sounds like it could be the IM not working, or the ECU or bad wiring. Could it jumping timing on the distributor cause this?
Here is the timeline:
Car running well for 1 week. Friday afternoon throttle started to bog while driving. If pedal pumped it would push through and accelerate with a lot of sputter. giving gas hard seemed to flood it. Parked car for a few hours, came out to diagnose and it would idle but as soon as you touch the throttle it would die. Get car towed home, car will not start. Leave sitting for about 2 weeks and that brings me to now with all I have already described. I dont want to start throwing parts at it blindly. That will get expensive fast. top of my mind would be MAP, Ignition Module, and TPS maybe??
do some searching on this site about MSD ignition systems; very likely part of your problem.
also note, the Fiero has a non intuitive throttle setup where you actually 'clear' the fuel by depressing the gas pedal....the opposite of carburetor cars. The computer decides how much fuel to send based on sensor information, so a bad sensor can make the car appear to be flooded.
[This message has been edited by Gall757 (edited 08-06-2019).]
Key at on position 24 PSI. Key in off position 22 PSI after a couple minutes. Cranking 30 PSI Car quit starting... holds 28 PSI after 10 min.
I figure since I am holding fuel pressure for over 10 minutes there isnt a hole in the FPR diaphragm. I am will be checking ignition next. I feel like this maybe where the problem is.
Those fuel pressure readings are way too low.
I'm not trying to give you a bad time, but when you went through the trouble of testing the fuel pressure (as advised to do), did you not also look up what the readings were supposed to be?
I agree with Patrick. The pressures are too low. Just as a possible cause, change your fuel filter and see if the pressure rises before assuming it's the fuel pump.
I'm not trying to give you a bad time, but when you went through the trouble of testing the fuel pressure (as advised to do), did you not also look up what the readings are supposed to be?
I did read on it but I must have looked at bad information as I thought the 24 PSI holding was normal and since I couldnt get it to run the 32 sounded ok... . I will change fuel filter and see what shakes loose at worst I am out 5 bucks. To clearify it should be at 45 PSI not running and drop when it is running to around the PSI I had while cranking?
I am still going to take care of those spade connections by soldering and heat shrinking then taping.
So if it is low pressure why does it smell like gas and flooding? Also when I pulled spark plugs they were soaked in gas.
do some searching on this site about MSD ignition systems; very likely part of your problem.
also note, the Fiero has a non intuitive throttle setup where you actually 'clear' the fuel by depressing the gas pedal....the opposite of carburetor cars. The computer decides how much fuel to send based on sensor information, so a bad sensor can make the car appear to be flooded.
Well it is only an MSD coil not a whole system. If none of the above fuel issues resolve this then I will look at the coil as a possible cause. It is possible since as I said above when I pulled the spark plugs they were covered in gas which could be not enough heat from the coil.
That's the problem. The coil is operating at a very high voltage compared to stock, and it tends to damage other components in the system. The MSD stuff is designed for racing and should be used as a complete system. But I agree.....fix that fuel pressure first. Engine running, it should be close to 40 psi.
[This message has been edited by Gall757 (edited 08-06-2019).]
Ok, verified I do not have spark. What is this pig tail? it does not look stock. It looks like a capacitor that has been added to the coil power supply line. It is also grounded via the black wire to the exhaust manifold. This was covered in heat shrink. The white connector looks like it may have been stock, but this pig tail is connected via spade connectors. If this is a add on then I plan to remove it as the wires were burnt. I went ahead and covered the burnt spot in a new piece of heat shrink in case this cap is needed here. I also found the connector plugged into the coil has broken insulation right at the connector, so I will be replacing the entire connector. I plan to replace the coil with an OE coil as well.
I have no idea what is going on there.....a grounded capacitor?
So I take it this is not supposed to be here? I mean it was running with it before, however if it is not supposed to be there and no one can tell me why this would be here and it is not a stock item then I will take it out of the loop.
So I take it this is not supposed to be here? I mean it was running with it before, however if it is not supposed to be there and no one can tell me why this would be here and it is not a stock item then I will take it out of the loop.
It looks like a home-made tach filter.....but let's hear from the wiring experts...(which I am not).
Well between the coil and new pig tail there is life in my "Hiccupp". It fires up at a key bump like it did before and is running like a top. I did eliminate the odd grounded capacitor set up but I did keep it in case another problem arises, but if it is a tach filter like you suggested then I will order the correct set up from the Fiero Store. I will look into the fuel pressure issue as well, but now that i can drive her I can get her to a lift which is always preferable to my gravel drive... Thank you all for your help in figuring this out! I will reset the ECU codes and see if the 33,34,42 codes come back. It does look like the MSD coil was again the issue here. This did give me the opportunity to clean up the previous owner's wiring job. Now that I have my Fiero running like a top again I get to tackle the power steering on my truck... No PS in a 2800 pound car is a lot different then driving a 6000 lb truck.
Gall757 is 100% correct, the yellow cap is somebody's idea of a tach filter. The factory filter contains two capacitors wired between ground and the signal wire from the coil to the tach (those two wires going to the factory connector you've circled). There is also a inline resistor between those two capacitors on the signal side.
Key at on position 24 PSI. Key in off position 22 PSI after a couple minutes. Cranking 30 PSI
Now that I have my Fiero running like a top again...
It's great that you got the engine running after working on the ignition... but I'd say either those fuel pressure readings are incorrect (faulty fuel pressure tester?), or if they're accurate, your engine will be running lean at higher RPMs.
It's great that you got the engine running after working on the ignition... but I'd say either those fuel pressure readings are incorrect (faulty fuel pressure tester?), or if they're accurate, your engine will be running lean at higher RPMs.
Yes I do need to look into the low fuel pressure. It was a rent-a-tool from Autozone so it may not have been accurate, but I am going to assume it was. I bought a new fuel filter so I am going to change that. The car sat for 9 years before I bought it. The previous owner did change the injectors, and regulator. However I know he didnt drain the tank since it ran like ass for the first 200ish miles i am guessing since it is in Kilos and I didnt pay attention to how many rolled.. ( it had a full tank) I also ran it dry by accident since it said I had a 1/4 tank of gas but it was empty. My guess is varnish has the float sticking once it gets to 1/4 tank. I dont know since I have not driven much since I got new gas in it. I am willing to bet the fuel filter is getting clogged from the near decade of sitting and varnish. PO said it had 3/4 a tank of old gas and a 1/4 of new with seafoam in it. I should have siphoned it out, but it was running so I decided to burn it out.... I have had this car since 7/14. I know I am going to have to chase out the bugs from it sitting so I will be learning a lot about these cars in the process. I hope I can continue to lean on the community here for help
That bit of information would have been very helpful to us. We have seen what sitting does to these cars, and with that added seafoam info there is not much doubt that the fuel filter is toast. Your fuel tank sender error is very common and probably will not improve until it is replaced.
Gall757 is 100% correct, the yellow cap is somebody's idea of a tach filter. The factory filter contains two capacitors wired between ground and the signal wire from the coil to the tach (those two wires going to the factory connector you've circled). There is also a inline resistor between those two capacitors on the signal side.
Thank you for the verification. I will have to order the correct filter and wire it back in since I deleted the whole bit when I ran the new pigtail since none of it looked right. So far I have not seen any adverse effects from it being gone. my tach isn't bouncing around or anything. I still need to figure out the fan switch, I have to run the AC to keep the rad fan running. Speaking of the AC when I changed the starter I notice the high pressure switch wire harness is missing so I need to figure that out to get AC back. I have changed the switch but it was a "universal" so I am thinking it doesn't work correctly. If I ground the lead it does turn the fan on, so it has to be in the switch. The temp gauge doesn't work even after installing a new switch for that (one from the Fiero Store). And shortly after i got the car the oil pressure gauge started pegging out.
There is also a male 4 pin weather pack connector right next to the thermostat that isnt connected to anything, if anyone knows what that is and can tell me I would appreciate it. I know that in the 80's GM would make 1 harness for all models and only use the connectors the car was equipped with so I am guessing that is the deal here but it would be great to know for certain.
The PO did an EGR delete but did provide me with the original EGR adapter, New EGR, and braided tube. However i was looking at the solenoid and it looks like someone packed epoxy in the lower vacuum orifice so it reinstall I will need to replace that. He said it was his grandfather's car and he doesnt think the ERG was deleted in the computer.
I bought this car to be a project so it looks like I am not going to be disappointed. A lot of this list may not be sorted since in a couple of years I plan to do an engine/trans swap. I am still researching what I want to do on that. I am thinking LLT/LFX with the 6T70E. Or the LZ9 with the 4T75E. I am looking at getting a complete donor car to pull as much from one place a possible. Since I have not seen one completed LLT/ LFX build when I search the forums (though i may be searching wrong) and the last reference to it being 5 years ago I am timid when it comes to that combo. However I do See that BMWGURU did complete a GM HFV6/ F40 swap out of a Saab so I know that it can work but again that was 6 years ago on the 2.8 turbo. I think as far as the tuning goes from HPTuners that 5-6 years should make a difference, but I dont know for sure. I know the easiest rout would be a 3800SC since it is so well documented. I just want to put a more modern engine in. Sorry for my rambling here. My goal is to enjoy this car stock for a few years before I do surgery. I also want to do as little frame cutting as possible, I would prefer to cut no frame at all when the time comes.
The Factory service manual is not as through as I hoped it would be compared to newer cars...
