ajw9301

So I have an 87 c4 I bought about 2 months ago. 81,100 Miles. Drove fine first couple rides (although service engine light was on) car seemed to run amazing. One day car lost power when I was at a stoplight had to get it towed home a couple miles.. I removed air duct and what not and checked fuel pump with starter fluid when I got it home. To make a long story short I had fuel pump replaced/strainer and the wiring harness for it under engine compartment (it was shorted/fried out with bare wires near the top of relay. I also replaced all of the fuses I had 1 fuse that was cracked/metal broke off. ( I still have all the old fuses just incase? lol)

Car drove fine for about 10miles then died out on me again. Im guessing I have more than a fuel pump issue obviously? Seems to be something electrical possibly? bad ground wire? I am not too sure. I have checked fuel pressure it is fine (40 Key on 38 when Idling). (I do have a very slight oil leak) Ive ran codes on it by using a paperclip and turning ignition on of course etc. Video I recorded of the flashes Code 13 an 36 Is what flashes I believe? correct me if I am wrong.
I noticed the car also has a surging idle it idles very weird sometimes up to 11-1300 RPM?

Main problem is that I am a truck driver and I rarely get time to work on the car when I am home. Just really frustrated I would like to get it up and running already instead of covered in the garage .. Any insight would be greatly appreciated.

antfarmer2

Check it for fuel and spark and let us know what is missing. Look for vacuum leaks and smell for fuel in the FPR vacuum line.

ajw9301

Ill be honest with you im not very mechan savvy so I have no idea how to even look for vacuum leaks and smelling for fuel in FPR vacuum line? how does one accomplish this lol (appreciate the help!)

also is it possible the VATS can be preventing car from starting? a friend mentioned I should try getting a replacement key and seeing if that helps (since its a simple solution)

Cliff Harris

If you have a VATS problem it will set error code 46.

For the error codes for your car, check here:

https://www.corvetteforum.com/forums...post1576116036

exitwound

Hi..

What codes are you getting?

I would check that you have around 40psi fuel pressure (there's a Schrader valve for this on the fuel rail just in front of the distributor on the passenger side). If the pressures ok when your idling, then fuelling/pump is ok.

A dodgy MAF (between the air filter and the throttle body) could cause poor running like this, disconnect it and see if its any different to drive.

Ignition.. Could be a bad distributor cap or rotor, or even the HEI chip inside the distributor which can fail when it gets hot.

Vacuum.. In front of the distributor, on the passenger side of the top plenum chamber, there are two vacuum ports. Trace out the lines coming from these and make sure that they are connected to something. There's a larger one under the drivers side of the throttle body too, check that. Basic rule of thumb here is that if you discover any disconnected vacuum lines and you aren't sure, just block them and see how things run (apart from the big one that goes to the brake servo).

The vacuum line that everyone forgets, runs behind the distributor and is buried down the firewall. This line controls your heater/demist/vent function, so to check its ok, get in, run the motor, and move the control setting and you should feel the fan difference at each of these points. If they all blow the same no matter how you set things, then the vacuum line is not connected. its a pita to locate, but it's down there.

As I'm in the UK, I don't need the emission controls so I have removed all vacuum lines off my '87 except the vent control and the one that goes to the fuel pressure reg. (right under the plenum in front of the distributor). I have simply pulled the hose off the EGR (in front of the FPR), dumped the charcoal can etc, and the A.I.R. and all its switching and vacuum pipes. Also lost the cruise control gear, and it runs perfectly.

None of this stuff is difficult to check out, so good luck..

ajw9301

Thanks I will check all of that from the video I posted above? It seems that is a code 13 and code 36? correct me if im wrong

ajw9301

UPDATE: 6/29/2016
Replaced MAF burnoff relay & power relay
car started ran good but died after 5mins. Will not start again. Checked codes code 13 & 36 is no longer flashing but check engine light still comes on?

Next step I am taking is replacing the MAF and ECM. And the spark plugs & wires.(Most likely the ignition also?)
Anyone have a list of tools I need for the plugs? I know I should have most everything just have to pickup some deep sockets cause I know I don't have any just need to know the sizes I need.

Also a quick question my dash reads 12.0 volts when car is off is that enough voltage to start the car? doesnt seem like enough to me is it possibly alternator is not doing its job? This battery is brand new from autozone (under warranty). I know it should be 13.8-14.3v when running?

Tested if it is a spark or fuel problem again by spraying starter fluid into throttle boddy area and it turned over and wanted to start so its Obvious im getting spark. Debating if the fuel pump job I paid for at a mechanics shop down the road did a botched job? (I was referenced to take it there) Didn't have time to do it myself. Car drove fine that day I went to pick it back up. Had no issues on the way home. Couple days later tho it died out again (back to step 1) Assuming the fuel pump job wasn't botched my last resort is testing the Icm/coil im guessing?

Chris Rolewicz

Have you tried putting the key in the ignition and starting it?

ajw9301

Funniest thing i've read all day. LOLLL

Dt86

Did you clear the codes stored in the computer? If not I would do that and see what you get. Can you hear the maf burnoff taking place after you shut the car off? You might try spraying the maf out with maf sensor cleaner before buying another one. Have you checked your O2 sensor wire for damage?

ajw9301

How do I clear them again? disconnect battery for 30secs? and no I have not checked 02 sensor wire where is it located?

Cliff Harris

You reset the codes by disconnecting the ECM power connector for 1 second or more:

ajw9301

thanks! should I have the negative battery terminal disconnected before I disconnect that? Or do i not have 2 bother

ajw9301

[QUOTE=ajw9301;1592532048]thanks! i reset the codes and tested for codes again. Seems to me that there is no codes anymore. just the normal code 12 flashes. do you think it may be a ignition problem since my fuel pump/strainer has been replaced already?

ajw9301

Upon further inspection i noticed I have some sort of cut line? (driver side in front of alternator/below it?) and 2 lines not plugged in 1 that runs to alternator i believe? here are pics

kael

I've had code 36 for a long time (on my '87 ), that won't cause what you're seeing. Don't get a MAF yet, there's diagnostics in FSM (field service manual) to run through first.

Oxygen sensor will be a huge problem, get that fixed first.

Some codes only show up after certain conditions, example, the code 36 doesn't show up until car has gotten up to temp and turned off, next start it shows up again.

One important question, you're using NON-ETHANOL premium fuel, right? If not, will mess up the engine performance big time. I learned the hard way and ended up draining 15 gallons from my fuel tank.

Aww, you're PO took your engine emblem too? Mine too. Buggers. Oh well, $40 fix.

ajw9301

Thanks kael. Quick question when I bought this car I noticed the exhaust isn't the stock exhaust system? is it possible they removed the catalytic converter and o2 sensor?
Went out checked fuel pressure today 40 Psi on with key to "run" and 38 psi when car is started and idling (was honestly surprised car started). Ill be removing the oxygen sensor soon and replacing it (if its there? Lol). And as fuel goes last time it was filled up wasn't by me im not sure what was put in it, regular unleaded i'm guessing facepalm lol. Might be a good idea to drain it and put premium in eh? Im starting to think I have an intermittent ground problem? sometimes car starts other times it doesnt want to start just cranks? or will a bad ignition/distributor have these symptons or an injector not firing? Im clearly getting spark and fuel/fuel pressure fine. I have no clue as to how to check grounds tho. I suppose I will be doing a lot of reading lol

ajw9301

Removed Maf Sensor and cleaned it with maf sensor cleaner and let it air dry. Will be checking o2 sensor next. Also probably going to be replacing battery terminals with new ones they look ancient and Im hoping it will fix my low voltage problem? Car drops to 13.2-13.6volts sometimes when running. Other than that replacing maf burnoff/power relays and cleaning Maf has seemed 2 fix my check engine light no longer comes on and I have no codes . Still have a funky idle (I will record the way the idle runs tomorrow) but hoping thats from o2 sensor or idle needs to be set right?

ajw9301

I took off FPR vacuum line and smelled had a very faint smell of fuel? is the next step taking everything off to check for fuel inside of plenum? if so what about after that? checking the fpr/diaphram? or should i just disconnect vacuum line to fpr and see if fuel comes out while its running?

yd328

I would do some basic maintenance to the car. If this hasn't been done already, change the plugs, cap, rotor, wires, and o2 sensor.
Also clean out your throttle plates and iac valve, this alone may help with your idle. If you can get a factory service manual, not a chiltons.
As for that scotch locked connection in the picture, get rid of it. Solder and shrink wrap the connection. Those connectors alone cause a lot of issues.

Gary