I've rebuilt a 2.9L V6 and I have a stange problem I cannot figure out. When I try to start it, it will pop a few times then it wont do anything else. It appears to be flooding out because when I unhook the fuel pump relay, is begins firing. I hooked up a multimeter to my self test connector (KOEO) and it appears I am getting codes 11 and 96. ...1..1..4.sec..1..1..4.sec..1..4.sec..9..6..4.sec ..9..6..........
I believe the 96 is throwing because I do not have a fuel pump monitor. 11 is system pass, does this mean something didn't pass, or does it mean everything passed? Me and my friend also thought it could have been weak spark. We have a MAC timing light that hooks onto the spark plug wire, and it isn't showing anything. We have an inline light that hooks up to the spark plug, and it shows it's firing... When it does fire, flames come out of the exhaust. We don't think the timing is off, we've put the rotator on plug 1 when the engine is at TDC. Also has been checked several times.
I've done the MAF conversion, using a 1990 computer in a 1988 Ranger. I used a 5.0 MAF and 19lbs injectors. This has been done before, and it seems like everything should work, I am not sure if it's related to the MAF conversion. Any ideas?!?

 

There are three types of codes output by the EEC-IV computer: KOEO, KOER, and continuous memory (CM). In your case, the 11 is the KOEO codes, which means it passed that portion of the test. You can't start the engine to run the KOER test. The 96 is a CM code. I expect it was set when you tried starting the engine with the fuel pump relay disconnected. If you really didn't have a fuel pump monitor circuit, you would get the 96 as a KOEO code as well. Clear the CM codes and see if the 96 goes away.
I'm not familiar with the MAF conversion, other than I know it can be done. I wonder if the 5.0 MAF is too big. The signal from the 5.0 MAF requires a different calibration. This could mean that your 2.9 computer is calculating a huge amount of air from the 5.0 MAF signal, which causes it to dump a huge amount of fuel into the cylinders. I really don't know. You'll probably have to find someone who's put a 5.0 MAF into his 2.9 to see how well it worked.
You might try unplugging the MAF and see if it starts. Unplugging the MAF causes the computer to "guess" a reasonably value for the MAF output, which may allow you to start the engine, even though it might run rough.

 

I really appreciate the response. There's a bunch of Carbed Chevy lovers where I live, and no one really knows about EFI. (Indiana) I get dissed about my Ford Ranger always, but it's a nice truck. I think it's because we have a GM plant in Fort Wayne and one about 1 hour away in Defiance Ohio. Anyway, I have tried to unhook the mass air, but it could have been flooded at that point. I'll try it again. I am going to go to the junk yard and try a mass air from a 3.8L V6. I think you're absolutely right, I talked to a technician from IST (They made my air adjuster), and he said it was a calibration problem. He said that the computer is calibrated for 14lbs injectors, and the mass air is calibrated for 5.0 19lbs. I am just having trouble visualizing why the signal would be so hot from the the MAF, I suppose the ECU could be expecting some much lower just in general. Perhaps I should try to get a MAF from a 1990 Ranger, but they're difficult to find. I'll let you know if I can get it running.

Thanks,
Pete

 

Another possibility regarding the ECU. Again, I'm not real familiar with the MAF conversion, but most '90 2.9's would be speed density like your '88. As I understand it, only California models came with the MAF. If you're looking for a used MAF, maybe try some yards in California. I see that Autozone offers reman MAF's on their website.
And lest we make too many assumptions, are you certain the '90 computer you got is for an MAF 2.9? If it is an MAF computer, I'm not certain why your supplier shouldn't be able to get the accompanying MAF. If it's a speed density computer, however, it will be trying to use the signal from the MAP/BAP to set mixture.

 

Yes, you care correct about the ECU being for Californian Rangers only. I bought a used ECU from a company who parts out Rangers in Southern California. Fortunately the MAF instructions supplied the part number for the ECU. I think I goofed up and bought the wrong MAF meter. The correct one is a lot smaller. The one I have now may have been from a 5.0 HO. I ordered a new old stock MAF off of ebay. Hopefully it will be here by Monday or Tuesday.

Pete

 

MrShorty, Thanks for your help. My timing was 180 off. We set it on #1 when the piston was a TDC. My brother came over and we found out where the piston should be firing. We pulled off the distributer cap, and it was 180 off. We adjusted, put back in, and it fired right up! Sounds like a little dragster with that custom ground cam and pacesetter headers. BLUP!BLUP!...BLUP!BLUP!...BLUP!BLUP! It's smooth, I was suprised the Mass Air Conversion worked, as well as the air adjuster. It was running lean, but I think that was from using a MAF from a 3.8 T-Bird. It's bigger, and is probably calibrated for bigger injectors. I'm just glad it runs and I didn't have to part it out. However, I was offered $3000 for the truck not running. It's in really great shape, especially with that nice rebuilt motor. I had it repainted a month before it died. Next step is to put on a 65mm mustang tb in place of my 58mm and put the 19lbs & 5.0 MAF back in. I think the 14LBS injectors are going to bottom out, but only time and my air fuel meter will tell.

Pete