Starting problem. Flooding?

OK, so I took my ’90 to the shop because it will start occasionally. By that I mean; it could start on the first try, or the 5th, I never know. I had them check the cam sensor and pull the codes. I got 67, 82, 88, 19. They thought the car was flooding because of all the black smoke that rolled from the exhaust from the combo of mods done to it.

There are some previous mods done to the car (not by me, I bought the car on Wed). Looks like a 76mm maf (cant tell what tube is in it, no color) 70mm throttle body, 42# injectors. Also, the part that the TB bolts to looks to be aftermarket, as it is a slightly different color, and it has a weld about 2.5” underneath the paint/powercoat. With the car I got a 1 ¼ raised top that could have been on the car at one point because the nut on the regular top that is on now it pretty beat up.

One of the mechanics thought it was the maf that was messing things up. It could be if the sampling tube isn’t matched to the injectors, right?

Anyways, the car runs great otherwise with a lot of power. It is just this darn starting problem that is driving me nuts. I don’t want to be stranded somewhere if it wont start.

PS. I don’t have any stock parts, what is on the car is all I have.

I hope we can resolve this.

Thanks guys,

Kyle

Viewed from the TB side, the sample tube should be purple. If there is no color on it then you may need to measure it with a caliper.

Does the car have a chip? If not, you need one. I can't tell you for sure that not having a chip is your entire problem but it sure won't help things.

No color on the tube. I dont have a caliper, could I use drill bits to see what one fits (being careful of course). No, the car doesnt have a chip from what I can tell. But I might be interested in one after I get the starting problem fixed.

Or do you think my starting problem has something to do with not having a chip?

OK, I got the purple tube. How do I go about getting the computer to "learn" that it has the new sampling tube. I have the battery disconnected at the moment and will leave it that way overnight. Will driving it to work do the trick? It is about a 12 mile drive one way. What if that doesn't fix my problem? Lets hope I dont have to cross that road, but who knows...

theres an article in the lit section on the front page, about the procedures for relearning your computer.

Cranking fuel delivery is set by a fixed injector pulse width and nothing else. So when you start cranking, the computer sends a pulse width to the injectors to open them, and that pulse width is based on a 30# injector, so put a set of 42's on and your sending the same pulse width and you just put almost 29% more fuel in. Most stock cars are probably ok with it.

Only a chip can fix that. No amount of relearning etc will take that startup into account.

Fraser

OK, so I installed the purple tube and the computer has had time (about 150 miles) to learn. Problem is still there. After thinking back on it, the starting problem is more prominent when the car is warm. 1-3 tries when cold and 2-6 tries when warm. Now, do you think that it’s time that the car NEEDS a chip? Can a chip change the parameters when cranking so I don’t get so much fuel? What if I want to do some exhaust work and add a double IC? Should I do that before the chip?

Kyle

It depends on how much moolah you want to spend.....

Switching your injectors back to 30# might help, but then your 70mm TB and 76mm MAF might give you some problems.....

Getting a chip will definitely will help your situation.....

Just a thought, but don't you want to match the TB and MAF sizes.....

I bought the car exactlly the way it is (except the purple sampling tube). I know that I would have done it differentlly if I had done it.

kylecoz88 said:

Now, do you think that it’s time that the car NEEDS a chip?

Click to expand...

Have you checked for a chip yet?

the-big-e said:

then your 70mm TB and 76mm MAF might give you some problems

Click to expand...

Why would the TB cause any problems? If he got a sampling tube for 30's and installed 30's, that combo wouldn't hurt anything.

the-big-e said:

Just a thought, but don't you want to match the TB and MAF sizes.....

Click to expand...

You better ask that same question to at least 100 other members out there.

I just asked the question because I had an SC come into my shop that was running rough under boost.....

The owner had a larger aftermarket MAF on it.....

I swapped an OEM one in its place and his SC ran a whole lot better.....

I am under the impression that you should match the MAF and TB as close as you can.....

Am I wrong......

The way I am reading this is he is running 42# injectors while the SCs computer thinks it still has the 30#s in it....

the-big-e said:

I just asked the question because I had an SC come into my shop that was running rough under boost.....

The owner had a larger aftermarket MAF on it.....

I swapped an OEM one in its place and his SC ran a whole lot better.....

I am under the impression that you should match the MAF and TB as close as you can.....

Am I wrong......

The way I am reading this is he is running 42# injectors while the SCs computer thinks it still has the 30#s in it....

Click to expand...

I'm gonna take a stab here and say it would make sense to keep them the same size or close too for the purposes of air flow...Meaning why install a 90mm Maf and keep the stock 55m throttle body.

Outside of that I can't see any other purpose except bottlenecking the intake side of things.

As mentioned above, I would also suggest a chip to correct the rich issues...sure it has a lot to do with your troubles.

-Tim

the-big-e said:

I am under the impression that you should match the MAF and TB as close as you can.....

Click to expand...

I agree. But having them this way doesn't cause the car to run bad.

the-big-e said:

The way I am reading this is he is running 42# injectors while the SCs computer thinks it still has the 30#s in it....

Click to expand...

The 76 mm MAF with a purple sampling tube is supposed to tweak the voltage reading from the MAF so that the computer compensates for the 42's.

IMO anytime someone changes injector size or MAF they should have the car tuned.

no chip, see pic. Also there is a spliced wire in the engine compartment (again, see pic). It is a bare wire with no coating. I think I saw this wire grounded by the computer??? I also have a pic of my inlet plentum. Take a look.

Seems like it is chip time. Do I contact XR7Dave with a list of my mods?

90blkbrd said:

I agree. But having them this way doesn't cause the car to run bad.




The 76 mm MAF with a purple sampling tube is supposed to tweak the voltage reading from the MAF so that the computer compensates for the 42's.

IMO anytime someone changes injector size or MAF they should have the car tuned.

Click to expand...

The MAF does like you said BUT not at startup when cranking. The MAF voltage has nothing to do with injectors during this mode so there is no compensation. It is like I described above. He's getting 29% more fuel per injector pulse when starting.

Fraser

kylecoz88 said:

no chip, see pic. Also there is a spliced wire in the engine compartment (again, see pic). It is a bare wire with no coating. I think I saw this wire grounded by the computer??? I also have a pic of my inlet plentum. Take a look.

Seems like it is chip time. Do I contact XR7Dave with a list of my mods?

Click to expand...

Either buy a chip from Dave or Fraser, or do the fun thing and buy a quarterhorse and learn to tune on your own. It's not as hard as you would think, but it's not easy...I think either Dave or Fraser could still set you up with a base tune with the quarterhorse...It's also probably more expensive, but it's worth it in my opinion....

It looks like you may have a rather modified inlet plenum and blower as they seem to match color to each other but not the rest of the parts. If it were me I'd be curious enough to take them off and open it up to see. It may be one of the early ESM systems.

But more to the point you have a code for a bad cam sensor. If you did not replace that already, do so now. Also, a chip would be a very smart idea at this point.

I just looked through the old receipts that the car came with and I found. crank sensor, cam sensor, harmonic balancer puller, starter selinoid, starter and a bunch more stuff that doesn't apply to the starting problem. All of that stuff was new within the last two years. So I will assume that nobody has been able to fugure this out.

Also, my tach doesnt work - is that directly a result from a bad cam sensor? (the previous owner had replaced it) or could it be in the wiring?

I will try to replace the cam sensor to see if that takes care of the code.

Dave you were right. Check out the warranty card that was with all the receipts.

I replaced the cam sensor and took a pic underneath it. Is it alligned correctlly? How it is in the pic is how it was when I took the sensor off and I don't know how to adjust it, so I just put the new one on.

Anyways, the starting problem is exactlly the same. I'll run to AutoZone and see if they will pull codes for me.

(EDIT)

Code results (KOEO)
82
88
19 - No power to EEC processor or failure in PCM internal voltage??

Also, my tach still doesnt work. I though the cam sensor might have fixed it

Has the DIS module been changed....

It's the gray module on top of the jack shaft bracket and near the A/C compressor.....