88 iroc 355 w/vortec lower and slp upper gm hot cam,aftermarket custom accel 24lb injectors,chip vortec heads,--specs tps set @5.8 timing set @ 10 base fuel set @45lbs msd everything edelbrock headders 3' all the way stock fuel pump,anyways i start the car drive down the street,sometimes its a few feet n sometimes its a few miles the car runs normal (but still lacking power) and then bam! it starts to cut out it feels like as if i pulled 4 plug wires off it fights to idel runs really rich has no power n smells really bad! like fuel it chokes me out seriously,everything is new plugs, wires,dis cap,rotor,coil,msd6a, i really cant figure it out codes are as follows 33-36 i have replaced them both about 6 different times it runs alittle better for a day or two then back to ****,on a snap on scanner it shows its lean in that condition when the problem happens the blocklearn is158 and timing is20 normally when the car is in a good mood and no bam problem block learn is 128 im at a loss plz help!!!u can email me @ chrishawkins3143@gmail n i can give u any specs that u need.thanks in advance guys

 

have you ohmed all of your injectors yet? ok.Sure your ecm is good? replaced your cts?

 

i think iwould do the speed density swap! are you sure your ecm is good?

 

the injectors are new 24lb from accel 1 month ago but i had the problem before that as far as the ecm i think so ,n cts? if thats the cat then no,i replaced it 3 years ago n killed it n never replaced it again not until the car runs right.

 

ill get a new ecm n see but i think im just throwing money @it w/out knowing the real problem always the same codes 33n 36 replaced them both same result a couple days later

 

i meant coolant temp sensor. I would seriously consider the speed density swap.

 

Dude, I have a strong suspicion that this is your MAF sensor! gone bad.

 

what needs to be done for the swap tp take place?

 

i can replace its but its always the same result,200$ and 1 week later the same problem

 

the cts reads fine ,the iac can get alittle weird sometimes

 

33 & 36 are both MAF codes. What did you replace in an effort to cure these codes? These codes are related and can be caused by several things. It is almost a certainty that these codes and your drivability problem are related. Search the Tech Articles on this forum for the test sequences for these codes and go through them. Since your problem is apparently intermittent, I would speculate that it is related to wiring and/or connections in the MAF system.

 

i replaced the maf and the 36 relay a bunch of times its ok for a day or two or three then back to running like **** w/ the same codes 33-36

 

I would think you either have a short somewhere, or something is causing it to short or you may have a bad ecm. I guess now it is just a matter of testing the actual maf sensor to make sure it is good still.

 

Plugs gas-fouled?

 

Replacing parts does not necessarily solve anything. As I said, the intermittent nature of the problem makes me think of wiring. Did you find the diagnostic sequences in the tech articles section of this forum? BTW, the "code 36 relay" you refer to is the MAF burn off relay. Go through the diagnostic sequences for both codes. See what that tells you.

Also, "TPS set at 5.8"??? TPS should read about .5v at CT, 4.5v at WOT. Double check that. You may have a poor ground.

 

bad maf? 6 of them? i dont think so,tell me how and i will test the maf

 

no thats really basic but i know alittle bit more about cars than that lol

 

about 5 years ago i paid some guy at an auto eletric shop 400.00 to go thru the wiring for me,w/ no results. the link i did not get but i'll double check,as far as the 36 i can disconnect the maf move it to where i can see it reconnect it turn the key and see the wire get hot,if i disconnect the maf the car runs way worse. if i check each terminal in the connector of the maf w/ the key on what should they read? on a snapon scanner it reads that the maf volts are too high?

 

all 6 of them? the guy @auto zone laughs at me for the fact that i buy these things like candy.....

 

sorry tps is set at .58 does that sound about right,evertone tells me that i should go up to .65,but if i do it idles too high

 

The correct range is .45-.55 so .58 is actually high but acceptable. The code 33 may be a symptom of another problem. Disconnecting the MAF and starting the engine is an old test for bad MAF sensor. If the engine runs okay with MAF unplugged, the theres a problem with the MAF. If the engine runs badly with the MAF unplugged, the MAF is not the problem.

Watch INT and BLM with the MAF unplugged. Do they go high or low? Low means too much fuel. High means too little fuel. If INT and BLM do not function with the MAF unplugged(they may not), use your eyes, nose and common sense to determine if the engine is actually lean or rich. You will need to address your basic rich or lean condition in order to solve the recurrent code 33. Code 36 may be caused by the recurrent code 33.

Keep in mind, an inaccurate O2 sensor can provide false information to the ECM and cause this very type of issue. It may serve you well to test your O2 sensor.

 

Doc, are you sure about those numbers. My 86 FSM shows different numbers, but from all I've read the 86 and 88 call for the same specs.

Jake

 

Yes, Im quite sure. If your 86 servce manual says otherwise, youre either reading it wrong or it's a misprint. Through 1989, all GM TPSs were set at .5 +/- .05v that equals .45-.55v. In "90 GM began using a non adjustable TPS and self calibrating PCM. The voltage range on the later type of TPS is generally .20-.90 and is, again, non-adjustable. It is important to note the difference when servicing GM vehicles around this year range.

However, as I said earlier, .58 should be fine. I don't generally notice any difference between .4 and .6.

If I wasnt clear, let me expand on my point. Your symptom could very well be caused by a faulty O2 sensor. In fact the connection to driving "a few feet or a few miles" sounds very much like a bad O2. Another possiblity is the CTS but not as likely in my opinion.

Keep in mind, these early ECMs aren't too swift. It is fairly common for them to set a code for MAF or MAP or to set no code at all when in fact the fuel trims are way off and by no fault of the MAF or MAP. These systems rely heavily on CTS and O2 data for fuel management and do not recognize in-range failures of these sensors.

Use your scanner to perform an O2 sensor test. Watch for O2 voltage to hover on the low side of .450 rather than toggle quickly between .200 and .800 as it should. Compare CTS data to actual engine temp using an infared thermometer. Does CTS data make sense? Or is it way off?

 

.54 (+/- .075) Others can do the simple math to determine the range.

Page 6E3-A-40, paragraph ".2 TPS adjustment: With the throttle closed the TPS voltage reading between terminals A & B should be between .54V +/- .075".

This was taken directly from the GM Corvette Service Manual, but since it's for Corvettes, I can only assume 'F' body cars are different. In any event, it's not a point worth futrher exchange.

Jake

 

Reading through your thread I noted that you paid someone to go through your wiring. Its vital that any engine/fuel injection wiring be performed using solder and heat shrink. A tech must also be skilled at soldering and perform this properly to insure good connections that continue to peform well over time. For heat shrink I prefer the marine grade as it is heavier and contains a hot melt sealant that creates an air tight seal around the joint. Use of butt connectors is not okay. If your system contains any butt connectors, suspect them of high resistance. Especially if theyre more than a few years old.