It's my 1986 Grand Am SE, 3.0 V6, Auto tranny, MPFI. It takes some cranking over and over and over again to get it started. When it starts it idles fine, when I push on the gas, it sputters and struggles to make any RPM's. I just checked the injetors and they all spec out at 16.1 being the lowest to 16.6 being the highest on the ohms meter. I thought maybe the exhaust was plugged up, so I gutted the cat Sunday, it still runs rough. What else should I check? By the way, the car has sat for about two years. It has a new battery and alternator, plugs, wires, and fresh gasoline. I ran a bottle of injetor cleaner in with the ****ty gas to purify it. Should I try that again?

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"Clear your mind, relax, and float downstream."

 

I know I sent you an email about injector resistances, but that doesn't mean they are not bad. Two years of the same old fuel in there, and there is probably alot of varnish buildup inside the injectors and may be stuck open. Does the system loose fuel pressure if you turn it off? Could also be something like a ruptured fuel pressure regulator. Another question: I don't understand the "fresh gasoline" and the "added cleaner to the ****ty gas". Why didn't you put cleaner in the fresh gas and run it? or did you try to clean the old gas with the cleaner? It doesn't work that way, you need to empty the tank and add new fuel, and a botle of cleaner. Start with that.

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"I used to have a handle on life, but then I used it as a plunger and broke it" -The Wave

ASE Master Tech + L1
Savannah, GA
'87 Trans Am-K&N,Cold air induction, SSM SFC, Flowmaster, 16" GTA rims.
'97 Bonneville SSE
About Me

 

86 isn't obd1.

 

Ah........I would beg to differ........

 

beg all you want.

 

2 year old gas?!? Wow, when I totalled my car and it sat for 2 months, the thing wouldn't start... I walked three times to the nearest gas station, filling up my small 2 gallon gas jug- and the car started right up.

-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.v6fbody.com mailbags

 

GMTech, you were right, I tried cleaning the bad gas with the treatment, but I've yet to try putting cleaner in the new gas. I'll try that in a few minutes. Will any type of treatment clean the varnish and remove it completely? Is there anything else I should be checking?

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"Clear your mind, relax, and float downstream."

 

Sounds like the problems my buddy was having with his 88 corsica 2.8 It would idle and kinda run, but if you hit the gas it just wouldn't rev, but owuld kinda flutter when you got off the gas. It was giving him a MAF code, but replacing that didn't help. I think it turned out to be his fuel pump.
ed
ps...Until 96, all GM computer cars were OBD I (all it means is first generation on board diagnostics), then they went to OBD II standards. What the hell do you think OBD I is zippy.

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Ed Maher - Moderator @ the Carb Board
85 Z28 - 357c.i. - stolen 12/24
Click Here for the Rest
'83 Grand Prix - low miles
Only mods...Homemade open element, 2.5" cat and exhaust, CK-B metering
and the way out ******* style in effect
stock 14" wheels w/ wire hubcaps in front
snowflake 15" alloys in the back

 

Ed, not to undermine your knowledge, but not ALL pre-96 GM's were OBD-I. In '94, GM started phasing in OBD-II on the L36 (3800 series) and the LT1(Corvette). In '95, The S/T Utilities (Jimmy, Blazer) also got OBD-II. Then in '96 when it was manditory, everything got it.

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"I used to have a handle on life, but then I used it as a plunger and broke it" -The Wave

ASE Master Tech + L1
Savannah, GA
'87 Trans Am-K&N,Cold air induction, SSM SFC, Flowmaster, 16" GTA rims.
'97 Bonneville SSE
About Me

 

94 and 95 were obd1. the previous years had no name for the system

 

Thanks guys, especially you Ed and GMTech. After some more investigating when I got home from work about 45 minutes ago, I found my problem is a ****ty fuel pump. My pressure is at 14 psi while running. Now I'm burning the rest of the good gas I put in and the STP treatment I poured into it to clean up the varnish.

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"Clear your mind, relax, and float downstream."

 

Zippy, since you don't have a clue, I won't even waste my time arguing with you. You can beleive what you want, but if you don't know what you are talking about, keep it to yourself. I am not trying to be a jerk, just trying to keep the members of this board informed with ACCURATE information, wether it be thirdgen related or not.

P.S. look under the dash of a '94 GM car with the L36 (3800 series motor) and take a peek at the DLC. It isn't the usual 12-pin you are used to, but the 16-pin OBD-II connector. Or just look at a '95 Blazers, it has the same.

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"I used to have a handle on life, but then I used it as a plunger and broke it" -The Wave

ASE Master Tech + L1
Savannah, GA
'87 Trans Am-K&N,Cold air induction, SSM SFC, Flowmaster, 16" GTA rims.
'97 Bonneville SSE
About Me

 

not all 95 blazers had this. some came with the pcm. i have worked on some with the pcm rpo code k29 in the list although they were all 2wd. check your special policy no. 99046. lists it there too. we won't even go into what i know and what you know because it isn't worth it. computer's in cars were introduced in 1981 and were by no means obd1. the obd1 listing is also shown on the emissions sticker on vehicles equipped with it. obd 1 cars were also reprogrammable even though they still have a memcal.

 

also going to check on that L36. i show first year as 95, but going to check on that at work.

 

Sorry, I didn't mean to belittle you, you obviously aren't clueless. 1994 was the GM's first attempt to "phase-in" OBD-II, OK, lets back up even further.

OBD stands for On Board Diagnostics. The very first computers were capable of self diagnostics, hence the name On Board Diagnostics. This started back in like '81 with the Computer Command Control (C3) wich was the computerized carburators. They had very limited diagnostics, did were capable of it, and WAS considered First Generation On Board Diagnostics (OBD-I).

In '94, GM started to phase in the Second Generation On Board Diagnostics (OBD-II). They did this in the 1994 C body with the L36 (VIN L) and the 1994 Y body with the LT1 (VIN P). These were considered partial function OBD-II, since many advancements were made, but still similar to OBD-I. In '95, many more engines were added to the partial function list, and the S/T trucks with the L35 (VIN W) was full function. Some were re-programmable and some were not, hence the K29 RPO. I think the +K29/-K29 seperates the OBD-I and the OBD-II phase in.

If you want more information on it, and you work at a dealership, look around or ask whoever is in charge of training for CPT #56015.10 It will tell you everything you need to know.

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"I used to have a handle on life, but then I used it as a plunger and broke it" -The Wave

ASE Master Tech + L1
Savannah, GA
'87 Trans Am-K&N,Cold air induction, SSM SFC, Flowmaster, 16" GTA rims.
'97 Bonneville SSE
About Me