benscool1

OK, I've got a 305 and 700r4 from an 86 Iroc, currently with edelbrock carb and intake. Pretty much nothing from the orginal wiring is hooked up including O2 sensor, EGR valve, hell, all the emissions stuff is totally gone along with he computer.

Now, I've replaced plugs, fixed some wiring, new fuel filter, new vacuum lines, adjusted my carb, adjusted my TV cable to specs and finally my car will idle right. But when I step on it it will not spin the tires on the road. Plus when I stomp on it, it doesn't feel like it downshifts right all the time, even though I've adjusted and re-adjusted the TV cable numerous times. Why would it do this? Could it be a carbureator problem still? Too rich or too lean? It idles good and everything but doesn't seem to have as much power as I would expect. My 84 Scottsdale w/180K on the 305 would run better than this, even on 7 cylinders. I have yet to do a compression test but it runs fine at idle so I didn't think it was necessary? I just can't figure out why it would be running like this.

BTW, yes I did search.

84z28350

I hope your not trying to use the same cc dizzy that came with that engine...

What color are the plugs?
any smoke at WOT?

PhLaXuS

Could be spark timing. A very retarded timing will cause these types of problems.

benscool1

cc dizzy? I can't honsestly tell you exactly what has been done to the car, according to the PO who did the engine swap(was originally a 2.8) the motor and trans came out of his cousins wrecked Iroc w/less than 1K on it. Now the trans and engine has 42K. I was told it had a "nice" distributor on it, and when I asked him what kind it was he said "I think its an MSD" I don't think it is an MSD because the plug wire retainer(whatever the thing on top o the cap is that holds down the spark plug wires) says Delco Remy on it. I do have an HEI distributor out of an 81 Chevy truck, do you think the distributor might be the problem? I've checked and reset the timing and it is correct now. What do I need to look for to tell me its not the right distributor?

BTW, the old plugs were black when I changed them and didn't look fouled or anything. No smoke at WOT. I adjusted the timing by ear first then got out a light, then had a professional mechanic do the same just in case I wasn't good enough. Timing should be OK.

Fast355

iTrader: (2)

A plugged cat, a self desintigrating muffler, and just the stock F-body exhaust in general will do this.

Token

Your problem is very obvious. You have an anemic 305 born in the 80s.

benscool1

A plugged cat was something I was wondering about, after running for awhile I can smell something a little funny. It also crackles a little bit when I rev it up. It has a flowmaster muffler but I'm not sure how old.. Is there any good way to see if my cat is plugged? If so would I be better off replacing it w/one from Advance or putting in a straight pipe?

PhLaXuS

So true...so true...I can only say this because I, too, am running an anemic 305.

Token

swap asap

Fast355

iTrader: (2)

Workover the heads and put a decent cam in it. Then open up the exhaust. Your 305 won't be anemic anymore.

As far as the exhaust, just check the backpressure on it. I use a vacuum/fuel pressure gauge, hooked to an AIR fitting. Usually take the check valve off and measure there. I like to see no more than 2 lbs @ 3,000 rpm.

This part is long but, don't forget that the 1983/1984 LE9 305 truck engine made between 170 and 180 HP @ 3,800 and 250 ft/lbs @ 2,000 net rated. They are much stronger than any stock LG4 as they are in the same class as the L69. They have better timing curves in the distributer than cars (granted I am talking about in the EPROM in cars) and came with better carb jetting stock. The truck intake and exhaust are less restrictive as well. Trucks/Vans got the L69 cam instead of the weakling LG4 cam as well. The compression was higher at 9.3:1 with steel shim head gaskets. A final addition was the 14022601 heads which flow somewhat better than the 416 car heads.

The LE9 will typically dyno about 150 RWHP and 230 ft/lbs of torque stock. A LG4 on the otherhand is lucky to get 125 RWHP and 200 ft/lbs.

Here are the DD2000#s for the LE9 vs. LG4

RPM------HP(LG4)TQ--------HP(LE9)TQ
2000----114------300------112------294
2500----144------302------144------302
3000----170------298------178------311
3500----183------274------204------306
4000----182------239------221------291
4500----164------192------229------267
5000----134------141------222------233
5500-----96--------92------203------194

Just improving the LE9 vs. LG4 comment. I have a datalog from a 1984 suburban swapped to TBI otherwise stock LE9 305(new high flow cat and flowmaster) /700r4/3.42 gear that I tuned for a friend of mine. Engine is stock spec rebuild displacing 310 CID w/ stock cam, stock heads, stock type .030" over piston, Holley Projection manifold & 1 " TBI spacer for IAC to EGR valve clearance. Clipped section of WOT acceleration. Info is 1.2 seconds between. That makes 30-60 about 9.5 seconds but what do you expect for 180 HP/250 ft/lbs moving 6,000+ lbs of 4x4 suburban.(A new 5.3 w 290 Net Hp moves a 2wd reg cab truck 40-70 in about 6 sec) This 4wd averages about 16-18 mpg now.

MPH-----MAP------RPM-------TPS------BLM
48-------27.3------1450-----(-1.7)----128
45-------28.4------1325-----(-1.7)----127
41-------29.5------1225-----(-1.7)----126
37-------31.8------1175-----(-1.7)----116
32-------29.9------1200-----(-1.7)----114
28-------28.8------1200-----(-1.7)----114
27-------30.3------1175-----(-1.7)----128
26-------96.3------1925------56.7-----126
29-------97.8------3150------96.8-----126
33-------95.6------3975------97.3-----126
40-------98.2------2850------97.3-----126
43-------97.8------3125------97.3-----126
47-------97.1------3300------97.3-----126
51-------96.3------3725------97.3-----126
54-------97.1------3925------97.3-----126
57-------96.7------4175------97.3-----126
60-------96.0------4400------86.6-----126
61-------83.4------2275------37.9-----117
63-------60.2------1825-------9.9------108
62-------36.6------1825-------6.5------108

Fast355

iTrader: (2)

Double

benscool1

Well what can I do to fix the problem without rebuilding or swapping my engine? I realize its just a wimpy 305 but my buddy's bone stock 88 305 w/TBI had waay more miles and would still break the back end loose without even trying. I'm not going for a 11 second car, hell I'm not even going for a 15 second car, just something that'll be fun to drive once in awhile.

Fast355

iTrader: (2)

I think we have already established this engine has some tuning issues as my bone stock LE9 would spin 255/70/r15s with 3.08s and had the stock 1,600 rpm Torque Converter in my van. That and notice how well that 6,000 lbs suburban moves with a stock 305.

Well what Edelbrock Carb and Intake is on it. Does the throttle linkage fully open the throttle and the secondaries? What about your distributer? Do you still have the stock computer carbed distributer on it. If so your timing advance is now 0* which would make sense for NO power. Make sure your distributer has vacuum and centrifical advance mechanisms. Then set your distributer up to give 32* total advance @ 2,800 rpm and about another 15 vacuum connected to the manifold fitting. Then read your plugs to make sure that your carb is delivering the proper air/fuel mixture. Check your exhaust backpressure to ensure your exhaust is not restricted. Make sure your engine is getting ample fuel, best way is check the pressure under load. Make sure the engine is in a good shape of tune. Make sure you have good compression by doing a compression test.

It might pay for you to have your car dyno tuned. I have seen many cars have good gains in power, mileage, and driveability from a simple dyno tune. They can establish timing and jetting for the best of everything by loading it on the dyno. Wideband in the exhaust and then vary the timing for the most vacuum under a certain load. How do you think my G20 can make 270+ RWHP and still get close to 20 MPG highway.

Finally you can change your exhaust system from the exhaust ports in the heads rearward. Headers, High-Flow cat, bigger pipe, good low-restriction muffler.

darkecho

definately check the muffler..

my car had the same problems, no power, wont down shift

until one day i floored it and heard a loud explosion and saw grey smoke everywhere in a giant, cloud, went back to look... smelled like burnt rodent... so i assumed that my car just shat out a rat... i cut off the exhaust before the cat so its running open Y pipe right now and i can easily break traction, HUGE difference!!!!!!!!!

PhLaXuS

I just about lost it! That's so hilarious!

firebird45331

friend got a mustang that sat out a field for awhile did the same thing exhaust note changed then boom out came a rat from his flowmaster

PhLaXuS

So I guess the moral of the story is if you're gonna park your car for a while where small animals can get in, place metal screen around the end of the tailpipe and hose clamp it in position.

When I was 3, my mother had a Maverick and I remember it stalling out while goin up a hill. I was told someone smashed a potato in the pipe.

benscool1

Ok, I'm gonna replace my exhaust then, should I put a straight pipe in place of the cat, get a stock replacement cat. or get a high-flow converter from summit or jegs?

84z28350

Your going to need the cat if you plan on easily passing emissions. If i were you (and gladly im not ) i would grab a high flow cat and throw it in there.

del91_305

I am haveing a similar problem, mine was a 305 TBI, and i swapped cam, heads, RPM intake and 1406 carb. I was checking the valve lash to find out that some of them were way too tight. I hopeing that this may be part of my problem

benscool1

Luckily I don't have to worry about emissions tests here in IL. The car back to running badly like it was when I first got it. It will hardly idle and now it has a miss. It was going good until I let my dad drive it tonight to see if he knew what might make it feel sluggish. Any ideas on that one? BTW, how can I tell if I still have the computer carbed distributor?

dimented24x7

iTrader: (2)

The non-CC HEI dist. will have a metal vacuum can for the vac advance hanging off the side of it. The CC-HEI dist. will just be a plain dist. with nothing on it and a remote mounted coil. There will also be a 4 wire connector at the base of the dist. for the ecm to hook into. Definatly want to ditch it if you have a carb with no computer.

dimented24x7

iTrader: (2)

Also make sure that the TV cable is TIGHT when you hold the throttle all the way open.

benscool1

Yeah, I've got a non CC distributor w/vacuum advance. No problems there. But I took the dist. cap and rotor off to inspect them to see if that might be part of the reason it suddenly started running badly again. Well when I replaced them and plugged the clip on the dist. cap back in it friend the ground wire from the neg. battery cable to the fender as well as the wire to my aftermarket oil pressure gauge under the dash and started a fire. At this point I'm just really frustrated and am not sure what to do, its not getting spark and it just keeps frying that auxilary ground wire to the fender. What could be the problem there? I talked to a guy tonight who said the only reason it would do that is because the main ground cable isn't getting a good enough connection and I also needed to check a white wire that plugs into the distributor? If that didn't work I need to check a couple fuses. Does that sound like the right thing to do? It was dark and cold out by the time all that happened so after screwing with it for about an hour and a half I just got fed up and called it quits for the night.

84z28350

Im not sure how you managed to catch various parts of your car on fire unless you hooked the tach and +12v wires backwards on the cap but i dont think that would do it though.

PhLaXuS

And moreso, to burn the ground wire from the battery (-) to the frame would take more than a small amount of current!

benscool1

I couldn't have hooked them up wrong, the battery wire didn't come out and the other clip w/3 wires that connects next to that only goes in one way, I don't understand what the hell happened? I was so pissed I couldn't even see straight so I just had to stop before I broke something worse. But I guess this is part of what comes w/buying a $600 car that some dumazz crack addict tried to put together right. I guess I shouldn't have expected any more than that.

Edit: Actually the tach wire didn't even come all the way disconnected, it was still in there just pulled out a little bit and I pushed it back up in. Now when I turn my lights on my tach winds backwards until I turn the lights off....