1991 Camaro 5.0L TPI Rough Running, Long Crank, Burns oil... (Page 1/1)
Racing_Master MAR 12, 10:55 PM
WELL! I believe I know what the main problem is, but let's see what everyone else thinks as well! History on the car:

this 1991 Camaro was my first car when I was 16... 3 months later I blew the engine up in it. it was a V6 3.1L that spun a bearing (big surprise!). Well I swapped the engine for a free 5.0L block and I had found a TPI setup in a junkyard. I never serviced the TPI setup, the injectors were the ones right from the junkyard, not cleaned. just threw it all on! I also never did the rings in the free engine, just threw it all together. I did, however, change the bearings.

I also swapped the transmission from a 4 speed auto to a 5 speed manual, switched the dashboard out with a TRans Am Dash... all the fun stuff. A lot of work for a 16 year old! Well this monstrosity has never driven right, since, well, it was built by a 16 year old that just was getting into cars and had NO CLUE what he was doing on a project this scale, with no help. It does run and drive, just not... right. no power, engine misfires, etc etc.

Onto the main problem. the Cold Start Injector was unplugged because for some reason it's shorted in the on position and drains battery (YAY 16 year old's wiring!), so without a CSI, I know it will crank more... The engine's TPI is from 1986, the computer is from a 350 firebird from 1988. I think in 88 they switched to no CSI, and since it's a 305 vs a 350 my fuel tables are gonna be a bit rich I think, but anyway. I crank it, and it doesn't fire right away... turns over for 10 seconds or so, then catches, and stalls. Turn over a bit more, catches, stalls. pump the gas while cranking it catches.... catches some more... slowly catches more... then VROOM fires up. It then proceeds to idle, high idle, until it's warm. It's idle is still kind of high at 900rpms when at warm idle, which tells me I may have a vacuum leak, but that's not the biggest issue on my plate here.

It keeps fouling out cylinder 3, bad. Before I used to clean the spark plug, and okay it ran what seemed okay at the time, still hesitates on rev, still runs a bit rough when cruising in low RPMs, and still no balls to it. I changed: Spark plugs, spark plug wires, cap, rotor, and coil. checked and set ignition timing with a digital advance timing light both at idle and at higher RPMs checking mechanical advance function. I also have run lots of fuel injector cleaner through the gas to try and clean the injectors out. It burns oil under acceleration, and on first start. All spark plugs appear fine but Cylinder 3.

The other day, I got it back on the road, and it ran like crap again, Cleaned cylinder 3 spark plug, cleaned out the cylinder as best as I could, let it sit with some penetrating oil in it to try and lubricate the rings, and I drove it home. Upon going home, on the way, I started having a dead miss. What cylinder? cylinder 3. I checked compression and it has a great 175psi of compression. Since the spark plug is as clean as I can get it, and all the other issues, I have to say my old injectors are all kaput, no? Lack of fuel, running rich smelling, Hesitation, long crank, etc etc, all seem to point to injectors. Anyone else have any thoughts? I just bought all 8 injectors from rockauto for only 25 bucks each!
Joe 1320 MAR 14, 10:29 AM
A leakdown test might be more of an indicator of the overall health. I know that when my CS injector went out, it was a bear to get started as well. It probably has tons of miles on the injectors so it would be a good idea to replace them. Now.... if the CS injector is stuck constantly open, that would be a huge problem right there. You would have to cap off the fuel supply to that injector or you will never be able to tune the car properly.

[This message has been edited by Joe 1320 (edited 03-14-2013).]

Racing_Master MAR 15, 11:35 PM
Got the injectors out today, it appears all 8 of them are leaky! the CSI appears wet however I am unsure if it's leaking. I'll leave it for now, and delete it later. The car should run better with the new 8 injectors I am installing tomorrow.

I also got my autometer gauges installed tonight! Oh boy does it make me feel excited seeing those things finally installed... been sitting around forever. After redneck wiring them in, I tested the fuel gauge and voltmeter, along with all illuminations, and everything is perfect! I lost the water temp sensor since I got the gauges, so I hope my stock one will suffice for now. I had to order a new oil pressure sender since I also lost that one... We'll see what happens! My speedometer still does not work due to it needing a new cable (Cable driven speedometer off of non-stock transmission). I think a cable from an 85 firebird will fit, I just got to ask GM about speedometer gear sizes and get the proper gear for the trans.
ARFiero MAR 17, 03:00 PM
What size injectors are you getting? The 305 only needs 19 pounders in stock form. You can buy a CSI delete from TPIS I believe. You also need the prom from a 305 TPI or a whole computer. also check to see if your TPI setup has a MAF or is Speed Density. The 88 Computer is set up for speed density so it should be right or it wouldn't run. The biggest thing is the fuel map and the spark control yu are running is not right for the small engine. It might be easier to get a 350 but you will need to get a pre-86 350 block unless you get an 87 or later lower intake which will get rid of the CSI for you. any questions about the TPI's send me a PM. I know all about their quirks.

Shelby
Racing_Master MAR 18, 11:07 PM

quote
Originally posted by ARFiero:

What size injectors are you getting? The 305 only needs 19 pounders in stock form. You can buy a CSI delete from TPIS I believe. You also need the prom from a 305 TPI or a whole computer. also check to see if your TPI setup has a MAF or is Speed Density. The 88 Computer is set up for speed density so it should be right or it wouldn't run. The biggest thing is the fuel map and the spark control yu are running is not right for the small engine. It might be easier to get a 350 but you will need to get a pre-86 350 block unless you get an 87 or later lower intake which will get rid of the CSI for you. any questions about the TPI's send me a PM. I know all about their quirks.

Shelby



I just got direct stock replacements, my CSI is just reinstalled but not plugged in right now, no problems. Right now, the car is working flawlessly! Much less oil burning (some from bad valve seals but that's common), idles smoothly, and has so much torque I can't get traction in first gear and some of second. I almost cant believe the old injectors were just THAT bad! my butt dyno says I probably have around 210rwhp or so now. the engine is such a mix mashup of parts... I have no clue what everything is! I now need to actually FIX my electric fan, and get rid of the flex fan so I can gain some extra ponies.
Raydar MAR 19, 11:04 PM

quote
Originally posted by ARFiero:
... also check to see if your TPI setup has a MAF or is Speed Density. The 88 Computer is set up for speed density
...



The 88 computer is still MAF. They didn't go Speed Density until 90, I think. Switched to a 7730.