Hi all, I am new here and new to Camaros, but not new to mechanic work. I just picked up a 1989 Iroc-z with the 5.7L TPI in it. I am having an issue with starting as well as a miss at idle.

The starting is the most pressing issue. One minute it will start fine, then if I kill it, it won't start back up. One blast of starter fluid in the intake and it fires right up and stays running. Heck I drove it over 100 miles to get it home.

It is also missing badly at idle, enough to shake the whole car. Revving it above 2K rpm smooths it out, but I still feel the miss.

The plugs, cap and rotor was replaced 10K miles ago by the previous owner. The plug wires do look old on it and they are first on my hit list. Fuel pressure is 50PSI at the rail. The previous owners had this problem since 02. They took it to several dealerships and they replaced the alternator twice, then the cap, rotor, and plugs, then the fuel pump and filter and one fuel injector. All of this is confirmed by receipts.

I have found several wires that have been cut, then spliced to 12V leads around the engine bay and the primary ground cable had a new end spliced on it and it was attached to a valve cover bolt. I moved this to the block and the idle miss smoothed out, but didn't go away completely. It hasn't been driven much in the last two years, so I have put fresh gas in it.

Anyone have any ideas about what could be wrong here?

 

Could be another bad injector. I know that they aren't cheap, but you can get a set of 8 on ebay for your 350 shipped to your door for like $160. There's eight injectors on your car and I personally don't know a way to check and see if injectors are good or not so replacing one injector does not make any sense to me. The 350 uses 22 pph injectors. If the plugs, cap, rotor and wires all have been replaced and the wires inside the distributor leading to the ignition control module all look good then I would go to injectors.

 

i would double check the plug wires first as they are the cheapest to replace. pull one off at a time and check for spark with a test light. the test light wont light up, but will allow it to safely arc to ground without hurting the coil. ive deal with brand new plug wires that have had an internal break or the ends werent secure and needed replaced. if that checks out, do you have a digital temp gun or some way of attaching an oven thermomete to the exhaust manifold? this will tell you to which cylinder is missing.

 

I just picked up the wires tonight and I will install them shortly. Checked the wires going to the coil and they were fine, no splicing or other issues there. I have a small fortune in reciepts from dealer work on this car, so I can imagine why he didn't replace all of them, especially since Chevy was charging $173 a pop on em. I will post back with the results of the wires.

 

alrighty. and for the hard start, does it matter if the engine is hot or cold? how long does it usually crank for, and does it sputter at all while cranking? does it seem really rich when it first fires, then goes back to normal?

 

Plug wires didn't help. There were a few that were heat damaged, so it's not too bad. On a side note, the number 8 plug is a ***** and a half to get at. Got my trusty stethoscope out and went to checking the injectors. 3 of them weren't ticking as loud as the other 5. Unplugging them didn't change the motor speed in any way. Looks like I am going injector hunting.

As for the hard starting, it doesn't matter if it's hot or cold. I can crank it for 30 seconds or so and it never will fire. On hit of starter fluid and it fires on the first or second crank. If it does decide to fire without the fluid, it sputters for a few cranks and then fires up. And yes, it seems a bit rich when it cranks, then smells pretty normal.

 

yea, it sounds a bit like bad injectors. they either arent opening all the way, or are stuck open. i was thinking maybe the cold start injector, but i dont think that was on the 89. you might be able to find a local shop that could do an injector balance test if you pull them out. they can be a bit of a pain to get out, removal of the upper plenum and possibly the runners is required. be careful with the fuel rail as everything is aluminum and easily damaged. the injectors should just pop off the intake, although i dont recall how they are secured to the fuel rail

 

The injectors are just press fit into the intake then have a clip to the fuel rail. The fuel rail is held in by 4 screws I think. http://cgi.ebay.com/ebaymotors/89-90...Q5fAccessories Is the posting on ebay for those injectors I was talking about. They seem like a good deal, or you can go to jegs and get their venom injectors, http://www.jegs.com/i/Venom/735/HP-623-8/10002/-1 which will cost a little bit more. It's all up to you, but let me know if you end up having to take off the runners, because I'm going to replace my injectors pretty quick and it would be cool if you didn't have to take them off

 

I will let you know how it goes. I got horribly sick and have been completely out of it for the past few days.

 

i was just looking at my fuel rails to refresh my memory as to why i took it out as one peice. there are a few aluminum tubes that run across the rails as well as the fpr. i left them attached because i know the nature of aluminum and that its very easy to strip the threads. i also think they were seized together. i dont remember if the 4 bolts are possible to get to with the runner and plenums attached, but if you have a ratcheting wrench, you may be in luck.