The car is a 91 RS originally a 305 but recently spun a bearing and i decided to go do a swap. Now it has a 350 in it and pretty much everything is new except the injectors and the fuel pump. I will be switching them out very shortly when more money comes my way but i have a few problems.

The shop that did the swap handed me the car with a surging idle and a bad alternator. I switched out the alternator myself and replaced the cooling temp sensor as that was the cause of the surging idle. However there is still a very small surge and my gauge only reads about 10 volts. What are the possible causes of this?

Finally in the back seat of the car was a shroud of some sort. It seems to go right where the engine and the tranny meet as i can see something spinning. Im not to good on technical terms so i hope you guys know what im talking about. Also i seem to have a lurch when i step on the car, it sounds like its coming from the area where this shroud would be at times and it also sounds like it could be coming from my rear end. It pretty much sounds and feels like the tranny or somehting around the tranny/rear engine area isnt bolted in correctly. Im just wondering if you guys know anything off hand that i should check out to comfirm if something is going wrong. The car will be in the shop on Monday getting re checked out hopefully but i would like to figure out this problem asap.

 

I am sort of confused on what you are saying. I would first break the motor in, dont slam on it just yet, and see if it goes way after some time. If it gets worse take it back surely

 

I'll start with the easier side.... that shroud should be the inspection cover that goes on the bottom of the trans. It helps keep dirt out and was designed to be there for that reason.... easy to put in place.

As for the surging and running problems.... Typically shops don't usually do engine conversions, just regular swaps to the same engine. Did you get a 350 chip pit in? I don't remember on TPI, but I know TBI had different injectors for the 305 and 350.

That sound you are hearing could easily be a tranny mount.... very typical on these cars. Check to see if that's the problem.... easy to change.

As for the alternator, the quickest checks are fuses, loose wires, and check the voltage with a multimeter(gauge could be off). If all else fails, then time to start troubleshooting.

 

The shop that did the swap is a specialty engine swap place. The car does have a 350 chip in it now the only thing its missing is the injectors and pump. The alternator is good and so is the battery i just had them checked today. i also switched out the ignition control module on top of the steering column as my uncle said that could be the culprit. My main concern now is the surging idle and the battery dying. It barely made it back home today and the volts are still only at 10. As i was driving home i watched them go all the way down below 8 as i coasted into a spot. I cannot figure out what is going wrong with this car, i cleaned off numerous electrical grounds, and tested the system numerous times today. Im not beating on the car in any way either, i put about 30 miles on her today before she died and never once took the rpms above 2300 or so.
SOrry if everything is confusing guys im just really pissed about this hole ordeal.

 

if the alternator is good it most likely isn't hooked up right or isnt grounded well enough.

 

Running 19lb injectors from a 305 wont cause the problem either, i ran 19lb ford injectors in my Z for years, and it ran fine.. swapped after a bout 20k to 24lb injectors.. using same chip, no problems.

Surging idle, possible they screwed with the TPS if your using the same TPI body from the 305.. first thing i would check. Also, are you getting any codes?

John
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Oh, just noticed your running TBI.. didnt read all the way lol.. Are you using the same TBI body off the 305?

 

Im not getting any codes except when the car stalls out. It throws a code and when i take out the key it goes away. I tried once to get the code but the scanner didnt read any. I also checked the grounds on the alternator and cleaned them. Today i also had the alternator off again and i gleaned up all the connectors and such. Ill check the TPS also but the shop that did the swap told me the Coolant Temp sensor was bad. I replaced that and it helped the surge quite a bit, now its just a slight surge, like 2-300 rpms that gets worse as the volts dont charge up eventually causing the car to stall out sometimes when i start it up.

 

On your charging problem, you might want to check all the grounds, especially the ones that hook up on the back of the cylinder heads. A lot of times when a shop swaps a motor in, these ground straps are often not hooked back up properly. The ones on the back of the heads are a PITA to get to, so they might've missed those either accidentally or on purpose. Once you're sure all your grounds are good, if it's still not charging properly, you can always swing by an Auto Zone and have them check it out for you. They'll roll their machine out there and do it for free, so why not? It's also possible that you ended up getting a faulty re-manned alternator. I've had that happen a couple of times.