1985 p30 fuel pump (electric) where is it?

PA85 · August 06, 2013, 07:03 PM

Ok guys this is my first post, so don't be to hard on me. Well i have a 1985 Pace Arrow 27' with a 454. My question for you all is, if i have no electric fuel pump in the tank or on the frame rail where else could it be? i have never heard a humming sound nor can i find any wires. I dont think it has one but it is a 1985 according to vin. From what i have been reading i thought it would be in the tank since i cannot find it on the frame. I have dropped the tank and it has only a sending unit. Thanks.

nalambright · August 06, 2013, 07:07 PM

Are you sure it doesn't use a mechanical pump mounted on the engine?

PA85 · August 06, 2013, 07:10 PM

Yes it has a mechanical on the engine. It is not pumping to the carb. So i started reading and found out about the electric one that i cannot find.

nalambright · August 06, 2013, 08:28 PM

I think they usually use either mechanical or electric. An electric pumping into a mechanical can blow the diaphragm and fill your crankcase with gas.

pvoth1111 · August 06, 2013, 08:36 PM

Electric one most likely in the tank.

PA85 · August 06, 2013, 08:55 PM

I have dropped the tank and it only has a sending unit.

bluebird · August 06, 2013, 09:14 PM

Maybe before the pump was added to the tank. My 80 Itasca had no pump in the tank, and it ran just fine. It was a 26 fter.

GONMAD · August 06, 2013, 09:40 PM

Hey guy's I just performed an electric pump & regulator install, I still use the mechanical as well. Look in my pics on how. C YA! GONMAD

DaveVA78Chieftain · August 06, 2013, 09:58 PM

As indicated in the Chevy MH Service Guide (available here in the free manuals section), Chevy did not start installing an electric fuel pump and frame rail regulator until 1985 1/2. That was an in tank version. They used a 1/2" fuel line. The electric pump was used to push the fuel up to the mechanical pump on the engine. The regulator insured the pressure was low enough to not damage the mechanical pump. The mechanical pump was retained until 1990 when they converted to a TBI system which only uses a electric pump.

Chevy did a study that resulted in the 1985 1/2 change. They also put together recommendations on how to add an external pump and regulator for pre 1985 1/2 rigs. All of this information and how to data is contained in Appendix 7-7 of the Chevy MH Service Guide.

Dave

PA85 · August 06, 2013, 10:34 PM

Thanks guys. I guess i have a 85 instead of an 85 1/2. So do you guys suggest going with a in tank or frame mount electric pump?
Or just run it with a new mechanical on motor?
I really did not like dropping this 60 gallon tank.

DaveVA78Chieftain · August 06, 2013, 10:44 PM

Frame mounted pump should be fine.

MotorPro · August 07, 2013, 07:33 AM

Just replace the mechanical pump. If you find you have a vapor lock problem on hot days (the reason they added an electric pump) you can then add a frame mount pump. If you do put it as close to the tank as possible.

legomybago · August 07, 2013, 10:27 AM

The inlaws have an 1986 Komfort 27' P30 thats been vapor locking this summer...it's been really hot here!! So I picked up a 6# Carter inline pump and will be placing it in back close to the tank. This rig did not come with an electric unit from the factory....I've had the fuel tank dropped, and replaced all rubber lines, and it has a new mechanical pump. My question would be......Is it better to run power from ignition switch for AO...Or toggle on dash and use when needed??

I prefer when needed, but inlaw wants always on...?

Froggy1936 · August 07, 2013, 11:39 AM

Hmm an 86 P30 should already have an electric pump in the tank ? But either way use a relay the frame mount pump pulls a lot of amps Frank

legomybago · August 07, 2013, 02:13 PM

Nope..had the sending unit in my hand...60 gallon tank on the ground

PA85 · August 07, 2013, 02:52 PM

My pace arrow is the same way (sending unit only). Well i know it is hot here in Arizona, I am sweating as I type. So I will look at the Carter inline also. My question would be......Is it better to run power from ignition switch for AO...Or toggle on dash and use when needed?? I prefer when needed, but inlaw wants always on...? I am wondering about this to.

MotorPro · August 07, 2013, 03:18 PM

I always run from the key but also add an inline switch incase I want to turn it off. Also make sure to add a fuse. If you really want it right you can add an oil pressure cut off switch.

GONMAD · August 07, 2013, 04:24 PM

Hey guy's Make SURE you use a pump with no less than a 3/8"line & pipe fittings. If you don't you WILL have a starvation problem under way. the 1/8" pumps do not flow enough VOLUME th supply a big block at speed. I just upgraded to a Holley GPH 110 with regulator set at 6 lbs. From the rear (see my pics) Sometimes called a "lift pump". We run dual fuel supplies for a backup. Plenty of room above the right rear too. I used old shock absorber rubber bushings for isolastic type mounting to eliminate noise transfer to the frame

bluebird · August 07, 2013, 06:25 PM

You need to run it off a relay that is run by the key switch. There are terminals on the fuse block that are hot only when the key is switched on, just make sure you install a in line fuse, and large enough wire, if you decide to go this way.

DaveVA78Chieftain · August 07, 2013, 06:54 PM

I recommend you install it in accordance with procedure recommended in the Chevy MH Service Guide (available here in the free manuals section). That way you know you are not missing anything AND it is a safe installation.

Dave

cncsparky · August 07, 2013, 07:08 PM

Quote from: PA85 on August 07, 2013, 02:52 PM
My pace arrow is the same way (sending unit only). Well i know it is hot here in Arizona, I am sweating as I type. So I will look at the Carter inline also. My question would be......Is it better to run power from ignition switch for AO...Or toggle on dash and use when needed?? I prefer when needed, but inlaw wants always on...? I am wondering about this to.

I would be concerned with the mechanical pump trying to pull fuel through an electric that wasn't on. Could make a vapor locking issue worse.

HandyDan · August 07, 2013, 07:58 PM

My mechanical will not pull gas through the electric. There was a picture on here somewhere that shows a by-pass for the electric when not in use. I'll see if I can find it unless someone comes up with it first.

DaveVA78Chieftain · August 07, 2013, 08:01 PM

QuoteI would be concerned with the mechanical pump trying to pull fuel through an electric that wasn't on. Could make a vapor locking issue worse.

I suppose that's why the GM design has a anti-siphon check valve built into it.

HandyDan · August 07, 2013, 08:06 PM

http://www.classicwinnebagos.com/forum/index.php/topic,5817.0.html

Try this thread. It has the picture I was thinkin about.

Froggy1936 · August 07, 2013, 10:02 PM

Since i installed the fuel injection I have the elec holly and the check valve for sale Send me a pm if interested Frank P.S. the original prices are in the referred to post